CARBS...I give up

Kevron99

Kevron99

New Member
Problem: Will not Idle

I have been reading in this forum about Idling problems. My MB just wont Idle!! I done everything and I think I am giving up and now consider to buy a new carbs.

Here is what I already did and seem cant find a fix.
1.) Made sure that the slide and the needle is in place and the trottle springs back
2.) Apply silicon sealer on the intake gasket and the head. Applied silicon sealer between the intake and the carbs. DId all to make sure theres no leak
3.) Open the carbs and checked the jets and the internal parts for any defects or abnormality.(did not find any)
4.) Lowered the need slide one notch down
5.) Tried running on tight idler screw and tried turning 3 to 4 turns (loosen)
5.) Checked cables and made sure is free of any obstruction and kimks. Also lubricate
6.) Punch small hole on gas tank
7.) Gasoline is on 20:1 ratio (still on a break in period)
8.) Research the forum extensively - reading threads about carbs for 3 days.

Is there anything else I should do? Any suggestions? Thanks for any help.
 
I have tried with the idler screw all tight up... and still wont idle. When I stop and disengage the clutch the motor just stop...
 
Maybe try running 24:1, a NGK B5HS plug, & replace the wire & boot with high quality replacements?

The way magnitos work is, the faster they spin; the more powerful the spark!! (slower, the weaker)
My theory here is that maybe the plug is fouling a little @ idle, & that maybe replacing the ignition parts & running less oil will make the idle stronger?

Also, get rid of the plug-ins & solder & heat shrink the wires!!!
 
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Ok I just got back from a test run after I uninstall and checked the carbs again and to make sure that the throttle screw is lifting the slide.
After the test drive, and when I stop, slightly disengage the clutch or press the clutch lever at 50% the bike idles but revving very high in full RPM, I tried to loosen the idler screw while the clutch is at 50% and the revving brings down a little bit, now it idles but RPM is still high. When I disengage the clutch at 100% the motor stops....its a real bummer. Any help from the forum is much needed...Thanks

My next is to try Venice suggestions...Replace the plug and plug wre
 
Kevron99 said:
My next is to try Venice suggestions...Replace the plug and plug wre
Click to expand...


SOLDER THE WIRES!!! (that one's kind of important! sometimes the tension from pulling the clutch cable can 'jiggle' the plug ins & cause the engine to shut off!!) ;)

I had that same problem on one of my builds... the engine ran great, but when I pulled the clutch, the engine instantly shut off!!! That's why I now solder all the wires on my builds!!!
 
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get some carb cleaner and spray it all around the intake and where the carb mounts. you might have a bad casting in the manifold with a pinhole leak. if you have to keep it throttled to run, keep it at the minimum, like where it should idle. if there's a leak, it'll sputter and die when the carb cleaner hits it.

also, this may sound totally stupid, but make sure your choke isn't stuck on.

the factory setting on the idle screw is 3-4 turns out. try loosening it a little more.
 
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Wait, when you disengage the clutch at 100% the engine dies? You mean you're letting out the clutch with the throttle wide open at a stop?
 
Kev be patient my friend. Lets explore a carb for a minute...... its extremely important that your bowl to be filled with fuel when it needs it . Your fuel is regulated in the bowl by your float and your needle valve. Your idle circuit is differant from your regulated circuit......Kev knows this.....these chinese carbs are a different creature than what im used to.
 
Contrary to the EXPERTS. ROUGH idleing is a fuel problemo. {Intake loss} or not enough fuel getting to the bowl to keep up with consumption yo the intake. Ill get hanged by what IM saying but after years of working on various equiptment Im sure of what Im saying.
 
I was using a paper filter element...switched to screen and my problem pretty much went away...noticed you are up north gotta be worse up there. Take out the fuel filter for a test run and see. It wouldn't hurt if you posted pictures of your carb including everywhere the cable runs.
 
I can attest to this, most Japanese manufacturers of engines with lawn applications do extensive studies as to what constitutes problemic perforformance of the "model # and where its sold" carburation difficulties and performomance issues.
 
Is there anything I can do to get rid of the crusty buildup in the dome of the combustion chamber? It is only building up on the front half where the fuel sprays in and hits.
 
or lean it out. i had the same build-up. then i figured out where my engine liked to run. spark plug gap, higher octane, correct fuel mixture, needle setting...

play with it. you'll know when it's right.
 
"Lowered the needle slide one notch down". Do you mean you moved the C clip one notch up? This would aggravate your problem. I think it's an air leak.

Some of these carbs come with an idle screw that isn't long enough, no matter how far you turn it in, it won't idle.

Youi said the engine either races or dies, that's an air leak.

Also, putting silicone on your head gasket is bad news.

I would remove that and replace the head gasket with no sealer of any kind. A leaking head gasket will generally show itself as a mess on the engine, and loss of power, not as the symptoms you've described. A leaking base gasket will act the same as an air leak, partly because it is.
 
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