:confused:my gas gas pro sounds like shit runs like shit ,a piston chirping sound is surfacing,id like to rule out rings,the bike does not smoke excessively, but is not running as crisp as it should.91 octane fuel at 80:1 in lieu of 87 at 100:1 thinking it was bad gas,im thinking air screw or needle? has tons of compression .help 2-ply or any others

Start simple. Change your fuel, drain the carb, replace the spark plug. If that does not fix your problem, flush out your pilot jet, mid range might be lean causing knock. If that is all fine and still runs poorly, check to make sure your flywheel did not shear the key. Also, make sure you do not have an air leak between the carb and cylinder. Hope your fix is simple and found quickly.

Start with the basics....new spark plug, drain the float bowl, may even want to go as far as draining the tank. Pull the pilot and main jets out and make sure they're clear and you can see light through the hole drilled through them. Check that the air filter is reasonably clean and fitted properly. You mention a chirping sound.....possible air leak through the intake manifold? Broken reed? Cylinder head or base gasket leak?

Be patient, it's there, you just have to find it......

new plug,pulled carb blew out main and pilot,clean air filter always.didnt check the reeds though?im thinking the worst here ,top end,but it dont blow out smoke! its lean .motul 800 @80:1 i usually run 100:1 thinking that would help,the intake seal is tight.no sign of cylinder and head leaks,bolts are tight

thanks for the tips guys very legitimate,but.....O.M.G!!!!!the problem was the spark arrestor cap that they sell here was completely clogged couldnt even see through it, i dont know what made me check it but the power is off the charts.this is a lesson learned for me and will always be on my maintainance list at every air filter cleaning,and you guys as well.??? when repacking the silencer do i drill out the rivets on the end cap or go from the other end?

FESTER said:

I was wondering about this also.

As an observation, I run 100 octane aviation fuel at 80:1. 91 makes it knock. Expensive but that burnt avgas smells sooo good.

John

Those arent rivets at both ends. Look closely.

mine gots rivets on the endcap,any ways wrapped a layer aroud the baffle and tied thin wire around it put the baffle back in and while keeping it centered stuffed the hell out of it sounds great.

My 03 280 Pro runs O.K. on 93 octane pump gas as long as it's fresh but if it sits for more than 2 weeks it runs like crap. I can't imagine trying to run it on 91 or less. It runs much better on higher octane fuel. GasGas recomends 95 or higher.

As for the rivets, yes, drill them out. I can't really see any other way to get in there, short of cutting a trap door.

FESTER said:

I was just getting ready to suggest that... I've been seeing that problem on a few bikes lately.. Also a problem shortly after repacking your muffler, but not until you've done a few full power romps. :thumbsup:

You drill out the rivets. You can replace them with screws if you don't have or want the rivets.

CRM114 said:

I mix 3 gallons of 100/130 AVGAS with 2 gallons of unleaded Premium 92 octane pump gas. I also add an oil based fuel stabilizer that I get from the Stihl Chainsaw dealer. Then I keep as much gas as I can in the 7 aluminum fuel bottles that I've acquired over the years. They don't vent and can handle the pressures so the gas stays fresh in them. I've heard that some of the key octane ingredients can leach out through the plastic in many gas cans.

I'm using the Amzoil 100:1 smokeless oil at ratios of 90:1. It shows signs of being too strong with oil at the exhaust tip but that's OK by me, I'll clean it when I do my regular Spark Arrestor cleaning.

Keep in mind that when you increase the oil in the mix, you are making the fuel/air mix more lean. The oil doesn't count in the combustion equation.

And keep in mind that air cooled bikes need more oil and the older water cooled Gas Gas bikes before the Pro Model use a mix of 80:1 or richer. Their main crank bearings are lubed by the oil in the gas. The new Pro engine is pressure lubed at the main bearings by your transmission oil. Good reason to change it often.

Maybe you have a small bird stuck in your exhaust, such as a Wren.

your a funny guy there tarzan,but theres no other way to describe the sound on a freaken computah,it was the sparky, lesson learned

Im just messin around

me too

FESTER said:

Oh, OK, NOT a Wren.. I know Sparky... Makes a lot of noise too. :smirk:

oh! you too chisel chest?,ok i see how it is,how bout a freaken spotted owl.

Dude you cant run 91 octane gas in that bike. I wouldnt. Get good fuel like 110 VP and your bike will run much better!!!!!:naughty: Just my opinion.

im with you.point well taken