Ignition problems I think...

[one_fast_ls1]

Okay, here we go. I just got the bike about a month ago. Been working my butt off trying to get it working, found out the ignition box was broken (literally). replaced that, changed out the four into 1 exhaust to a four into two... blah blah blah...

ANYWAYS- the bike only runs on full choke. The outer two cyllinders are firing, but the inner two aren't. I pulled all the plugs out and checked for spark. plug one through four are all sparking! I checked the resistance for the coils, and the resisters- the resisters are fine, the low side between the plug wires is fine, but the high side is not showing any resistance... on either coil! I can't figure it out! please help me! I am in dire need of my motorcycle!!!

Also, I don't know if it mattered, but the previous owner had the fuel pet cocks connected wrong... one outlet on each side was going to the fuel lines to the carbs... and the other outlets were connected to the boots between the carbs. and the engine. (the octopus thing is off the bike btw.) Did I miss something?

Thanks
Adam

[bikerphil]

2+3

Are carbs 2+3 getting any fuel? Open the drain on the bowl and see if gas comes out.

[prometheus578]

Idle circuit plugged.
(or some boob turned the pilot mixture screws all the way in)
Spark on all cylinders... good.
Not running on cylinders 2 and 4 means no fuel.
The carbs are linked together, so if #1 is getting fuel, so is #2.
Number two just isn't putting out to the cylinder.
Check the pilot screws on the two dead cylinder to ensure that they're open.
Turn them all the way in till they're lightly seated and back them out 1 1/2 turns. (I said LIGHTLY seated, or you'll break the tips off)

Ok.. you have spark.. and all idle pilot screws are set yet it still doesn't fire on those cylinders.. time to pull and clean the carbs.
A bike that only runs on choke means it's not getting fuel through the pilot system. Gummed up carbs.

[Peter]

Hello what I would do is take all the plugs out and place the plug back into the plug wire and place the plug close to a ground surface on the bike and holding the rubber area, and crank the engine over a few turns. You should see some good spark jumping the gap and to the bike ground.

Cheers
Peter.

[oseaghdha]

Re: Ignition problems I think...

Originally posted by one_fast_ls1
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Also, I don't know if it mattered, but the previous owner had the fuel pet cocks connected wrong... one outlet on each side was going to the fuel lines to the carbs... and the other outlets were connected to the boots between the carbs. and the engine. (the octopus thing is off the bike btw.) Did I miss something?

Thanks
Adam

Pull those lines off and cap everything.
Uh, they are not, by chance, connected to #2 and #3, are they?

[one_fast_ls1]

Sorry for the wait- been having computer problems... fixed it!

Anyway- Yes, the lines were connected to the number 2 and 3 cyllinder. I will have to plug them and figure out a better way to run some fuel lines... It's deffinitely a carb. problem.

Jets in the carbs. were completely clogged- cleaned them, put everything back on and fired it up. Sounds like it's only running on one cyllinder now. Pulled them off again- MORE CRAP IN THE JETS! I think it's time I drained the gas, and cleaned out the tank. Not only that- I couldn't get to one of the secondary jets because the head was stripped out on the screw that covers the secondary jet... Along with some other broken tidbits. I'm going to have to pull everything apart, and fix whatever I can. Third time a charm!

What other carbs. fit this bike? something newer and easier to find!

Adam.

[olebiker]

Kinda sounds like you might wanna put an inline filter on that one.

[one_fast_ls1]

Yeah, I thaught about that one, too. What's the best way to rout the fuel lines on these things?

[oseaghdha]

When they're good they're very very good.

Fuel Lines:
Cap the front nipple on both petcocks, don't need it.
Run the rear outlet to the carbs. You can go right to right, left to left, but some folks recommend crossing right petcock to left carbs(1 and 2), left petcock to right carbs(3 and 4). Add filters. I found some decent sized ones at Autozone, hanging by the PCV valves. The sintered brass motorcycle filters are crap if you are having issues with a lot of trash in the tank. They will plug up in a week.

You will have to get the stripped screw out, that is the idle jet and is likely plugged up with filth. Be careful removing these, they are easy to destroy.

The small hole in the bottom corner of the bowl is also going to be plugged up, that feeds the idle.

If you did not already; With the slide out, unscrew the main jet a turn and give it a rap to unseat the emulsion tube. Remove from the bore side and clean.

You need to have everything removeable removed to properly clean these carbs.