40mm carb jetting

Lumpy · Post by **Lumpy** » Tue Jun 16, 2009 5:48 am

Thats an interesting point made by wdietz186 about the plug gaps. At the risk of digressing a little I tried changing over to NGK Iridium plugs 1 grade hotter all at the same time of the pick up wire saga. After I got it going it ran like a clock, but kicking it over was possitively frightening. It turned into a nasty back biting cow of a thing. Even slowly rolling it over to find TDC and it would kick back ferousiously. On occasion just turning on the ignition and it would pop through the air intakes with no foot on the kicker. Went back to standard plugs and she`s as sweet as can be.

mizike77 · Post by **mizike77** » Tue Jun 16, 2009 6:34 am

As of late, mine has been popping back with a turn of the key....a sure sign of ignition problems?

wdietz186 · Post by **wdietz186** » Wed Jun 17, 2009 5:17 pm

Mostly the popping back is from combustible mix remaining in the cyl.It happens when the valves seal properly and the rings aren't worn out.The ign. sparks when the switch is turned on.My old 750 popped once after sitting for 3 days once.An added thought,check for shorted wires between the pickups.Make sure you don't have resistance when checking one lead from one pickup and one lead of the other.Squashed wires can short to each other and can cause the sort of running you are describing.Splice the wires close to the pickups but leave about an inch of the original wire.Covering the old wire with shrink tube will keep it from shorting.The proceedure is described in one of the threads.

abmartin · Post by **abmartin** » Thu Jun 18, 2009 5:06 pm

mizike77 wrote:As of late, mine has been popping back with a turn of the key....a sure sign of ignition problems?

I hope not. Mine pops back quite regularly.

Bruce

mizike77 · Post by **mizike77** » Fri Jun 19, 2009 7:38 pm

Seems to be a bit of copper showing coming out of the pick ups..maybe 1mm or less. Not good im guessing?

mizike77 · Post by **mizike77** » Sat Jun 20, 2009 4:09 pm

Continued here.... http://www.bevelheaven.com/~BB/phpBB2/v ... 0040#10040

seacoast69 · Post by **seacoast69** » Mon Jul 27, 2009 7:31 pm

Why would the front spark plug look black and oil fouled no matter how it is jetted ? We have tried everything and the front cylinder plug always comes out black, look oily ? Where would oil come in from ?

Post by **BevHevSteve** » Mon Jul 27, 2009 11:11 pm

Sure - the valve seals and / or valve guides are most likely shot and letting oil in....

seacoast69 · Post by **seacoast69** » Tue Jul 28, 2009 5:32 am

Even if it doesn't smoke when running ?, puffs a little at start. Seals are new, guides ???? Didn't have them measured when they where gone thru that we know, but I would assume the shop would check that.

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40mm carb jetting

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