08 700 CFI just a dog

[Brad62]

From reading the threads guys are having trouble with a few of these cleanfires being real doggy. I happen to have one. And it's getting real frustrating. When it was put to sleep for the summer it worked awsome. When it was put back to work it was straight to Mcbride in Dec and the first day it seemed to work alright but as the week went on it wouldn't hold its RPM's then I couldn't get them past 7900. I thought it was the snow (heavy and deep) also I was trying out some MTX weights, thought maybe to heavy. So made the best of it and brought it home and tried to do some tuning. I've tried just about everything but cannot get it above 8000 on the flat with any weight setup that's within reason. I guess I could try 56's or 54's in it on the prairies but my wife's 500 could swing those weights!!! The compresion is up, clutch's are up to snuff, ex valves are clean, track is loose and rolls easy. IT"S got me stumped. I guess all I really want to know is if some have worked this out, and what you did to get it back in shape.

TIA For any help

 

[Dragon mod]

what are you running for weights and gears? We geared my wifes down one size and put reeds and a pipe on it and it screams no problems

 

[Brad62]

I've tried 10-60 and 10-64 with no change in RPM's on the flat at home here. I was running 62g MTX weights 3g in outside hole with a blue/yellow spring at 6000- 8000. Ran the same there. couldn't hold it's RPM. It would crawl up to 7900/8000 and when it got loaded up it would lose 200 - 300 RPM. Since then I've changed out the secondary spring as it seemed to be a little weak. Haven't had much chance to play with it. With the nice weather I'm trying to catch up on the stuff I didn't do when it was 40 below.

 

[08DRAGON]

Had same problem honestly it was the gas from petro canada went back to shell premiun and the problem went away.

 

[OnlyPolaris]

i was going to say, could be old gas in the system still from last year.

 

[xxx]

try a set of ngk plugs part # BPR9EIX

 

[zgrizz]

Cant say Ive had the problem with my 700 yet, in fact just the opposite, trying to bring the RPM's down, Basically have the same set up as you, changed gearing, primary, and am running 10-60 weights and was revin at 8500 last weekend at the 6000'-8000' alt.
I drain my tank in the spring put fresh gas in and fire it up once a month. I would have to say bad gas! And I have heard that petro Canada gas has been causing problems.
Let us know what you find GOOD LUCK wish I could be more help

 

[Keng]

i know mine was boggin.. got pissed on a long ride and decided to throw in some injector cleaner.. about 45 min later.. the sled just woke right up. think its a problem with the injectors getting clogged could be wrong. but worked for me.

 

[Brad62]

Not a bad Idea Keng. I have done some tuning and tried a black green primary and heavier secondary spring and it seems to be holding its R's now. It still bugs me that it worked so well then just went south. I do the same over the summer iI usually start it every month or so. With the old carb sleds you could fog them then drain the bowls and I never had a problem with plugged pilots or mains. Woke them up in the fall with some fresh fuel and away you went. I still feel there is something wrong but just can't see it. Maybe the injector cleaner will do the trick. Thanks.

 

[sledhead2481]

i know mine was boggin.. got pissed on a long ride and decided to throw in some injector cleaner.. about 45 min later.. the sled just woke right up. think its a problem with the injectors getting clogged could be wrong. but worked for me.

what kind of injector cleaner. have you had any problems since

 

[sledneck_03]

Try changing or cleaning your fuel filter, and also when did you clean your ves valves? Mine were clean but one day out of no where same problems and we thought it was the filter because of same reported symptoms and a filter fixed it. Then it was that one of my exhaust valve bellows was cracked, apparently happens all the time.

 

[bubba700]

another thing that hasn't been mention it that when the belts get worn or polished on these sleds it wont hold the R's , Thought that it would over rev if the belt was worn and slipping but it happened to me begining of the year, Was struggling to even pull 8k rpm at the same elevation that I would pull 8150 or 82 last season. Put a new belt on and bam right back to 82, rode it a bit, swapped the prob belt back on and again lost r's. Swapped it out and its ran like a champ since. Might try this out.

 

[Brad62]

Try changing or cleaning your fuel filter, and also when did you clean your ves valves? Mine were clean but one day out of no where same problems and we thought it was the filter because of same reported symptoms and a filter fixed it. Then it was that one of my exhaust valve bellows was cracked, apparently happens all the time.

I Have tried a new filter and had no luck with that either. Cleaned the ex valves just like I used do with my 02 700. I did have a bellows crack on that sled and it kind of did the same thing. I actually felt and heard it go when I was climbing a hill at Mcbride. but this feels different. And I checked the bellows when I cleaned the valves.

Thanks for all the replies there's great help on this forum.

 

[timbo]

did you check pistons when you had ex valves out.check for scoring on ex side,might be starting to take a piston down.

 

[Keng]

so been a week so far and the sled is running top notch like the day i got it.. and for those wondering i used to kleen flo injector cleaner silver bottle.

 

[fargineyesore]

Dealer's doing a reflash on my ECU.