one cyldr wont fire

[bryan665]

just finnished replacing push rod tube seals and of course the gaskets, now left side wont fire ive got spark and gas and 125 psi , valves adjusted put hand over carb end while running no change but sucks good hand over right side kills engine right now, and idle wont go below 2500 rpm, help 81 r100

[lkchris]

gas in float bowl?

[20774]

When you put your hand over the left carb intake, do you feel the engine pulling air through? If it doesn't, you'll need to recheck your valve adjustment.

[bryan665]

there is gas in float bowl and it does suck your hand and i still dont know why the idle is so high the carbs were not adjusted and the tabs are on the idle screws

[James.A]

Shoot some ether(starting fluid) into the left carb and give it a try. Spark, fuel and compression is all you need to make a cylinder fire. When you pull the left plug and jam it into the plug wire cap and lay it against the left head, does it throw a blue spark when you roll the starter? If not, perhaps the plug was damaged at some point. Try switching plugs from side to side and see if the problem follows.

If the problem manifested itself after the recent work you did on the bike, that would be a good place to start looking for a fault. Push rod seals and gaskets don't lend themselves to side specific faults. Perhaps you made a mistake in the valve adjustment. Think it through and get back with us. I love a mystery.

[James.A]

Check to make sure that your throttle cables are allowing the throttle levers on the carbs to drop to the stops(idle adjusting screws). Also, an intake leak can allow a motor to draw air and idle up. Shoot that ether at the rubber sleeves between the carb and the head. If it causes an increase in RPM, your'e sucking air.

[Bill Burke]

Shoot some ether(starting fluid) into the left carb and give it a try. Spark, fuel and compression is all you need to make a cylinder fire. When you pull the left plug and jam it into the plug wire cap and lay it against the left head, does it throw a blue spark when you roll the starter? If not, perhaps the plug was damaged at some point. Try switching plugs from side to side and see if the problem follows.
I like this approach too. How sure are you that you've got a good spark on that side? Switch the plugs and check the gap on both. Meanwhile, if you have a multimeter, use it to do a simple spark plug cap-to-cap check: one probe in one cap, the other probe in the other cap, multimeter on the resistance setting. Should read in the 20-23,000 range (assuming you have 5K ohm caps). This test will give you a quick read on whether or not a cap, wire, or coil is causing the problem.

[rbtyndall]

I have experienced two head slappers.
1. Check to make sure your enricher valve is not stuck open. I had the set screw come loose on me and ended up riding for several days with the enricher wide open. This flooded me out at idle, but balanced itself out at speed.
2. Check your float bowl standpipe for clogs. Don't get it mixed up with the float bowl overflow, the pipe I'm talking about is in the casting of the floatbowl (i think on the right rear of the float bowl). There is a very small hole in the bottom of the standpipe that gets clogged. I fought all winter with this before I realized it was there.

[bryan665]

hey thanks for the suggestions,i checked everything out and gave up for the night . next day i started the bike and it ran fine! is it possible the ign can is acting up? bryan

[flash412]

is it possible the ign can is acting up? No. The ignition is "wasted spark." That means if either cylinder fires, the other SHOULD fire since they both fire off the same impulse from the can.

[bryan665]

i still dont know what i did to stop the high idle and dead cyldr problem. i had a high idle problem last season and it just vanished like this did!