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Just a dumb question but is the cdi the right one for this sled? It just occurred to me that I had a 98 F3 700 that had a wrong CDI installed and it would do exactly what your experiencing. Would start run ok for a few seconds sometimes longer but as soon as you touched the throttle, it would blow black smoke and crap out.
 

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Discussion Starter · #42 ·
Just a dumb question but is the cdi the right one for this sled? It just occurred to me that I had a 98 F3 700 that had a wrong CDI installed and it would do exactly what your experiencing. Would start run ok for a few seconds sometimes longer but as soon as you touched the throttle, it would blow black smoke and crap out.
I honestly can't say for sure but it looks like it's the original part.
I'm fairly certain the ignition system is working fine.
Now that I have the engine out AGAIN, it's getting crank seals and a thorough going over. I've previously experienced a crank seal problem that acted similar but it was on a twin. Maybe the Reed valves are the problem, I don't know.
. I'll tear it down when/if I regain my sanity in the coming weeks.
 

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Putting the engine back in to diagnose the problem may help with the sanity. If a crank seal leaks it affects only one cylinder, not two. If I can run a triple with a open pulse line on the pto side by manually feeding three individual carbs, I don't see how a tiny leak through through one of the two crank seals will have a considerable impact, let alone affect two cylinders. Replacing crank seals can't hurt if done correctly, and it does give the opportunity to inspect the coolant pump by removing the cover. So this is good, but in an order that may cause added grief if the seals end up not being the problem.
 

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Discussion Starter · #44 ·
I realize it's a long shot and grasping, but I've been cursing at this thing for far too long now. Figured I'd start over and cover all possibilities. Maybe I missed something the first time I had it out.
To be honest I didn't really take a hard look at it the first time out as I mainly pulled it out to access and repair the main wiring harness.
Maybe the reeds have issues, Another maybe.
There has been so many maybes that I've already tried and getting tired of being defeated.
My logic, possibly flawed , is that with that boost bottle setup , one cylinder having a problem could affect the next cylinder. Another maybe.
Carbs have been cleaned and checked over many times, ignition appears to be fine and have 125# comp across all 3 .
Technically speaking , the [email protected]%&€ thing should run.
If nothing else, it will eliminate a couple of possibilities.
Changing the seals isn't a big deal or overly expensive, hopefully, with the engine sitting on the bench.
I only have about $300 into it , so far , but my frustration level is at a all time high.
I doo appreciate all the input from everyone and hopefully there is a light at the end of the tunnel without it being another damn train.
I live just a little past, the middle of nowhere, so getting parts is a pain in the ass. The closest Doo dealer is 1.5 hrs away and I'm very leary of using aftermarket parts.
 

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Even compression and the engine idling fine is a huge step in the right direction. To me it proves that you have done good work. When throttling-up causes it to backfire, then I know it is either loosing spark or gas under load. It leads to the plugs fouling and poor idling, so the plugs needs to be cleaned. This can be done on a wire wheel or by heating the plug with a handheld torch. And crank the engine without the plug to make sure there is no flood, especially the cylinder that has the pulse line to the fuel pump. My 779 is on the center, but I think your 600 is on the mag side. From there I focus on ignition and gas. The fact that it idles - at least with clean plugs - that simplifies everything.

Before the help that I got from following DooTalk, I was troubleshooting blind. Just like in this thread there are folks who have spent years in the shop working on hundreds of snowmobiles. I don't have have anywhere near that level of experience, so I have had to learn from DooTalk, BRP techs and independent shops. Through doing I was able to develop my own troubleshooting methods with things like using a timing light that happened by fluke/chance. The best tool that I have learned through DooTalk is to write out the troubleshooting steps. It has a way to help me think of what I have forgotten or neglected to check. When you said technically speaking it should run, this is exactly what I am referring to. A buddy of mine had bought a vintage twin that had not started in years, and brought it over so that we could work on it together. After seeing the spark was visibly strong I was certain it would start within a few pulls, but it didn't. With even compression, good spark, fresh fuel, it had to start, there was no other way. My old eyes could not see the spark was arching too far until I used a magnifying glass while my buddy was cranking the engine.

A couple more things, it is a bad idea to run the engine without the clutch, and it doesn't run right without it. I don't suspect any crank phasing issue, but it is worth checking. No fancy tools needed. Just mark TDC on the clutch for each cylinder. With a sewing tape or a degree wheel printed on paper and glued to a piece of cardboard, it is easy to find a cylinder that is off by 5+ deg. Hopefully this helps if needed once the seals have been replaced. I'm rooting for you.
 

