Starfire GT50 engine fires up but stalls prematurely

[AussieSteve]

Hm alright ill check it out... Cause it is sounding like its running ok, not a hint of spluttering or anything....

You're losing me a bit here. I thought you said you had a problem with a loose cable and the throttle having no effect.
Now it's running OK?

If the cable is loose there will be no spluttering, but the throttle will have little or no effect.

(Glad to hear the piece of drill bit worked - since it's harder it might be even better than the original rod.)

... Steve

 

[Al.Fisherman]

Like Steve, you kind of lost me with the fact that it's running OK.
Is the engine running OK at idle or while riding? If it's at idle and the throttle has little or no effect when twisted .. try this. Start bike (turn idle adjustment screw in 1/2 turn or so if you need to) and place kickstand down or balance the bike. Lean over and take the throttle case at the carb and pull up out of the adjuster, or take up the slack and twist the throttle handle...either one will increase the RPM's if the cable itself is working. If the RPS's increase the cable itself needs adjusting, if not it's in the handle, cable connection at the piston inside the carb. Although I haven't heard of a throttle cable end coming loose that could be a posibility....things do happen.

 

[Stan4d]

I had a similar problem on a chain steered forklift. (around a 1978 model) Flip the chain over. Something about it riding that way seems to strch it just a bit so that it cannot be put back on the other direction. Hope this advice crosses over, not sure it will, but it is worth a try.

 

[Hajuu]

Sorry, I must have missed the replies to this thread somehow!

It runs ok in that as long as I keep pedalling, it keeps running, because the thrust im adding keeps it turning over (at quite high revs even) but there is just no power there.

Nothing, at all. When I pull the throttle, you can hear it recieving more fuel, because it kind of sounds like its flooding, there is still however no power what so ever.

Very hard to turn the pedals as well, there isnt even enough power for it to reach a normal kind of pedalling level. However it starts ok, and when I pedal, kinda whines like its doing high rpm's..

 

[Hajuu]

If theres any extra details I can give you id be glad to, but hopefully now you get what I mean.

 

[AussieSteve]

This is getting interesting.
It sounds a little like the choke is on.
Gotta ask this, just in case - you are aware that the choke is off when down and on when up?
If I try to start mine with the choke on, (up), I get exactly the same result as you. It fires and keeps firing as long as I pedal, but dies if I stop.
(Mine starts best with one attempt at full choke, then another with it off.)

If it's not the choke, it might be any of a number of things, but it's a start.
Are you still getting any fuel leaking from the carb, indicating a possible dirty float needle jet or a punctured float? Following the flooding/rich theme. Could be the opposite, though - a blockage and reduced fuel flow to the carb.

The whining like at high RPMs. By that I guess you mean that the whine is at high RPMs, but the exhaust note is not. Sounds a bit like clutch slip.

... Steve

 

[arceeguy]

Sounds like "lean bog" to me.

 

[Pablo]

Sounds like "lean bog" to me.

Me too.

So dude - when you start it, will it idle?

When idling can you rev it?

 

[Hajuu]

Sorry for the delay in replies guys, been really busy and havent had literally even a few minutes to work on the bike..

Just spent about an hour on it, readjusted my clutch, and a few other bits and bobs.

Um, im still at the point where it will start, and run as long as I keep pedalling, but pedalling is very hard and has clearly no assistance from the RUNNING motor..

This happens with either the choke on, or off.

If I turn the accellerator, it runs really rough suddenly like as though its flooding or something, and there is still *no* power at the wheel. None.

Like I said a lot of times, it wont idle, I cant rev it with the accellerator. However it seems to do extraordinarilly high rpm's even with a normal rolling start pace. Or atleast it sounds that way..

The throttle *was* working perfectly before, so im inclined to think its nothing with the adjustment, for one, because the cable has barely any available adjustment at all in the first place, and for another, because nothing has changed as far as the throttle itself is concerned.

I had a look at the small little inlet tube thing on the carb (the clear tube that has a mount underneith the carb, I can only assume its an intake?), and it had liquid in it which I think might have been from when I had a fuel leak. I removed the tube, blew it out, and placed it in a clear position not under the carb but still below it.

Any more information I can give, just ask as this is my only night off for atleast a week.

Cheers guys.

Hajuu.

 

[Hajuu]

I realise you guys probably can't diagnose this without really experiencing it, so shortly I will take a video and upload it somewhere

Hopefully that will help.