After long thought COILS

[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!!!!!!!!!

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

 

[Guest]

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

 

[toolsmech]

nah

nah

yes




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

Nah they are in the front on top of the carb they have a cap on them

 

[Guest]

Nah they are in the front on top of the carb they have a cap on them

those are your pilot mixture screws in there
people typically remove the caps so the screws and other bits can be inspected, passages cleaned, and the screws adjusted

 

[toolsmech]

valve tappets

valve tappets

Where would i order a set of valve tappets in an asortment of sizes?

 

[Guest]

Where would i order a set of valve tappets in an asortment of sizes?

www.z1enterprises.com

but youre likely to be better off figuring out what sizes you need and ordering just those