fresh rebuild high revs?

[steve2wheeler]

just finished rebuilding a 2005 800ho summit (i bought the sled with a blown motor) i rode it the other day and it ran great in the alpine but when i get to lower elevations it feels like the throttle is stiking. I would be riding on the trail and it feels like it is on cruise control and stays at 5000rpm unless i either brake or let tap the throttle. Like i said it runs great above 4000 feet but when i get lower around 2-3000 feet it starts doing this.

Could this be because of the jets and it is running lean? or do i have some other problem?

the throttle cable is fine so that isn't the problem.

 

[winter brew]

Turn your fuel screws out 1/2 turn and see if it helps.

 

[Van Epps]

so whats the trick to reaching the fuel screw between the two carbs? I have been using a long flat head and prying..... got to be a better way.

 

[Van Epps]

feels like the throttle is stiking. I would be riding on the trail and it feels like it is on cruise control and stays at 5000rpm unless i either brake or let tap the throttle.

be cAreful, you may have a intermittent air leak. I was having the exact same thing happen earlier this yr. "Cruise control" as you put it. I found 1 1/2" long rips in each carb boot. (boots had less than 400 miles on them). Don't chance it, check for air leaks closely.

good luck

 

[steve2wheeler]

ok, i will look further. I will pull apart stuff tonight in hopes to find my problem

 

[Tuesday]

be cAreful, you may have a intermittent air leak. I was having the exact same thing happen earlier this yr. "Cruise control" as you put it. I found 1 1/2" long rips in each carb boot. (boots had less than 400 miles on them). Don't chance it, check for air leaks closely.

good luck

2x-check those boots

 

[Danzick]

after you get it all together i would spray some starting fluid around the boots if you dont find any rips. thats what i did but mine didnt pick up any rpms so i knew it wasnt an air leak. good luck

 

[mymitig]

carbs

having the same problem i was told it is the carb sliders and barrels, i can hear them rattling around at idle i looked for leaks and such none found. i find if you give the choke a quick flip it settles down.

 

[steve2wheeler]

well the thing is it idles fine it is only when i am moving it starts to act up. Also when i am in the alpine it runs great. it is only at low elevations and when i am hoving it just sticks at 5000rpm.

 

[Van Epps]

Define "idles fine"?

before I found the holes in my boots it would idle fine (2500) most of the time. When riding it would have the "cruise control" feel you described. when I would come to a stop it would take awhile for the idle to work its way back down to 2500. sometimes I would have to flip to 1/2 choke for a second for it to idle down. I had massive holes in the carb boots. I am lucky it did not burn down again!

I think that when you're not moving, the holes in the boots seal against each other. When accelerating/moving, the motor pull additional air.... AND the movement opened the holes in the boots, letting to much air in and causing the "cruise control" feel. Just my guess

 

[steve2wheeler]

i have it idling at 1500-1700 rpm all the time it just when i am moving it does that "cruise control feel" and only at low elevations.

The thing that draws me away from it being the reed boots is....
1. I have checked and there is nothing wrong with them (no rips or cracks)
2. If they were ripped would elevation changes have no effect on the problem?

I don't no what jets are in it and i was wondering that if the sled was set up to ride at high elevations when i got to lower elevations would it cause the sled to run more lean and causing this problem?

 

[bri74]

My motor had done the same thing, quick flip of the choke it would idle down, Looked my boots over and over finding nothing, well shortly after that the motor ate the mag side cyl. I couldnt find anything wrong with the boots untill I pulled them off the cylinders and pushed on them from the inside out. 1.5 inch crack from top to bottom. This has been a huge problem I wouldnt rule it out with out checking for sure.

Main jets effect 3/4 to WOT position. Check the pilots

 

[8rmk00]

if it were the carb boots or crank seal would it show a lean condition on the plugs?

 

[weetee]

if it were the carb boots or crank seal would it show a lean condition on the plugs?

Good question. Anybody know?

 

[Van Epps]

It would only show on the plugs if you can recreate the "cruise control" feel long enough to get a plug reading, then chop the motor with throttle left in same position. (just like any other plug check run)

 

[steve2wheeler]

thanks for all the help but i haven't had the time lately to work on the sled so i will let you know what happens when i get around to working on it