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Crazy Person
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Discussion Starter · #1 ·
I was doing my regular maintenace and figured I'd post some results. All compression tests were done using the same tester and the testing method was the same including engine temperature (room temperature after sitting overnight in the garage)

1st Compression Test at 2400 Km's: 151/153

2nd Compression Test at 4000 Km's: 142/144

3rd Compression Test at 5600 Km's: 133/135

Notice from the numbers that every 1600 Km's the compression drops exactly 9 PSI per side, and that the difference between both sides has been constant.

Any thoughts from the experts? Do those numbers sound like normal wear?

After pulling the E-RAVE's from what I can see (just based on appearance only) the rings look good and so do the pistons.

I've been running Shell Snow Advance Ultra oil and my E-RAVE's come out as clean as a whistle, it really is unbelievable. They slide out without any difficulty and the only residue is a light build-up of carbon on the end of the guillotine's.

When I was following the shop manual it said the E-RAVE's on SDI's and Power TEK's actually remain shut until the TPS (Throttle Position Sensor) detects you are at 50% throttle or approximately 7400 RPM before they begin to open. I found that kind of high, no? It said it improves fuel economy and power in the low to mid range. So unless I read it wrong if this is true, it would explain why some guys RAVE's are so hard to remove, if you are just riding on groomed trails all the time, the valves are staying shut and building up with more carbon than mine would because I'm able to open it up on a lake during 90% of my ride since we have so many water bodies up here.

The manual also explains how the solenoid for the E-RAVE's works. There is a hose that feeds crank pressure to the solenoid. When the TPS detects over 50% throttle, pressure is released by the solenoid to the actual RAVE's. There is also a hose that releases any excess pressure, and it is linked with the TPS as well I think. The manual mentions that the E-RAVE's solenoid is electrically heated to maintain proper operation in cold temperatures, and the solenoid should be warm to the touch after your engine has been running 30 seconds. Good thing to keep in mind should you experience top end loss due to the solenoid not operating the RAVE's properly. I think it is cool how air pressure from the crank makes these valve's open and close according to your throttle position.

I want to thank Deadman for helping me out with some questions I had.

These shop manuals are awesome to read if you find this stuff interesting.

 

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Shoooow meeee the POWDER!!
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Anything special about taking the E-RAVES out compared to a non E-RAVE sled? Just curious as to when I do mine at the end of the season. Thanks!
 

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Crazy Person
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Discussion Starter · #5 ·
99MXZ600 said:
Anything special about taking the E-RAVES out compared to a non E-RAVE sled? Just curious as to when I do mine at the end of the season. Thanks!
[snapback]295390[/snapback]​
There is a hose connected to them that is in place with a zip-tie. You need to remove the zip-tie (make sure you don't cut the hose though) then pull the hose off, and everything else is the same for cleaning.

I didn't disassemble the RAVE's themselves, I just slid them out from the engine and left everything attached to the guillotine and cleaned them like that. I left the bellows alone and didn't remove the guillotine's from the bellows or anything, and I didn't screw with the springs that were on the bellows.

Be careful not to puncture the bellows or anything. Any air leak will cause them to malfunction. Make sure you zip-tie the hose back in place during re-assembly.

 

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Wow, guess you can't complain. Any of us here would probably kill at the opportunity to put so many miles on in a single season to force a re-ring job on a brand new sled. Plus, give you another reason to have a couple cold ones.

If it were me, I would get a set of cudney rings and see which ones last longest!! you still have time!
 

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Yellowknife said:
99MXZ600 said:
Anything special about taking the E-RAVES out compared to a non E-RAVE sled? Just curious as to when I do mine at the end of the season. Thanks!
[snapback]295390[/snapback]​
There is a hose connected to them that is in place with a zip-tie. You need to remove the zip-tie (make sure you don't cut the hose though) then pull the hose off, and everything else is the same for cleaning.

I didn't disassemble the RAVE's themselves, I just slid them out from the engine and left everything attached to the guillotine and cleaned them like that. I left the bellows alone and didn't remove the guillotine's from the bellows or anything, and I didn't screw with the springs that were on the bellows.

Be careful not to puncture the bellows or anything. Any air leak will cause them to malfunction. Make sure you zip-tie the hose back in place during re-assembly.


