After long thought COILS

[TheCafeKid]

I didnt see anything reguarding a valve adjustment in there. Have ya done that? muey bueno imortante. I am not sure that its the soul cause of your issues, but it sounds somewhat suspect if temperature causes a pretty drastic change in running condition.

[greg78gs750]

i second the valve adjust. cant tell you how many threads i read that say "cleaned the carbs 3 times, new coils, etc, still wont run right" and they still havent done the valves. like cafe kid says, maybe not your issue, but you gotta rule out the easy stuff. maybe you have already done it, and maybe someone will come along and say "it not yer valves, dood"....but....getting mine in spec fixed all my troubles. after i dipped the carbs twice. and got new coils. etc etc etc.

greg

[toolsmech]

ok valve adjust

Ok how do i do a valve adjustment? i realize where i must start but is it like a car at all where you have lifters and a set screw with a nut around it? do i need to use feeler guages to set it? please let me know what i should do!! thanks a ton for the ideas guys!! you all ROCK
Thanks Justin

[psyguy]

see bikecliff website for valve adjustment and definitely do it

but at this point i would suggest you have a major air-leak in the intake system or you are not getting enough fuel
"all over the place idle needle" is a sign of a very lean condition

with the cooler outside air your bike should perform BETTER not worse

if you are confident that you put the carbs back together properly i would start looking for the air-leak (inspect the carb-to-engine boots (for cracks) and orings behind them, as well as the boots' clamps)
also the airbox itself and the carb-to-airbox boots have to be sealed well

[Ola]

I posted this in another thread but always nice with some more feedback. My coils are showing 11.6 volts and 4.5 ohm at the primary. Secondary on 1/4 was 35K ohm but on 2/3 it was 25K. Is this a "maybe something wrong" or "definitely something wrong" situation?

My symptoms are stumbles between 2-4K when the engine is hot, sometimes right away if the bike has been sitting in the sun. It definitely feels like I'm a cylinder short in this area and there's the occasional pop from the pipes when I accelerate (not while engine braking at idle throttle). When the revs climb through 4 - 4.5K it jumps back to life. I know the regulator kicks in somewhere around this area, perhaps the stronger voltage helps overcome any poor windings to give good spark.

Please confirm or poke holes in my theory before I spend money!

[tfb]

"occasional pop" -- sounds lean.

BUT do your valves first. You must have the basics right before you attempt the rest of the stuff!

[Ola]

"occasional pop" -- sounds lean.

BUT do your valves first. You must have the basics right before you attempt the rest of the stuff!

I've done my valves. Some were off tight, some were off loose. Didn't change the symptoms, but the symptoms themselves come and go. Last week it wasn't there at all, now it's back consistently.

The occasional pop comes when I roll on throttle in the 2-3K revs area. If it was lean (plugs look good) I'd expect popping on steady throttle, idle and deceleration as well, it's fine there. If the spark is poor I'm thinking the pop comes from a missed combustion and the charge going off in the pipe.

[80GS750]

hey toolsmech, im in omaha....

maybe we can plan a ride some time and tinker with your bike if you havent gotten it all figured out by then.

[Ola]

Secondary on 1/4 was 35K ohm but on 2/3 it was 25K. Is this a "maybe something wrong" or "definitely something wrong" situation?

Bumping this particular question as I suspect it is my smoking gun. Any input appreciated!

[don_gibb6512]

Less resistance means that you're shorting wires and not going through the entire coil. That effects voltage and possibly current on output which would weaken the spark under load. This could come across as the stumbling you're feeling between 2-4k rpms.

[82Shafty]

I am getting 12 volts at the coil. Symptoms idle is all over the place. I cant let it idle below 2500 or it just dies off. It will idle ok if it is around 2700 rpm but its a pain in the butt to sit at a stop light with the engine reved like that. when i go to work in the afternoon the bike runs great 75mph (kinda warm out). but when i head home in the morning the bike wont even get to 55mph (kinda cool out). I have rebuild and dipped the carbs. The cylinders all have Great compression. The petcock has been rebuilt. New battery. umm cant really think of anything else
Thanks for all the Help Justin

She's lean son, fatten it up. Double check float heights, and idle mixtures. Make sure you have an air filter in place.

If it's warm out and she runs strong, its lean, but a cool-dense air requires more fuel per molecules and therefore, with a lack of fuel, your shiznat doesn't want to get out of it's own way.

[82Shafty]

I've done my valves. Some were off tight, some were off loose. Didn't change the symptoms, but the symptoms themselves come and go. Last week it wasn't there at all, now it's back consistently.

The occasional pop comes when I roll on throttle in the 2-3K revs area. If it was lean (plugs look good) I'd expect popping on steady throttle, idle and deceleration as well, it's fine there. If the spark is poor I'm thinking the pop comes from a missed combustion and the charge going off in the pipe.

Pull your air filter out and go drive around, if it no longer pops you are rich, if it pops worse, you are lean. If nothing changes, then research electrical.

I have had almost all four NGK caps read infinite ohms due to age and the bike still ran well. I replaced all four caps to reduce the strain on the coils and prevent any internal firing.

[Ola]

I'll be cleaning out my carbs tomorrow, that's free while new coils are expensive, so we'll see if there's any improvement. I tried spark checking as per the manual, connecting the timing inputs on the ignition module, but didn't get a spark. This is because my engine and frame is painted in that area and there wasn't any place to ground the plug.

I'll try removing the filter (after cleaning the area around the airbox thoroughly) if the stumble comes back hard again. If I'm lean I think it indicates clogged jets as the bike completely stock aspiration and carburation wise.

[toolsmech]

Ahhhhhh!!!!!!!!!

ok got into the valves today and i could not get my .038mm feeler guage inbetween the cam and the valve. is this something that would make my bike run like crap? I have capped carb fuel needle valve so they havent been adjusted. I just cant figure it out...
Justin

[psyguy]

ok got into the valves today and i could not get my .038mm feeler guage inbetween the cam and the valve. is this something that would make my bike run like crap?

yes

I have capped carb fuel needle valve so they havent been adjusted. I just cant figure it out...

if you are talking about the carb bowl floats, yes they need to be adjusted to a specified height