full throttle bog

[PaulAnd]

Last trip out 2010 Assault 900 miles now, only had 1/2 throttle, very bad bog over 1/2 throttle, no warning lights, good fuel other 3 sleds were fine, took to dealer they test it and say its fine... I start checking myself.. ok, pulled exhaust valves and exhaust to check pistons, looks ok, I test compression only have 90psi on both. would it make a difference if the exhaust is still off at this point? I pull throttlebodys and look at intake side of piston and cylinder walls.. no scuffing at all anywhere..is it time for "the fix" or make the dealer recheck it?
and a slightly chipped reed? slight fuel leak from mag lower injector also, and very nasty exhaust valves.. 25:1

 

[PaulAnd]

Going to WY in 3 weeks.. no fix for the Assault yet, I bought another compression gauge, rechecked compression now at 110 both cylinders for me, return to dealer for second time and their gauge shows 140? ok maybe i'm doing something wrong checking compression...?? 4 to 5 hard pulls?? they also told me 10-62 clutch weights are fine for flatland and 8500 rpm is fine?? granted I brought the sled back, with tb's and exhaust off..going to another dealer today hope to post a fix.. very frustrating!

 

[augerin]

Does it pull thru the bog if you pin it? Don't do to much on your own, they will deny warrenty for just about anything.

 

[sled_guy]

Compression gauges read a relative pressure and are dependant on the spring that is in them. So comparing your reading to the dealer's reading is worthless.

If you have good compression between the holes, less than 10% variance, and the machine starts easy they then you don't have compression problems.

sled_guy

 

[PaulAnd]

If I pin it, feels like its going to die out cold or hot only under load.. let off to half throttle and pulls hard again, confirmed good are gas, compression, tps "checked with scope and meter" and tps settings base and final. tb boots not ripped, very small chip in reed but it is sealing, exhaust valves cleaned and no rips in bellows, no scuffing on pistons, 60psi on fuel gauge at idle did couple full throttle pulls on stand, did not drop below 58 psi, holds pressure..no obvious rub throughs, dealer could not find anything wrong... all stock sled no mods except ice scratchers..going to test on street with rubber wheels tape fuel gauge to bars.. wish me luck. then off to another dealer

 

[diamonddave]

It sounds like you're not loading the motor enough with clutch weights. I ran into this same exact problem with a sled earlier this season. Added a little more weight in the clutch and bam, problem gone, different sled. I run 10-62's at 4,000-7,000 ft on 800 CFI's. I would throw in some 10-64's or maybe even 10-66's for the flatland.

I'll bet you a half rack that's what is going on.

 

[PaulAnd]

It sounds like you're not loading the motor enough with clutch weights. I ran into this same exact problem with a sled earlier this season. Added a little more weight in the clutch and bam, problem gone, different sled. I run 10-62's at 4,000-7,000 ft on 800 CFI's. I would throw in some 10-64's or maybe even 10-66's for the flatland.

I'll bet you a half rack that's what is going on.

Yep, I agree clutch weights need to be fixed, gonna leave the 10-62 for ten mile, was hoping to find a problem before going... I guess I could rent a sled if its unrideable.. or buy a new sled If the 2012 m8 was here.. I would miss this forum

 

[PaulAnd]

Pulled the fuel pump and pick-up tube this morning, looks fine.. took it for cold and hot runs down the street, no bogging at all, solid fuel pressure no lower than 58psi. dont know what the hell.. Guess Its going to snowy range, hope there is a good dealer near there...