Gas Gas ec 2006 1st gear problems
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barossi73
Gold Level Site Supporter
Are you sure it was 'off' and not 'reserve'?
Some petcock use the arm to mark position,some are opposite.look close at petcock arm,is there an arrow on it on either end of arm?
If it was actually 'off' it should only run for maybe 30sec to 1min then die.
If it was actually 'res' then you may have contaminant in tank that slowly clogs petcock intake and strangles fuel supply.
Switching to res temporarily gives it a clear pickup,but it would also clog given time.when the bike is off, the vacuum subsides and releases sediment from intake.
Remove tank,sluice out.
Remove petcock,blow through from carb end with tap in both main and res positions.check intake visually for damage
Some petcock use the arm to mark position,some are opposite.look close at petcock arm,is there an arrow on it on either end of arm?
If it was actually 'off' it should only run for maybe 30sec to 1min then die.
If it was actually 'res' then you may have contaminant in tank that slowly clogs petcock intake and strangles fuel supply.
Switching to res temporarily gives it a clear pickup,but it would also clog given time.when the bike is off, the vacuum subsides and releases sediment from intake.
Remove tank,sluice out.
Remove petcock,blow through from carb end with tap in both main and res positions.check intake visually for damage
Funnily enough I realized today I have been running the tank on reserve since day 1 and today I ran it on ON and then reserve, same issue. When I turn it off it runs for like 2-3 minutes and then cuts out.
pscook
Platinum Level Site Supporter
If it runs noticeably better when it's almost out of fuel, it sounds like a stuck or otherwise mis-adjusted float.
Do you know the exact name of my carb? I think I'll try buying one of them just to be sure because I'm going to order a 175 main too. Although I think it's OK because the needle part that gets "pressed" works fine when I used something thin to press it down it springs back up nicely.
Jakobi
Super Moderator
There are more than a handful of variations and names getting around. Some have a threaded cap, others have the flat cap retained by 2 screws. Some have deep bowls, some have shallow bowls. Some have shorter bodies. The AS series I believe is in relation to the fins in the intake and come in series 1 and 2. Some have a throttle position sensor (and/or powerjet). Some have a leak jet for the choke circuit as well. The 36/38 relates to the throat size.
It doesn't really matter which particular model you have though, as the jets and needle valve should be the same across. The easiest thing is pick any late model 2T (Yamaha/KTM/Husberg/Beta) and order yourself the required OEM Keihin parts.
Don't waste your time with aftermarket options. Keihin is the go.
It doesn't really matter which particular model you have though, as the jets and needle valve should be the same across. The easiest thing is pick any late model 2T (Yamaha/KTM/Husberg/Beta) and order yourself the required OEM Keihin parts.
Don't waste your time with aftermarket options. Keihin is the go.
barossi73
Gold Level Site Supporter
Did you put a fresh viton in carb and check the amount of piston visible thru exh port to confirm your base gasket thickness yet?
Id do this first before messing with ignition timing,the fact you said it ran well for 15min before playin up suggests to me its more likely not ignition issue
Id do this first before messing with ignition timing,the fact you said it ran well for 15min before playin up suggests to me its more likely not ignition issue
I googled about the viton and people were saying to check the needle that gets "pressed" by the float for wear and mine seems fine so no I didn't bother replacing it however I am looking to get a replacement carb as a tester.
When do I check piston? When it's at tdc or? Would it still run good for 30minutes or so? Also it splutters at top end, I thought if my compression/gaskets were messed up then it would lose power not splutter?
Jacob 'Berg
Member
You may not notice the viton needle is worn unless you have it next to a new one for comparison. It does not take much wear to cause an issue.
Piston should be at bottom dead center.
Okay I will check out the piston tomorrow, what sort of measurements am I looking for? Does a guide exist?
Jakobi
Super Moderator
Compare the leading edge of the piston with the floor of the exhaust port at bottom dead centre.
If they are flush you're port timing will favour top end. With less base gaskets the piston starts to sit higher and you'll end with a power curve that favours bottom end. Around .5mm above is pretty reasonable for an enduro machine but moving beyond .7mm you start to see the top end performance suffer.
Again, this is only something to check.
Given that you said the bike ran well for a period of time and now doesn't, and that it appears to be running rich at the top end, and also you're powervalve issues, I'd be very carefully going back through the PV assembly, the air intake and exhaust, replacing a plug, replacing the fuel, and thorougly cleaning and inspecting the carb. Blow out/jets and fuel passages, check the needle is secured in the slide, collar and spring, check float levels! Throw an inline filter between the tank and carb too.
Work methodically.
If they are flush you're port timing will favour top end. With less base gaskets the piston starts to sit higher and you'll end with a power curve that favours bottom end. Around .5mm above is pretty reasonable for an enduro machine but moving beyond .7mm you start to see the top end performance suffer.
Again, this is only something to check.
Given that you said the bike ran well for a period of time and now doesn't, and that it appears to be running rich at the top end, and also you're powervalve issues, I'd be very carefully going back through the PV assembly, the air intake and exhaust, replacing a plug, replacing the fuel, and thorougly cleaning and inspecting the carb. Blow out/jets and fuel passages, check the needle is secured in the slide, collar and spring, check float levels! Throw an inline filter between the tank and carb too.
Work methodically.
Also I will try changing the spark plug cap, are they universal? I have access to a kx 125, crf 250, crf 250 and a ktm 125. Which would work best?
Also how would I go about spotting a bad crank seal? I thought the bike would smoke a lot more than usual? Can I buy the seals at a local seal/bearing place or would it have to be ordered?
Also how would I go about spotting a bad crank seal? I thought the bike would smoke a lot more than usual? Can I buy the seals at a local seal/bearing place or would it have to be ordered?
barossi73
Gold Level Site Supporter
If turning off your fuel tap definitely helped then float level/replace viton is where you should start imo.
When you remove float blow through viton passage,also hold float up to ear and shake to be sure its sealed,not half full of fuel which wouldnt help it float correctly!
When you remove float blow through viton passage,also hold float up to ear and shake to be sure its sealed,not half full of fuel which wouldnt help it float correctly!