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Discussion Starter · #46 ·
Even compression and the engine idling fine is a huge step in the right direction. To me it proves that you have done good work. When throttling-up causes it to backfire, then I know it is either loosing spark or gas under load. It leads to the plugs fouling and poor idling, so the plugs needs to be cleaned. This can be done on a wire wheel or by heating the plug with a handheld torch. And crank the engine without the plug to make sure there is no flood, especially the cylinder that has the pulse line to the fuel pump. My 779 is on the center, but I think your 600 is on the mag side. From there I focus on ignition and gas. The fact that it idles - at least with clean plugs - that simplifies everything.

Before the help that I got from following DooTalk, I was troubleshooting blind. Just like in this thread there are folks who have spent years in the shop working on hundreds of snowmobiles. I don't have have anywhere near that level of experience, so I have had to learn from DooTalk, BRP techs and independent shops. Through doing I was able to develop my own troubleshooting methods with things like using a timing light that happened by fluke/chance. The best tool that I have learned through DooTalk is to write out the troubleshooting steps. It has a way to help me think of what I have forgotten or neglected to check. When you said technically speaking it should run, this is exactly what I am referring to. A buddy of mine had bought a vintage twin that had not started in years, and brought it over so that we could work on it together. After seeing the spark was visibly strong I was certain it would start within a few pulls, but it didn't. With even compression, good spark, fresh fuel, it had to start, there was no other way. My old eyes could not see the spark was arching too far until I used a magnifying glass while my buddy was cranking the engine.

A couple more things, it is a bad idea to run the engine without the clutch, and it doesn't run right without it. I don't suspect any crank phasing issue, but it is worth checking. No fancy tools needed. Just mark TDC on the clutch for each cylinder. With a sewing tape or a degree wheel printed on paper and glued to a piece of cardboard, it is easy to find a cylinder that is off by 5+ deg. Hopefully this helps if needed once the seals have been replaced. I'm rooting for you.
I do appreciate any and all information.
Funny thing , today I worked up a little courage to start tearing it down. Decided to start with the reeds and found out it has V force 3s in it.! Woooo.!! So obviously someone has been tinkering with it. To bad they didn't put any gaskets between boots and reeds. Hmmmm. Another maybe,!
 

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When you started tearing into it today, did you happen to check the part number on the CDI? It could be the right one/original, or maybe the fire damaged it. This is kinda sounding like a timing issue.
 

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I do appreciate any and all information.
Funny thing , today I worked up a little courage to start tearing it down. Decided to start with the reeds and found out it has V force 3s in it.! Woooo.!! So obviously someone has been tinkering with it. To bad they didn't put any gaskets between boots and reeds. Hmmmm. Another maybe,!
My hope is that it helps to work through things, like a sounding board of sorts. Like many on DooTalk I have built my own leak test kit and often find the reed boots that are leaking around the mating surface that sits against the cylinder intake track. I used to worry about these things when I first built my kit, but not so much anymore after seeing so many leaks. I'm not saying it is ok, but rather it takes a considerable leak before I start to worry like a torn boot. The majority of Ski-Doo engines in the past 20 years don't even use gaskets, so when they leak I apply high temp sealant. For a quick seal to complete a leak test I use Dow 111 grease, because when those reeds leak I can't hear any other leak. I would suggest to leak test your triple if it wasn't a pain to plug the exhaust side. Unfortunately it has become a lost art in today's fast world.
V-force are a good reeds. Today's oem reeds for the 600R/800R/850 are the cream of the crop to survive a fueless base. Aftermarket replacement reeds makes a big difference in affordability. Out of all aftermarket reeds, V-Force is my preference with a quality product. Regardless of the brand, I always look for worn tips and open each petal with my finger to make sure none of them are sticky, and if so I clean them. Sticky reeds is not common, but it can happen during storage. You have three sets of reeds, so if one sticks then it will be obvious.

The greatest effect of reeds is during idle and next the lower throttle positions. Assuming it was idling ok on all three cylinders, then the reeds should be ok. Remember to never run the engine without the clutch. Triples will give the sense of being able to get away with it, but it is not so. The mass of the clutch is the most important part to keep the engine running smoothly. Note how much easier it is to crank over the engine with the clutch.
 

