i just purchased a 98 670 and it is bogging on hill climbs but runs at full power on the flats. does anyone have a starting point for me to investigate? the hac is hooked up correctly and i installed slp filter fabric on the intake foam. any advise would be great thanks
670 summit bogging
- Thread starter hopsmalone
- Start date
I too have a 670 summit, i have had it for 9 years. The biggest problem i had when climing was the tension of the secondary. You might need to load it a little tighter, or change helix. I have purchased another secondary on this forum and set it up for higher elevations and just switch when i go from the prairies to the peaks. It is simple to try alittle more preload and if that does it you can tweak from there.
Thanks for the advice ill get on that see what happens hopefully it will help!
Do you know what main jet you're running? What altitude? What number is your clutch set at? What rpm do you max at on the flats?
Get rid of the SLP pre-filter and the stock foam in the airbox and see what that does. I'm curious if you are not moveing fast enough to feed air through the pre-filter and foam on a climb. The other thing to check is the fuel pick-up inside the tank. Make sure the line goes through the tank and is still attached inside the tank enough to go to the rear of the tank. I had one that would do the same thing. When the tank got low, the gas would slosh to the rear of the tank on a climb and the fuel pick-up was sucking air.
I have already tried pulling the foam in the air box i was running way to lean almost to the point of explosion so i threw that back in im normally riding above 9000 and on the flats im running 7300 rpms my clutch is set on 3 and for some reason it almost seems better with less gas in the tank i havent figured that out forsure yet ill keep taking your advice thanks for all the input
7300 is not nearly enough rpm. I believe you should be running 8000-8200, at least that is what my 99 runs at 10,000'. My TRA is set on 5 and I'm not 100% sure what ramps are in the clutch other than to say it was my dealers standard setup for 10,000'
My 95 670 runs at 7800 rpm, stock except for main jets. Went from 420 to 380. Before rejetting it would bog down in powder and on hills. After, no problem.
I do know the dealer jetted my 99 down from 350 to 320 on the main jets. This sled has never missed a beat and has passed the 4000 mile mark. Still on the same hifaxes and carbides as well.
Anyone want to buy some carbides? I bought some about 4 years ago but they are still hanging in my garage because I bought a newer machine 2 years ago.
Jim
My 95 670 runs at 7800 rpm, stock except for main jets. Went from 420 to 380. Before rejetting it would bog down in powder and on hills. After, no problem.
I do know the dealer jetted my 99 down from 350 to 320 on the main jets. This sled has never missed a beat and has passed the 4000 mile mark. Still on the same hifaxes and carbides as well.
Anyone want to buy some carbides? I bought some about 4 years ago but they are still hanging in my garage because I bought a newer machine 2 years ago.
Jim
Check the hac to see if it is in spec.
Pull the hac off an look in the tube and check with a micrometer to see if the pin insideit is within 3-7 mm. to the end of the tube if not it is probably bad. I have changed a few throught the years and that is what usually happens after a few years. The hac has developed a leak in the diaphram and the pin has recessed and lost it's calibration.
ps the rpm should be around 7950 max on a 95-98 with the hac system
Pull the hac off an look in the tube and check with a micrometer to see if the pin insideit is within 3-7 mm. to the end of the tube if not it is probably bad. I have changed a few throught the years and that is what usually happens after a few years. The hac has developed a leak in the diaphram and the pin has recessed and lost it's calibration.
ps the rpm should be around 7950 max on a 95-98 with the hac system
Last edited:
Smokymtn 98 Summit Didnt Have Hac
They Had (dpm)
They Had (dpm)
Similar threads
