"flap"?

 

He is referring to the throttle butterfly valve

 

Welcome to the forum

 

Is this “ new “ carb an Amazon special? Because if it is, that is your problem. If you have the original OEM carb rebuild it or have it rebuilt by someone who knows how.
It is nearly impossible to get the cheap Chinese carbs to work. It happens, but not very often.

 

I do have the Mikuni carb and will give it a try.

 

Sounds to me as if the crankcase is full of fuel from setting for a long period with the petcock left on. I recommend draining the crankcase and oil tank - install a new oil filter, new oil and try again at ease with having eliminated one possibility of not starting due to a flooded crankcase.

 

Thank you - will give this a try after replacing the carb.

 

Ok, put the original carb back on (rebuilt a few months ago) and no joy - same as new carb - it occasionally sputters but nothing. Drained the oil reservoir, the crankcase and change out filter, topping off with 2L of recommended oil. Crankcase smelled like fuel and the oil reservoir had thin oil. I checked the plug again and this time no spark - disconnected the plug connection with the wire that goes to the coil? And it looks like it has no connection. It use to have a small wire as its end. I guess it came detached when I pulled on it. Check to see if the wires to the coil? We’re getting power and they are. All this to say again - no spark now.

 

Should be getting a new plug wire and coil in tomorrow

 

Installed the coil and plug wire, check for spark, connected wire to engine plug and turned over. Didn’t start. Seemed like it wanted to but never did. Tried three times. I’m thinking timing but not sure at
This point.

 

Timing is set by the crankshaft - when is the last time the valve clearance was checked?

 

I don’t know but here is what I’ve done so far:

1) adjusted the timing so the crank, chain and top sprocket are all aligned.

2) adjusted the four valve clearances to .006

3) regapped the spark plug to .069

4) used starting fluid and it started up, but needed a lot of choke. It was also smoking through the exhaust at the connection to the engine (manifold?). Probably the fuel in the bottom that you pointed out previously.

I have started it up four times now and believe it isn’t getting the fuel it needs - requires some choke or heavy on the throttle to keep it going.

what are the things I should look at to get it to idle? Thank you!

 

Obviously the valve clearance was just checked.

Typically they idle but won't take throttle. Not idling usually indicates bad fuel or the carb needs calibration - if you changed the carb, what did you install in place of the Mikuni BST carb? I'll buy the BST carb for what you paid for the replacement carb.

 

I changed the carb to after market - not sure of the brand - it was approx $34. Earlier in the thread somebody else recommended putting the original carb back in - so I did. I refurbished it a few months ago with seals and cleaning - not sure how good that was. Fuel is fresh sitting maybe 3 days.

can’t sell the original - I’m giving this thing back to my brother. He will want it. I guess I could put the aftermarket back in? And see if it will perform better?

 

Ok - just changed the mikuni carb out for the after market - starts right up and after an idle adjustment let it idle at 1340 rpm - did that by sound - not sure what the idle rpm range is. Appreciate the assistance gentlemen.