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Discussion Starter · #49 · (Edited)
When you started tearing into it today, did you happen to check the part number on the CDI? It could be the right one/original, or maybe the fire damaged it. This is kinda sounding like a timing issue.
I find it interesting how you are so certain it's the ignition when it appears to be working fine, and totally disregard missing gaskets.
Who knows, you could very well be right. I won't dismiss anything at this point.
The number on unit is
Denso 070000-2341

PS The fire never touched it or the wiring around it. Mostly burnt main wiring harness from bottom of engine to the oil tank.
Everything works as its supposed to electrically.
None of the ignition wiring was burnt.
 

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Discussion Starter · #50 · (Edited)
My hope is that it helps to work through things, like a sounding board of sorts. Like many on DooTalk I have built my own leak test kit and often find the reed boots that are leaking around the mating surface that sits against the cylinder intake track. I used to worry about these things when I first built my kit, but not so much anymore after seeing so many leaks. I'm not saying it is ok, but rather it takes a considerable leak before I start to worry like a torn boot. The majority of Ski-Doo engines in the past 20 years don't even use gaskets, so when they leak I apply high temp sealant. For a quick seal to complete a leak test I use Dow 111 grease, because when those reeds leak I can't hear any other leak. I would suggest to leak test your triple if it wasn't a pain to plug the exhaust side. Unfortunately it has become a lost art in today's fast world.
V-force are a good reeds. Today's oem reeds for the 600R/800R/850 are the cream of the crop to survive a fueless base. Aftermarket replacement reeds makes a big difference in affordability. Out of all aftermarket reeds, V-Force is my preference with a quality product. Regardless of the brand, I always look for worn tips and open each petal with my finger to make sure none of them are sticky, and if so I clean them. Sticky reeds is not common, but it can happen during storage. You have three sets of reeds, so if one sticks then it will be obvious.

The greatest effect of reeds is during idle and next the lower throttle positions. Assuming it was idling ok on all three cylinders, then the reeds should be ok. Remember to never run the engine without the clutch. Triples will give the sense of being able to get away with it, but it is not so. The mass of the clutch is the most important part to keep the engine running smoothly. Note how much easier it is to crank over the engine with the clutch.
The reeds are like new. According to the Doo parts list there is gaskets between boots and reeds but both surfaces are rubber covered and might be sealing so I'm not really optimistic that it's the problem. I will be putting gaskets in on reassembly. I wouldn't run it without the clutch and the belt on. I really don't want to blow it up.
It hasn't really ever ran on all 3 at the same time. #3 was fairly consistent with 1 and 2 taking turns . Strangly it ran better with a sticky plunger. It actually seems to be getting worse which is why I'm suspicious of the crank seals.
Pretty much grasping at straws now and starting to wonder if I really want to sink much more into this old money pit.
 

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The reeds are like new. According to the Doo parts list there is gaskets between boots and reeds but both surfaces are rubber covered and might be sealing so I'm not really optimistic that it's the problem. I will be putting gaskets in on reassembly. I wouldn't run it without the clutch and the belt on. I really don't want to blow it up.
It hasn't really ever ran on all 3 at the same time. #3 was fairly consistent with 1 and 2 taking turns . Strangly it ran better with a sticky plunger. It actually seems to be getting worse which is why I'm suspicious of the crank seals.
Pretty much grasping at straws now and starting to wonder if I really want to sink much more into this old money pit.
That changes things. If it never idled on all 3 and 2 of them are taking turns to fire, then it could be running out of electrical power. This is of course only if the plugs have been cleaned each time they fouled. This is why I use a timing light.
 

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Discussion Starter · #52 ·
That changes things. If it never idled on all 3 and 2 of them are taking turns to fire, then it could be running out of electrical power. This is of course only if the plugs have been cleaned each time they fouled. This is why I use a timing light.
I've used a spark tester several times and always have spark. Getting it to run long enough to use a timing light is a pipe dream.
I cleaned the plugs a few times but no real improvement. It is becoming very frustrating and I'm starting to wonder where I should draw the line at wasting money.
 

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I've used a spark tester several times and always have spark. Getting it to run long enough to use a timing light is a pipe dream.
I cleaned the plugs a few times but no real improvement. It is becoming very frustrating and I'm starting to wonder where I should draw the line at wasting money.
I figure that 9 times out of 10 it is something simple, so I have learned to focus on the 90%. Like most people I fear the complicated 10% and that's where I usually get into trouble lol

Was the spark tester in series to the plug while you were throttling up? If so, then that confirms the ignition is good. But you did say there is little chance to get the engine running long enough which has me wonder. I leave the timing light on the floor pointed against a wall just to see it strobbing, so the moment the engine starts I can see it. The spark tester is fine, although I have never had good luck with mine. I'm just explaining the part that I'm not quite sure that I follow.

