2010 Gas Gas Six Days 300 (Help)
 

This is my first Gas Gas and it hasn't been the most favorable experience. I purchased the bike in April of this year and here is what happened so far with the bike.

First the bike was diffucult to start and seemed as though the jetting was too rich. I checked the carb set-up and this is what I found.

178 main
42 pilot
N1EF Needle second position from the top
air screw 1.5 turns out
riding area 1500-2000 feet
88-95 degrees outside

The bike ran horrible just above half throttle as if it were loading up, the side case (clutch side) had an extreme amount of heat. Within a day or so a 2.5 inch hole cut through the clutch cover. One of the hex head bolts either was not tightened appropriately during assembly or backed out. It was covered by warranty

Next the choke mounted on the bar stuck opened causing a rich running bike and I replaced that with a manual one.

I pruchased numerous jets and kits from JD jetting and L T racing nothing seemed to work

The jetting problem or irregular running bike continued, I took the bike to a Gas Gas Dealer to help me trouble shoot the poor performance. We replace the following parts and the bike still does not run any better.


New carb
New CDI
New Coil
New Voltage regulater
New stator and wiring harnes
New dual mapping switch
New Exhaust and muffler
New Reeds and v-force intake
Verified compression and leak down test

We verified the power valve was working and not sticking. Nothing seems to change the iratic running. We also had a new 2010 300 and could campare the difference between the two bikes. My bike the six days model ran so poorly the shop technician was embarrassed.


What should I do next, I am really dissapointed with the bike but the customer service from Go-Fasters and the dealer have been incredible. I have been riding all my life and nothing like this has ever happened with a bike I have owned.

Airbox restriction? Something in the airboot restricting air flow? (It's been known to happen). Has anyone looked through the carb boot to see the path is clear?


I know GG dyno tests each engine before it goes out. However, that is before it is in the bike. If something made it into the airbox, you'd have a rich condition

Do we know that the timing is set correctly, and advancing per spec (whatever that spec might be)?

Have we pulled the engine apart?

Were the new parts off of the other 300 in the dealer, or off-the-shelf?

Given the ease with which the motor can be disassembled, if it were me, I'd pull it apart (if the quality of the parts already swapped can be verified). Or, just swap motors with the good 300, then start putting your old parts on and and see where that leads you.

Good luck.

blitz

Measure the squish band. If that is really "loose" I believe that would make the bike hard to jet and rich.

Check that your head gasket is sealing properly. If the 'O' rings are pinched, they can let coolant into the cylinder and the bike will run like crap. All it takes is a few drops of coolant to have an effect.

Is your powervalve moving when you rev the engine ?

Six days
 

There is no obstruction in the airbox

There is no coolant in the combustion chamber

The dealer is waiting for authorization to disassemble the motor for inspection

All of the parts were new nothing used

I can't understand how this could happen to a new bike. I have a 2008 250 xc KTM that has 2000 miles been raced in 39 events and it runs circles around the bike. Two Gas Gas mechanics can't find the issue along with Go Fasters.

2010 Gas Gas Six Days
 

Even though I am frustrated at the moment I truly believe Gas Gas will resolve the issue to my satisfaction, and the reason I am saying this is because I believe they care about the customer. I will keep everyone posted as this situation continues

Check or replace the rubber plug cap for the spark plug that screws onto the HT lead. That may be faulty.

Get them to replace the bike.This is a lemon & you will never have enough confidence in the bike to truely enjoy it.

Sorry to hear about your problems, this is most unusual.

So far all things mentioned have been positively ruled out? Its a simple 2-stroke so not much is left before going back and looking twice. I'll take a shot and say its a small leak the leak down test did not show. A very small amount of coolant or trans oil being drawn into the cases. Base gasket, case gasket, head oring, casting porosity. If its something rare like that then I agree I would want at least a new motor.

A quick but crude test might be to temporarily replace the coolant with a waterless type, or straight polypro glycol like Sierra (cheaper). The system pressure will be very little due to the high boiling point, so if there is a small coolant leak things should improve as less coolant will be forced into the cases. While not a definative test it might point you in the right direction.

Just a thought:
You seem to have replaced every component likely to cause such a problem, but what's in your fuel tank?

Are you sure the gas and premix is ok? what fuel do you use? Lots of additives of ethylene? Try use premium fuel with less additive.