4"' compression test motor not running ?

[John Guntner]

I took both plugs out and gave each cylinder a few cicks. With the throttle closed I got 65 PSI in the rear and 60 PSI in the front. Does that sound low to you guys? The reason I"m doing this is because I'm have trouble get the old girl to fire. I've put another float in the carb and everything in the carb seems OK. I do have an NOS M88 I'm thinking of trying as I've tried everything else I can to get it running. I've changed coils, ran a new wire to the distributor, Carb, intake off and on, checked timing, valve gaps and all I get is backfires and maybe the odd putt and that's it. Help me out here. Maybe I'm missing something.

[Tom Lovejoy]

compression sounds good to me, my guess is timing is off - but that is a guess, also how is the battery? good luck

[John Guntner]

Thanks for your response. I think I may have screwed up the compression test by removing both spark plugs at the same time. Also, I think I should have held the throttle open. It was running fine until I did some work on the front wheel. Then it started acting up? I checked the timing and the battery is in excellent working order. I just tried an NOS carburetor and made no difference. So fuel must be OK, air and spark are there. The only thing I haven't do is change high tension wires but I'm starting to lean to wiring. Wait, I by passed the wires and hot wired the motor, still no luck. I'm baffled. When I get it figured out I'll add another post. I forgot to mention that if I choke it with ignition on and flood the hell out of it I get lots of back fires through the muffler and my ankle. It also sneezes through he carb the odd time.

[Tom Lovejoy]

sure sounds like the wires are crossed or something, out of time. Will be interested what you find it was, good luck.

[Steve Slocombe]

Dear John, it does sound like timing but check the ground wires as well if this is an early 45. That wire running from the timer base to the gearcase cover is important, plus I recently had a bike misfiring because the copper cable on the points was grounding internally. The low tension circuit breaker post also relies on a piece of card to insulate it from the body. It might also help to pull the spark cables at the coil, strip back the insulation a quarter inch, then make sure they are pushed right home again.

[koanes]

Before you start pulling wires out of the coil just check for good spark. Lay the plugs on the cylinder head or use a clip to get a good ground. Rotate the motor to a position where the points are closed and snap the points open manually. If you don't get a good spark at the plugs it is probably something along the lines of what Steve mentioned. Check to make sure the points plate is grounded well to the motor, sometimes you have to take it apart and clean the surfaces underneath, and look at the insulator where the points pivot to make sure it is intact. If it is cracked or separated you will get a weak or intermittent spark.

[hogchild71]

John. Try replacing the condenser as well as all of the checks mentioned by others. Good luck, Fred.

[John Guntner]

45" miss fireing

I'm rewiring the bike with the proper type of wire. The last owner wired the bike with plastic covered wire and I now suspect it's a wiring issue. Once I get that done I'm sure my problems will be solved. More to follow. Thanks guys....John

[sirhrmechanic]

John. Try replacing the condenser as well as all of the checks mentioned by others. Good luck, Fred.

^^^^ This. Always start with condenser. I've pulled more hair out because of bad condensers...

Cheers,

Sirhr

[bselph]

I just went thru the same thing and it was the condenser.