[snapback]295397[/snapback]​
Ok...thanks!
 

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Yellowknife said:
I was doing my regular maintenace and figured I'd post some results. All compression tests were done using the same tester and the testing method was the same including engine temperature (room temperature after sitting overnight in the garage)

1st Compression Test at 2400 Km's: 151/153

2nd Compression Test at 4000 Km's: 142/144

3rd Compression Test at 5600 Km's: 133/135

Notice from the numbers that every 1600 Km's the compression drops exactly 9 PSI per side, and that the difference between both sides has been constant.

Any thoughts from the experts? Do those numbers sound like normal wear?

After pulling the E-RAVE's from what I can see (just based on appearance only) the rings look good and so do the pistons.

I've been running Shell Snow Advance Ultra oil and my E-RAVE's come out as clean as a whistle, it really is unbelievable. They slide out without any difficulty and the only residue is a light build-up of carbon on the end of the guillotine's.

When I was following the shop manual it said the E-RAVE's on SDI's and Power TEK's actually remain shut until the TPS (Throttle Position Sensor) detects you are at 50% throttle or approximately 7400 RPM before they begin to open. I found that kind of high, no? It said it improves fuel economy and power in the low to mid range. So unless I read it wrong if this is true, it would explain why some guys RAVE's are so hard to remove, if you are just riding on groomed trails all the time, the valves are staying shut and building up with more carbon than mine would because I'm able to open it up on a lake during 90% of my ride since we have so many water bodies up here.

The manual also explains how the solenoid for the E-RAVE's works. There is a hose that feeds crank pressure to the solenoid. When the TPS detects over 50% throttle, pressure is released by the solenoid to the actual RAVE's. There is also a hose that releases any excess pressure, and it is linked with the TPS as well I think. The manual mentions that the E-RAVE's solenoid is electrically heated to maintain proper operation in cold temperatures, and the solenoid should be warm to the touch after your engine has been running 30 seconds. Good thing to keep in mind should you experience top end loss due to the solenoid not operating the RAVE's properly. I think it is cool how air pressure from the crank makes these valve's open and close according to your throttle position.

I want to thank Deadman for helping me out with some questions I had.

These shop manuals are awesome to read if you find this stuff interesting.


[snapback]295359[/snapback]​
Glad to help out. I knew you'd get those Rave's out without a problem once you knew what you had to do. Its simple, but nice to be prepared before you just start tearing apart a high tech piece of machinery.

I think I'm opting for a PT800 next year, so get some more miles on yours and keep me posted on how it does!
Do you get that stumble that a bunch of guys are complaining about in the lower midrange?
 

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Yellowknife

Is your current cylinder reading out of spec. Does that number mean you have to freshen the top end. You say you have the shop manual; what does it say for that. I have nothing but good to say for my PT. No stumble, just great power and gas mileage. Well, the oil consumption issue is one thing I have to fix. I've got 1300 miles on mine; I'm going to do a compression test and post on this thread later. How did you do your testing. Did you just hook up a gague and pull the cord a few times or did you do it another way.
 

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Doo Pilot
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Hey bwalker ,if you knew what you were talking about ! we would listen !
Go run your poo an sell your doo ,so we don't have to hear it !

Yellowknife is our bench mark for wear items ,he gets the most miles.
Yellowknife keep us posted those are good #'s
Your plugs are looking real good right? nothing looking likes going lean on any side?

Rich
 

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bwalker said:
Sounds like its time for a rebuild. I would bet your pistons are out of spec as well.
[snapback]295498[/snapback]​
Just a question......Why would you intentionally tear a perfectly good engine apart and have someone screw it up by replacing the rings?......or pistons?....
A factory engine will always last longer than a rebuild.....
If it aint broke, don't fix it.....
 

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I am suprised that the compression has dropped off so much with only 3500 miles. My sled has 2800 miles on it and I thought it should make it to 5000 this year without any noticeable wear, but if you have already lost nearly 20 psi I would have to say that by 5000 you could need attention.
 

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Crazy Person
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Discussion Starter · #14 ·
Deadman said:
Do you get that stumble that a bunch of guys are complaining about in the lower midrange?
[snapback]295414[/snapback]​
No. I had it in the beginning before the sled was broken in, then it went away.

