I can't seem to get it to fire up after rebuild

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49txpan
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Location: Houston

I can't seem to get it to fire up after rebuild

#1

Post by 49txpan »

Guys I appreciate the help I get here. I have completed a total rebuild of my 49 Pan. Cases split, new bearings and races throughout, new pistons, new cam, carb rebuild, glass beaded, etc, etc. All went back together ok and all parts are same spec. I can't seem to get it to fire up. The timing marks are visible ( the parallel marks on the flywheel), the points are on the small lobe for front cylinder and gapped at .022". The Keihin carb is squirting a good stream. I know there is good fire as I checked it. I can make it backfire once in a while, even got a carb flame. Any ideas? My gut says I don't have something correct with the timing.

Thanks,

Russ
kell
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Re: I can't seem to get it to fire up

#2

Post by kell »

Possibly you timed it on the exhaust stroke.
Jack_Hester
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Re: I can't seem to get it to fire up

#3

Post by Jack_Hester »

Your flywheels should have a single, vertical mark for the front cylinder. And, a dot for the rear. But, no matter how it's marked, just time it to the single mark for the front cylinder. These engines are old enough to have a mix of components. Fortunately, the single mark is the constant in them.

Jack
49txpan
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Re: I can't seem to get it to fire up

#4

Post by 49txpan »

Thanks. I will try that. I have two marks, the single line and two parallel lines. The mechanic I used to rebuild the lower told me that both marks are for the front with one being advance and the other retard.
Tracy

Re: I can't seem to get it to fire up

#5

Post by Tracy »

txpan49, Iassume tx is Texas, if so where in Texas do you live. I too have a 49 and live in Plano TX.

Tracy
mbskeam
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Re: I can't seem to get it to fire up

#6

Post by mbskeam »

hey.....
single timing mark, set at the back edge of the timing hole,
(this is for the front cyl.) on the compression stroke
sounds like its 180 out
I've never done this............ ;)

mbskeam
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Re: I can't seem to get it to fire up

#7

Post by fourthgear »

Taxpan49
If you have a stock circuit breaker ( distributor) it has a mark on the point cam lobe and should line up with the point cam follower if the timing mark on the fly wheel is on the money and the circuit breaker is in the right position in the case. Like is said you should have a single bar and it should be just into view in the timing hole. You can see if its right by lifting the front intake push rod cover so you can see when it opens the intake valve and then as it just closes ( of course pull both spark plugs before kicking over motor) use a small flash light or a plastic pen with out the guts and put it in the front spark plug hole to see the piston coming up to top dead center , but you don't want it to get to TDC you just want to see the piston coming up and that will let you know you should be coming up on the timing mark in the timing hole , keep an eye on the hole when doing this and it helps to have a helper slowly kicking motor over slowly to view this. It might take a couple of times to get the timing mark in the window ,but this will tell if you are timed correctly or your Circuit breaker is off or not . Good luck, I am about a week away from starting mine from a total rebuild.
49txpan
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Re: I can't seem to get it to fire up

#8

Post by 49txpan »

Thanks for the tips. I installed a belt drive and am able to dial the lines in via a ratchet/socket. I must have an after market distributer because I cannot see any timing marks per the manual or notes here. I am going at it again today. I posted a picture in the Pan secton.
49txpan
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Location: Houston

Re: I can't seem to get it to fire up

#9

Post by 49txpan »

I am learning quite a bit about the Pan. Pushrods need to be just right, able to spin on TDC. Timing is ok now but the carb is troublesome. The Keihnin I am running pretty much floods the cylinder with a couple of twists. I just ordered the CV adapter flange and am going to try a twin cam CV carb. I read some threads here and it looks pretty straight forward.
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