Summit 800 help

[sledr4life]

Between us we have 3 800 summits and just came back from a very frustrating trip out west. 2 are 2001 and 1-2002

one of the 01's and the 02 ran fine. The other 01 was just recently rebuilt and had about 40 miles on it back in ND and ran fine.

once out west we had to drop the main jets from 500's to 470's due to a severe burble or loading up. it still ran pourly, but managed to make shift rpm on occasion. We had hollow pins empty, and had to change to a 130-350 spring to get full shift and the clickers are on 6

We tried switching out the mpem and dpm from the other 01, but it did not make a difference. We also resealed the dpm ends and installed new hoses.

It does have an aftermarket can on it that we know nothing about and possibly vforce reeds, however can not confirm this. we have pulled them out and the petals are in good shape.

If anyone has some suggestions as to what else we may have missed that would be great. We are really scratching our head as to what the problem is. why it makes power here and not out west just does not make sense.

Thanks,
m

 

[go high fast]

Pot in two of TBD SLP florites in the dask and drop the needle I spot I'd you have the adjustable needles. Biggest and best change would be to gear down significantly and go with. Team roller and a straight low angle helix. Put clicmers back to 3.

 

[cubby]

Pot in two of TBD SLP florites in the dask and drop the needle I spot I'd you have the adjustable needles. Biggest and best change would be to gear down significantly and go with. Team roller and a straight low angle helix. Put clicmers back to 3.

X2 what he said only with spell check on LOL!!

Biggest thing with those sleds is air flow.

 

[sledr4life]

Thanks, we already have the flowrites in the dash.

I will check the needle again, but if memory serves it is not adjustable.

In comparing the reeds to the other sleds we noticed that there is a large spacer between the reeds and cylinders. the other two 800's do not have this???

m

 

[bohrer54]

have you tried switching the carbs with one of the 800's that run good?

I know my zx as well as some others had trouble with lean mid range due to improper venturi height. Mine ran great until i put vforces, a can, fixed the y-pipe and crank seals, then i could not get the midrange to work at all, finally switched to 05 carbs, works great now.

Might be something to look at.

 

[winter brew]

Compression test?
I would go back to 490 or 500s. I doubt its a jetting issue since that is stock jetting. I would look towards general engine condition. How many miles on them? They had issues with flaking rings and reed boot delamination.

 

[sledr4life]

Will do the compression test. what should it be at 900'?

The motor was fresh, new seals, pistons/rings and only had 40 miles on it prior to going to the mountains. it ran great in ND.

It does have a can and we thought it had vforce reeds, but they dont look like the vforce on the other sled.

 

[winter brew]

look for 130 + lbs.

 

[BOOFIT]

Do the plugs look rich when at altitude? If yes then I would say either DPM or compression.

 

[sledr4life]

tore is down last night. glad we did, but still not sure why the loss of power.

mag side piston had a cracked skirt on the carb side dead center. there is actually a mark on the inside of the piston where is hit something. there is no mark on the crank or connecting rod, so really scratching my head with that. There are no marks on the under side of the head.

We checked clearances and found that one cylinder is .005 larger than the other.

The PTO side rave guillotine is shiny as though something has been rubbing against it, but this is the smaller cylinder.Also looks like the nicasil coating is worn off at the bottom on exhaust side. not sure if these are related.


There is an 8 hole base gasket which I am sure lead to some of the missing compression.

We had checked these in the past after rebuilding and dont ever recall seeing 130 lbs. maybe 125 and both cylinders are close in readings. last year we did a compression test at 8100' on two other 800s that run fine. one had 95 and the other had 105.

Since the cylinders are as is we are now considering one of Kelseys big bore kits. If anyone has some input on this, that would be great.

m