For the money part, with even compression it is probably worth spending a few dollars. A part-outs is a good way to go for whatever was broken with the RAVE. You will get through this, but first it is important to let the dust settle from this recent experience. You have worked on this engine and know it better than anyone. If you give yourself the chance, your mind will gradually get rid of the weeds and work it out.
 

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Discussion Starter · #54 ·
I figure that 9 times out of 10 it is something simple, so I have learned to focus on the 90%. Like most people I fear the complicated 10% and that's where I usually get into trouble lol

Was the spark tester in series to the plug while you were throttling up? If so, then that confirms the ignition is good. But you did say there is little chance to get the engine running long enough which has me wonder. I leave the timing light on the floor pointed against a wall just to see it strobbing, so the moment the engine starts I can see it. The spark tester is fine, although I have never had good luck with mine. I'm just explaining the part that I'm not quite sure that I follow.

For the money part, with even compression it is probably worth spending a few dollars. A part-outs is a good way to go for whatever was broken with the RAVE. You will get through this, but first it is important to let the dust settle from this recent experience. You have worked on this engine and know it better than anyone. If you give yourself the chance, your mind will gradually get rid of the weeds and work it out.
This is what has me stumped as well. I'm usually fairly competent with this kind of stuff and pretty much gone over all the usual issues. The Last time I got this stumped on a running issue on a sled, not a triple, it was the crank seals,and kind of why I'm leaning that way.
I'm more surprised that nobody seems to be on board with me on this possibility.
Yes I was using a inline spark tester and it never looses spark.
I managed to bust a exhaust valve that is obsolete of course but the Doo dealer up here has one for mere $105.
I've been battling this thing for 3 months now and have run out of ideas and patience. This is why I've turned to you guys to try sorting this out. I do have a nasty temper at times and sometimes it gets the better of me so I need to take a break before I do something I'll regret.
I'm waiting on a clutch puller, and intake gaskets, (more $$$) that I ordered and trying to stay away but it keeps taunting me.
The big issue is someone has obviously been tinkering with it so this could be a ongoing problem and why the guy abandoned it. Maybe.
I'm going to at least have a look at the seals and almost hope that it is the problem but not betting on it.
I'm starting to get concerned about the cost of parts snowballing.to the point of not being worth it.
It is in good condition and fairly low mileage, 4500 m ,but when do I raise the white flag and cut my loses on a 24 yr old sled.
I have 2 very reliable, older I#&y 500s, that I can hear laughing thier asses off at me.! Not good !!
I'll take a little break from it to regain my sanity but winter is coming, hopefully.
 

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This is what has me stumped as well. I'm usually fairly competent with this kind of stuff and pretty much gone over all the usual issues. The Last time I got this stumped on a running issue on a sled, not a triple, it was the crank seals,and kind of why I'm leaning that way.

I'm more surprised that nobody seems to be on board with me on this possibility.

Yes I was using a inline spark tester and it never looses spark.

I managed to bust a exhaust valve that is obsolete of course but the Doo dealer up here has one for mere $105.

I've been battling this thing for 3 months now and have run out of ideas and patience. This is why I've turned to you guys to try sorting this out. I do have a nasty temper at times and sometimes it gets the better of me so I need to take a break before I do something I'll regret.

I'm waiting on a clutch puller, and intake gaskets, (more $$$) that I ordered and trying to stay away but it keeps taunting me.

The big issue is someone has obviously been tinkering with it so this could be a ongoing problem and why the guy abandoned it. Maybe.

I'm going to at least have a look at the seals and almost hope that it is the problem but not betting on it.

I'm starting to get concerned about the cost of parts snowballing.to the point of not being worth it.

It is in good condition and fairly low mileage, 4500 m ,but when do I raise the white flag and cut my loses on a 24 yr old sled.

I have 2 very reliable, older I#&y 500s, that I can hear laughing their asses off at me.! Not good !!
I'll take a little break from it to regain my sanity but winter is coming, hopefully.
It sounds to me like you are holding it together despite the adversity from this stubborn problem. I am impressed that you had the balls to post your trials and tribulations on an open forum. Engine be damned, the only thing that matters is you. Perhaps the feelings of the two Indys matter too lol
 

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Discussion Starter · #56 · (Edited)
It sounds to me like you are holding it together despite the adversity from this stubborn problem. I am impressed that you had the balls to post your trials and tribulations on an open forum. Engine be damned, the only thing that matters is you. Perhaps the feelings of the two Indys matter too lol
Wanted to make sure I provided as much information as possible to try and figure out what the hell is wrong with this thing. Don't want to overlook anything.
Devil's in the details they say.

