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Discussion Starter #1
Just picked up a 95 Mach 1 670. Fires up in 1-2 pulls, but 1 cylinder misses or is dead at idle until you get on it a bit then it kicks in. Noticed alot of fuel/oil mix is coming out of the can onto the ground. I pulled the carbs off and cleaned the jets out (didnt notice an ports plugged or anything) and put them back on. Still the same issue, alot of fuel/oil mix coming out of the exhaust and the one cylinder not firing at idle speeds. Both cylinders have good compression and both have good spark. Any ideas? or suggestions?

could it be something with the oil injection pump or would that be affecting both cylinders? Guy I bought it from said something about putting a new fuel pump on it and that the carbs needed to be synced or something, but the slides are opening and closing at the same time.....Any help appreciated!
 

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try new spark plugs, test for weak spark and check coil caps and wires
 

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it's carburated not a fuel pump isue it's ether not burning the fuel on one or flooding it, so if you got spark and it's not weak try syncing, air screws too
 

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Discussion Starter #5
I didnt do any tinkering with the air screws or anything, I'll have to play with those next time I get a chance to work on it. Is there a spec on what these are supposed to be set at from the factory?
 

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My 97 Mach would do the same thing. Once I synced my carbs this never happened again.

I chased this issue for months. My carbs appeared to be synched, but they were pretty far off, even when I would grab the throttle and let the slides crash down it SOUNDED like they were synced, wasn't until I took a screw and placed it under the slide and slowly grabbed the throttle and let it go that I realized they weren't synced. The smallest amount is going to cause all kinds of idle issues. Sync'em!
 

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Or you have a failing cylinder and compression is too low.

Could be a needle and seat flooding that cylinder a little bit all the time,
which would explain the fuel your seeing on the ground.
 

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Discussion Starter #9
Well since I work afternoons and havnt been able to work on the sled at all I had one of my buddies take a look at it. Everything seemed to check out ok with the carbs, and I also told him about the previous owner changing the fuel pump. He found the lines going to the pump reversed so it was sucking fuel directly into the crankcase. So it runs on both cylinders now but apparently acts like its starving for fuel at times. Maybe the fuel pump got messed up from being hooked up improperly?
 

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Discussion Starter #12
Whats a good place to get parts for something this old? And thats all I can tell you my buddy said the fuel lines were hooked up wrong so it was sucking fuel into the crankcase
 

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If the fuel lines on the fuel pump were reversed the sled wouldnt run at all. Rebuild the fuel pump and look through the carbs again.
Well I went out to work on it today. The lines to the pump were hooked up wrong(From the previous owner). Pulse line was hooked up to the pump out and one of the lines going to the carb was hooked to where the pulse line should be. Ran it today and it was running on both cylinders but was smoking like a freight train, eventually it died out and wouldnt start back up.
Pulled the plugs, they were soaked. We were pretty much stumped at this point. Pulled the carbs back off again, fuel dumping into the carb boots as we pulled them out. I pulled the engine over, fuel spraying out of the top of the diaphram on the fuel pump, the carb boots and out the head from the plug holes. The crank was full of fuel still.
Took the pump apart, checked the diaphrams ect... everything looks good no rips or holes.
Put everything back together and decided to try and fire the engine up with the fuel valve off to burn all the excess fuel out of the crank. Engine would run GREAT with the fuel off, until the bowls emptied out. Turn the fuel on while its running it would die right out.
Noticed the primer did not work when we originally tried to fire the engine up, so we decided to come back to this thing since its the only other path for the engine to get fuel from and everything else seemed to be working properly.
So for giggles we decided to unhook the primer line going to the carbs and plug it. Fired it back up with the fuel off, ran great.....then, turned the fuel on. It didnt die! Idled it for a while and took it for a ride, no plumes of smoke, ran strong.
That was really the last thing I would of ever thought it would be. The damn thing sucking fuel though the primer. Oh well, its fixed! Thanks for all your input!
 
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