SnoProG said:
Yellowknife

Is your current cylinder reading out of spec. Does that number mean you have to freshen the top end. You say you have the shop manual; what does it say for that. How did you do your testing. Did you just hook up a gague and pull the cord a few times or did you do it another way.
[snapback]295473[/snapback]​
My current cylinder reading? I don't know if those numbers are good or not...by the opinions here it looks like they are wearing thin. I'm waiting to hear back from my dealer. I'm going to Whitehorse in March and I don't want to be stuck with questionable motor conditions by then, that's why I'm looking into this now. I want to keep the engine up to par. I'll have to look at the shop manual further about more specs. For testing, I took out both plugs, put the tester on, held the throttle wide open and used the electric start until the needle on the guage wouldn't climb any higher. My numbers aren't the most important thing here, because so many guages can read differently. I think the key is that we've seen the numbers drop at a certain rate, and that's what I need to look at, as in, how much longer should I go before doing some work on it, etc. Sounds like many of you think it should be re-rung now.

GSX800HO said:
Your plugs are looking real good right? nothing looking likes going lean on any side?

Rich
[snapback]295530[/snapback]​
Rich, plugs look good, WOT on the lake, kill the motor, good plugs - light brown, consistant on both sides.

duck899 said:
Just a question......Why would you intentionally tear a perfectly good engine apart and have someone screw it up by replacing the rings?......or pistons?....
A factory engine will always last longer than a rebuild.....
If it aint broke, don't fix it.....
[snapback]295566[/snapback]​
That's my theory as well, but if the advice is to do some preventative work so I don't end up with larger problems down the road then...

Still gathering opinions, and reading up on things. Thanks everyone.
 

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Doo Pilot
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I would like to know how many Hrs he has on the motor !
Mileage is one thing but hrs running is another.
When you stop on a trail or anywhere you don't always shut down !
So the engine is still running ,so Hrs would be a better number to look at .Just like we do with boats.

Rich
 

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I did a compression test on my sled and the pull rope side was 125 and the clutch side was 130 I have a 02 summit 800 w/ 2500 miles on it. It seemed low to me so I pulled the raves and the rings look good I am really supprised. anyway I called my dealer and they said an 800 should be anywere from 120 to 150 on the compression. this seems like a big gap to me. what doo you all think. should I just replace them? and should I use 05 ring or cudney rings?
 

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GSX800HO said:
I would like to know how many Hrs he has on the motor !
Mileage is one thing but hrs running is another.
When you stop on a trail or anywhere you don't always shut down !
So the engine is still running ,so Hrs would be a better number to look at .Just like we do with boats.

Rich
[snapback]295711[/snapback]​
Exactly.....Its alot different when the miles are put on in 25-50 mile increments. I would think Yellowknife rides substantially more than this in one outing. Hours running time may be alot less than someone else who takes 5 years to accumulate the same mileage. I would think he could go 10,000 km's before opening up the top end. I've seen factory built engines go 2-3 times longer, if not more, than rebuilds. As soon as you rebuild, you might as well get ready to get rid of it.....
 

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Crazy Person
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Discussion Starter · #18 ·
GSX800HO said:
I would like to know how many Hrs he has on the motor !

Rich
[snapback]295711[/snapback]​
165 Hours on the motor

duck899 said:
I would think he could go 10,000 km's before opening up the top end. I've seen factory built engines go 2-3 times longer, if not more, than rebuilds. As soon as you rebuild, you might as well get ready to get rid of it.....
[snapback]295792[/snapback]​
I like your thinking duck...I've seen the same things you have. I could ride till it dies, that is an option, and I do think I can safely hit 12,000 km's this year without it dieing on me.

So I gather rebuilds don't last as long as original engine's? What about a completely rebuild engine with new jugs/crank, the works?
 

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I would definitely get qualified compression tester before jumping to any conclusions, doesn't sound right to me, just my opinion. (too much drop off)
 

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Crazy Person
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Discussion Starter · #20 ·
kuziw said:
I would definitely get qualified compression tester before jumping to any conclusions, doesn't sound right to me, just my opinion. (too much drop off)
[snapback]295878[/snapback]​
It is a good tester, my dealer is getting similar numbers. So you think the compression should hold closer/longer throughout the mileage I've done...
 
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