i got a friend whose got a 98 summit x 670...last year it developed the problem that whenever he pins 'er it goes and then bogs out until he hits a lower rpm and lets off gas....any suggestions? he went over everything possible, pulled apart carbs...so did the dealer....tried every trick they know...they're gunna check the air pump soon....sound familiar to anyone?
bogging on a 98 summit x at wot
- Thread starter 98-700RMK
- Start date
A couple quick things to check. where the fuel lines go into the carbs, make shure there are not some white plastic screens that are left in those nipples if there is remove them. also find the hose that is a vent for the DPM ( it should be a line that connects to the dpm and just runs down connecting to nothing ) remove the line and there is a small jet that screws into the dpm rail, take a small flat blade screwdriver and make shure the jet isnt loose are fallen out and the reinstall the line this will make it run rich if it fell out. It sounds like he is starving for fuel you should probably check the fuel pump and the pickup in the gas tank as well as the vent line to the tank.
I had the same problem and it ended up being the DPM had failed. It ran great down low and when wide open would just bog until I let off. I unplugged the DPM took the two screws out of the throats and left all the hoses unhooked on the carbs. Bought some main jets and started leaning it out on my way from 5000' to 9500'. Got it to be nice and crisp at elevation then I installed some dial a jets with the snorkel kit. That was 14 trouble free rides ago and the sled runs excellent. Unhooking that DPM and deleting the oil injection and running klotz r-50 with lots of klotz octane boost was the best thing I ever did to my 670x
Sounds like the computer to me, my 99 summit did the same thing.
If the sled runs good to about 3500 to 4000 RPM and then the motor cuts out until it drops below 3500 RPM it is the computer.
Find another 98 or 99 summit and swap out the computer to see if it fixes the problem.
If the sled runs good to about 3500 to 4000 RPM and then the motor cuts out until it drops below 3500 RPM it is the computer.
Find another 98 or 99 summit and swap out the computer to see if it fixes the problem.
remove the spark plug caps, cut a 1/4 in off the wires and replace the caps with the plastic caps. And gap your plugs to spec.
YEP! And use only resistor plugs. A little dielectric silicone gel in the caps helps with the '98X also, any arcing between the caps and plugs will raise hell with the MPEM. If there is alot of soot in the caps and on the plug porcelain, this could very well be the whole problem.
S
snengineer
Well-known member
Bad Gas? maybe your jets are plugged up with crap? this is a common problem if the sled has been sitting for long.
