|
|
Post by hopwheels on Oct 20, 2006 16:30:06 GMT -5
So, with an 11:1 piston, what octane fuel should I use on my '79? Is there an octane booster additive that would work (specific brand, or is the car stuff ok to use)?
I'm thinking it's not electrical that the bike isn't starting. The plug has spark, and I'm getting the correct resistance readings on the ignition coil and stator (now that my bro talked me through how to work the dumb multimeter).
So could 91 octane gas (the highest available at the pump) be my issue?
Gary
Hopwheels
|
|
|
|
Post by thumperbill on Oct 20, 2006 17:59:28 GMT -5
Probably one of 2 things. Timing may be off or your plug needs cleaned. I have seen brand new plugs and for whatever reason they get a little fuel in them and wont give a good spark. I pull the plug, kick the bike over with the throttle wide open a bunch of times to clear it out. Clean the plug really good (emery cloth works really well). I also clean the porcelin tip with steel wool and blow it out with compressed air. Check for fat spark and try again. Bought many a bike where this was the only issue. You really wont know on the fuel until after getting the bike to run.
|
|
|
|
Post by hopwheels on Oct 20, 2006 19:29:35 GMT -5
So, all things considerd, clean plug, timing correct, no electrical issues... 91 octane will work? And being a bit if a doofus again, how can I check the timing without a running engine?
Gary
Hopwheels
|
|
|
|
Post by mildmitch on Oct 22, 2006 1:14:44 GMT -5
Lack of octane won't keep it from running. Also, in addition to cleaning the plug, try an old trick we have used many times to get stubborn bikes started.
While the plug is out and you're just ready to replace it, heat it up in the oven or even with a lighter or some flame. Put it back in (careful, it's HOT, gloves help) and kick it over. You'll be surprised, like starting a warmed up engine.
I was taught this by a French mechanic friend a million years ago, while trying to kick over an old bike in severely cold weather, Ice and snow and all. It helps.
Good luck
Mitch
|
|
|
|
Post by theswede on Oct 23, 2006 3:22:11 GMT -5
Gary,
No matter what cam you run, 11:1 is quite high compression. You might have to lessen the spark gap to fire the plug, due to the higher pressure.
I'd be surprised if you manage to run the engine on 91oct without knocking, my guess would be around 100oct...
Good luck!
/Jonas
|
|
|
|
Post by hopwheels on Oct 23, 2006 8:33:57 GMT -5
Hey guys:
Thanks. I can't even get it to fire on 91. That's what made me think for a while now it was something else on the bike. I have 5 gal. of VP 110 I'm going to give a whirl. When I did a spark test, the spark seemed very puny. If I were to lessen the gap, just go to the leser end of the specified range (.28 to .32), or even tighter than that? I typically try to shoot for .30. Thanks again!
Gary
Hopwheels
|
|