I'm too old to give a damn about admitting my trials or tribulations. Lol

Those Indys are the best damn sleds I've ever had. Not the best suspension by any means (apparently a M10 would fix that) but definitely the most dependable sleds ever made. Sorry.
Hope I don't get banned for that.

I have high hopes for this F3 but lately I'm starting to think that the F stands for something else. Certainly been using it a lot lately.
I will continue my quest, at least until the expenses override my interest. Already starting to add up quickly and still no light at the end of the tunnel.
 

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Wanted to make sure I provided as much information as possible to try and figure out what the hell is wrong with this thing. Don't want to overlook anything.

Devil's in the details they say.

I'm too old to give a damn about admitting my trials or tribulations. Lol

Those Indys are the best damn sleds I've ever had. Not the best suspension by any means (apparently a M10 would fix that) but definitely the most dependable sleds ever made. Sorry.

Hope I don't get banned for that.

I have high hopes for this F3 but lately I'm starting to think that the F stands for something else. Certainly been using it a lot lately.

I will continue my quest, at least until the expenses override my interest. Already starting to add up quickly and still no light at the end of the tunnel.
F is for formidable, but it needs to be said with a french accent.

I imagine that you have owned or ridden a triple-triple. Such a sweet sound and smooth running engine. That should be incentive enough to get it running. I need to get an engine to at least idle on all cylinders to get rid of the noise - fear- frustration, etc. It is easier than repairing holes from flying wrenches lol All this needs is to unplug fuel pump and squirt premix through the carbs. As long as the crank is in phase and there is compression with a clean spark, then is has to work. There is no maybe. It has to work, must work, is going to work. If you have never done this and remain unsure, then practice with your push mower. Pinch the gas line or remove it from the carb and block it off with a bolt. Then remove the air filter and learn how to make it run by manually feeding it premix. It is a religion. All you need is faith and practice to join lol

There is a thread about this on DooTalk if you are interested. It even shows how much XPS oil a 4S can run on and still have plenty power to mow the grass. You read that right, a 4S running on premix. If you think that 40:1 is a lot of oil, think again. It is not good enough to read about it or watch a video. It only counts if you do it yourself. Added oil also helps with low compression engines. If you are also not sure about this, we can work it together and prove it to ourselves. I have already done the work, but I will gladly do it again if you are interested in a team effort. While the triple impatiently awaits her new owner to get a grip so that she can give him the ride of his life, we might as well do something useful lol

The only 2S oil that I would feed her is XPS/BRP, but I would have no trouble using any 2S oil from either Polaris or Arctic Cat. Those three are the cream of the crop. No one else spends millions of $,$$$,$$$ and countless hours of testing to develop 2S oil for snowmobiles that are running exceptionally lean. So if you are using Polaris oil for your Indy's, then use the same oil for your Ski-Doo triple. It will run on any 2S oil so don't rush to the store on my account. But if you are looking for the best, those are the 3 brands.

By the way, I don't think those Indy's are laughing. They are nervous and staying quiet thinking better the FIII than us lol
 

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I just spoke to a buddy of mine who told me those crank seals can cause runability issues like you are having. It does not change the fact that I have never seen it, but apparently it is a thing. I did bring up my experience with getting all two or three cylinders to idle despite any kind of leak, and he confirmed that that running the engine from carbs versus manual injections were two separate things. I did not want to suggest performing a leak test due to the time and effort needed for the setup, but he is adamant that it needs to be done.

I have spent literally hours over multiple phone calls just to help put one of these kits together, not to mention any of the others. The experience has taught me to not even bother suggesting it because it is either too scary for most owners to even attempt, or the amount the help needed to get a kit together requires an abnormally amount of hands-on input. Picture me on the phone with someone at the auto parts stored asking me if this or that part will work to build the kit. It was a pleasure that one time, but the thought of this repeating was overwhelming.

In this particular case, I have given the effort to show that I was in it for the long haul, but know that the amount of detail needed to build these kits is largely overwhelming. As I wrote in an earlier reply, I don't promote the test because it is considered by most owners to being too involved. And why would I even suggest something that I know from experience won't happen? And even if it did happen, I have no way to answer the hard questions that follow. In other words I have multiple reasons to avoid even suggesting it.

I am only mentioning this test because I asked a buddy of mine about your challenge and was told this was the way to go. I have my own experiences and methods, but since he gave two similar experiences for a Ski-Doo triple-triple and Yamaha twin, I figured that it was worth sharing.
 
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