Quad boggin down

[maximus1029]

Our 09 90 has been bogging down. Started last year, trackside assistance though maybe pilot was too fat adn changed the jets, which worked for awhile. Started again two weeks ago. Real intermittant. I changed the jets back to stock, I cleaned the carb, changed the fuel..and I don't know what else. It is becoming very frustrating. The problem is so inconsitant. The frist moto today was fine and the second it happend, just as before. He kind of figure out if he didn't push full throttle he could make it around, and still finished. On long runs it would wind up fine then at full throttle would bog down and sound like there was no fuel. I'm lost. We were thinking maybe the float was sticking (when I took it apart and put it back together, the brass nipple/needle (whatever it is) slides up in between the float, and it seems like that might be catching.

Any suggestions would be appreciated

[chris p.]

our drr was doing something similar and it turned out to be the fuel shutoff went bad. eliminated it and it ran mint.:D

[mmsoup]

Just a guess but I would bet money you have an air leak or you are jetted lean


Put it on a stand and hammer it, if it climbs up and bogs or climbs up and misses slightly that would do it for me.

Do you have a leak down tester? Check closely around the intake area and the cylinder base typically in that order.

[maximus1029]

First thought was lean jetting, changed it back to stock (fat)..not it. Don't have a leak down tester but at the suggestion of Les at G-force, check the crank seal behind the water pump and no sign of leakage. Others suggested a ground problem, I'm not great with motor stuff so I'm kinda walking blind. Couldn't find where the ground mounted to frame but noticed the ground attachment to the Pro-Armor kill switch I installed was loose and the wire came right out. I am of mind it is some kind of electrical problem due to the problem being so inconsitant. It usually happens after a hard jolt. I'm crossing my fingers.

[mmsoup]

Leak down tester will find leaks you can't

You can find instructions on line to build one. We made ours out of a blood pressure cuff. (Need the bulb and the gauge) we devised an intake adaptor out of PVC parts (Fits into intake boot) and used a freeze plug to seal the exhaust. Works like a charm.

Generallly you have the biggest leaks around the base of the intake. What Les suggested makes very good sense. Our problem started with the right crank seal and we stumbled forward from there.

Another thing you could do in a pinch would be to start the motor and spray ether based starting fluid around the intake base and the cylinder base. Only problem with that is it isn't foolproof. Hold the throtlle open as much as possible and spray the areas. If the motor races or stumbles you have a leak

Have you checked compression on the top end? May have a ring issue when the motor gets hot. How many hours on it? We have been running these little boogers for 4 years now and have been right there on more than one occasion and it is typically Leak or Ring. The only other thing that occurs is the Stator going bad.

[QuadRacer041]

Having a simalar problem with ours. I noticed after I bought it that the previous owner used sheet metal screws where the exhaust flage bolts to the cylinder and the gasket was blown out. I got the right bolts and i'm waiting on a new gasket. Can the blown out gasket cause a loss of power up top?????

[maximus1029]

Going through the bike with Les (from G-Force)on the phone, the bike died and would not start! Had spark, reeds ok, everything seemed okay. Les has me check the crankseal, and I notice the wire coming off of the stator is barely hanging on. Have a new one on the way, so we see if that is the problem (everyone has a feeling it might be).


From some of th advice I have gotten -
For you, replace the gasket, check the reeds, check to see if crankseal is leaking (pull off water pump cover and look for fluids)

Is is losing power while riding, or on stand too. If it is just while riding, probably need new clutch set up.

Add a couple of grounds.

If still not working, might be stator?

Good luck

[redonkulousruntsracing]

My sons 50 gave me fits all season long, it had no power on the top end. I tried clutching, jetting, carb swaps, cylinder swaps, new top ends, crank seals..... spent a fortune and embarrassed my son at many races with a gutless quad. All of this because of a $20 coil. Would have never thought a coil would have caused those symptoms, but that was it. Put a new coil on and holy crap, the thing flew. Runs like a champ now, I only wish I would have tried that back in May when my problems started, would have saved me a lot of $$$ and my sanity.