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Discussion Starter · #1 ·
Hi all.
I bought this sled last year. The engine was replaced with a new crate 800ho shortly before I bought it. So this engine is very fresh still. From day one is has not reved past around 7500rpm. I had tried stock clutch setup. Cudney kit. Multiple helix's springs and pin weight combination. Compression is around 150 psi. New sliding half and spring cup in primary. Completely new rer secondary. Confirmed jetting. Carb boots good. Raves cleaned. New plug caps. New plugs. Set oil pump/oil consumption correct. Can't see any cracks or holes in ypipe. For the last 500 plus kms I have been running the SLP kit (pipe/muffler/0-3000ft head at .052 squish/ported cylinders). Running super strong low and mid but still only reving to 7500. Pin weight does not change it.

Any ideas??
 

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Discussion Starter · #5 ·
1)I will look close at RAVE operation.
2)Yes it may be the tach I guess. Not sure how to determine that for sure.
3)Jetting. Remember this is a old problem. In stock form and now with SLP parts. In stock form it had 380 mains. Stock needle ending in 7-58 I believe. 17.5 pilot. 1.5 out on fuel screw. With SLP I started at 470 mains per their recommendations for sea level and -40 and have slowly worked my way down on mains to 400's by diagnosis of symptoms and plug chops. Had richened the pilot to 25 but too rich and gurgle down low. Back to 17.5 pilot and 2 turns out on fuel screws. Slight hanging idle so may go to 20s. Stock needle. Mid range has always been clean. May try .020 shim to safety sake. I could not get over 7000 with the super rich mains but as I have been coming down I'm back to 7500 like before. Im quite confident this is not a jetting problem.

Question. Reading over others with similar problems one guy mentioned something about the tank vent lines being plugged and something on the frame around the oil resovior that was part of the venting system.. Yesterday I did notice after running it some fuel came out the vent line behind the secondary clutch. I opened the fuel cap and it stopped. It was not a lot of fuel but just makes me wonder. I guess there is a screen on line end in tank that I should try to get to. But with too rich mains causing even lower rpm I'm not sure fuel starvation could be the issue.
 

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Discussion Starter · #6 ·
Could this have anything to do with the ECU or whatever mapping system the 2003 used?
 

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2003 has about 3ft of small gas tank vent hose wrapped around the center pyramid support

Make sure its not pinched anywere,,you can pull it off below the gas cap under the console to test ride it with less than a full tank
 

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Make sure the little carb vent hoses are venting also,,non DPM they go to a T and bkgger hose to the airbox to breathe
 

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Discussion Starter · #9 ·
1) the rave valves are moving in unison but are starting to open just over 4000rpm. Is that normal?
2) gas tank vent line is allowing air through when I blow in tank. I took small line off at valve under console and it also blows fine there. I would sure like to know what the point is of going from full size fuel line reduced to 3 ft of primer line?? The carb vent lines t at a union on rail on carbs and fuel line size line goes to my side panel. I can take it off at panel and blow or suck and air moves and I can sense fuel on other end. So I assume it is free as well.

Could the mpem be an issue here?
 

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Coolant temp sensor maybe as Jeff 800 suggest I had that issue once myself . I dont think this year does but does this sled have a throttle position sensor on carb ? If so may it may need reset .

Sent from my iPhone using Tapatalk
 

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Discussion Starter · #14 ·
-Track tension good.
- Not sure how to test coolant sensor?? Not even sure if my 2003 is wired the same as yours to cause my symptoms if it was bad? I think there are four wires that come out of the sensor. Two go to the mpem box and the other two into main wire harness and I assume to spedo. The sensor does light up when hot and the temp light comes on at startup then shuts off like the rest on spedo.
- There are no electronic wires on my carbs so I assume no throttle position sensor.
- I need to get my hands on a quality ditital tach to verify this is not just a problem with my tach. Any recommendations?

Thanks for the suggestions!
 

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That sled does not have the carb position sensor. Yes there where 4 wires coming out of the sensor.2 wires tie into the same connector as the DPM solenoid and the other 2 head up under the cowl, I think they go to the over temp light' did not follow them. you can not get the sensors new anymore, have to look for used. I used 1 out of a 500 SS. You will need to check as yours is a 03.
 

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Discussion Starter · #16 ·
How did you know your temp sensor was bad? What symptoms and how did you verify the issue was the sensor? If ohm tester how did you test it? Like I said mine does light up dash light when hot and goes back off when cools down. Thanks.
 

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I didn't know the sensor was bad. I was desperate, sick of tacking only 7500 RPM's , I had gone through and rebuilt and tested my clutches, raves, DPM and its hoses, Carbs, Replaced air temp sensor, check bearing, compression check, clutch weight, clicker move, there must be more. After reading the service manual and it said if any of the sensors connected to the computer where bad or disconnected it would go into a limp mode. The CTS was the only thing I had not touch and I was At my sugarhouse and had no way of testing it and had bought a used sensor, so I changed it out and was back to 8000 .

You will need to check manual or do a search for the testing

Where the h*** did the line come from
 

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Discussion Starter · #18 ·
Nice line eh! What year is/was your 800ho? Mine is a 2003 and had read it does not have a limp mode. Maybe incorrect information. Do you know? I also have no dpm. Have you watched through the side opening of your raves to see what rpm they start opening? Mine are tightened right down but starting to open as low as 4000 rpm with these slp parts on now. It's fine for trail riding but if I hammer it from dead stop like in snow drags it drops rpm down around 6500 for a couple seconds off the line then picks back up.
 

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Mine is a 04, not shore on the 03 as I have the service and race manual for the 04. Not sure when my opens exactly but is around 6500-6700 RPM, I read in the race manual if they open to early they can cause a bog,.
 

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The raves are supposed to open at over 6000 rpms

4000 is way to soon to make engine run best and reach max rpms?

Put the spring back to stock if you changed a setting

Try the stock exhaust,,most aftermarket stuff make them slower
 
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