Dead bike

[rosso75]

I've got a dead bike.  I've been searching all kinds of stuff, but my problem is not that I'm having trouble finding answers.  It's having too many answers.  With my limited FJ knowledge, I suspect I'm chasing problems that I don't actually have, so I'll apologize in advance if I'm asking questions that everybody but me knows the answer to.

I got an '86 last summer.  With the choke on full, it would start barely, run briefly, and die as soon as I'd twist the throttle.  It would do this repeatedly.  The guy I got it from said he bought it that way, and told me "I posted a bunch of questions on a forum online, but I never did get it running."  I don't know if he was here, but I'll include a pic in case it jogs anybody's memory.  Best pic I have of the bike in one piece.



About a month ago I found another '86.  It runs, so I figured the best way to fix a non-runner is to just swap parts with an identical running bike.



When I first messed with the non-runner last summer, I found what seemed to be a weak spark from one of the coils, and very minimal fuel flow from the tank, but I didn't really have time to pursue things further.  Now that I have a runner, I've swapped both coils and the ignitor unit.  Dead bike still dead, runner still runs.  I'll be checking more stuff today.

I have a Clymer manual, though I don't know how good a non-factory manual is.  According to the VIN info listed, both are 49 state 1986 models, but I found both bikes have different petcock valves.



The non-runner has what the manual indicates is the proper petcock....manual on/reserve valve, with a vacuum diaphragm.



The runner has a petcock not shown in the manual....no manual valve, and electrical rather than vacuum control.



Since they're both '86's, I assume they should be the same.  I therefore also assume one of the petcocks (or tank) was changed at some point.  Both bikes are wired for the electric one, but the manual shows the other as the proper one for the year.  I get a much greater fuel flow out of the electrical one, though I suppose both flow a sufficient amount.

I pulled the carbs off the runner and mounted them on the non-runner, thinking maybe one set was gummed up from sitting.  I also mounted the runners tank, with the electric petcock.  I was able to get the non-runner to idle on full choke for about 15 seconds, but just as when I bought it, I hit the throttle and it died. 

While doing this, the non-runner was cranking very slowly.  The other bike cranked normally with the same battery in it.  I pulled the battery out of my car and hooked it up with jumper cables to add some extra amps.  It cranked much better, and that's when it briefly started, but I haven't been able to get it to run again.

So at this point, I don't even really know what semi-intelligent questions to ask.  If I've got weak spark from one coil, and given the way it cranks I'm guessing I probably have multiple bad connections somewhere.  I'm about at the point where I'm ready to tear the bike down completely and clean everything as I put it back together.  I have a '90 that became an unintended long term (3 years) project in much the same way though, so I'm a bit hesitant to go down that road again.  Is there any part of the system that would cause weak spark in just one coil, which is otherwise known to be good, or would both coils be effected by other components that may be bad?

Should I be concerned about this petcock?  Based on the diagrams in the manual, it seems to be missing a fuel screen that goes up into the tank.  Plus, given that the bike is wired for the electronic one, is that what I should have on there?

I haven't done a compression test, and know I should, but I can't find an adapter locally for the spark plug hole on the bike.  In the mean time, any thoughts appreciated.  I'm trying to turn this mess into two running bikes.

[Pat Conlon]

Clean the carbs on the maroon bike...clean them correctly.

Read the Carb Files.......Study the Carb Files. Roll up your sleeves and do it...

We have documented all the information you need to do the job correctly. We worked hard on this. We did this for a reason. We get the same questions over and over. How do I clean my carbs?
We tend to get cranky when people don't read it...

Remember...Carb cleaning 101: Half measures will avail you nothing. Do it right.
Any parts you need for the carbs are available from RPM.

I've not seen a vacuum petcock like that. No clue were it came from. The '84/85 petcocks are a less expensive alternative to the pricey '86-87 reserve petcocks...also available from RPM. See the vendor file section.

You are going about it wrong....instead of swapping old parts from a running bike to a old non running bike, fix the parts on the non running bike (like the carbs)

Pick one bike and work on it...step by step....failure to do so will send you into vapor lock.

[simi_ed]

FTHY

Clean the carbs on the maroon bike...clean them correctly.

Read the Carb Files.......Study the Carb Files. Roll up your sleeves and do it...

We have documented all the information you need to do the job correctly. We worked hard on this. We did this for a reason. We get the same questions over and over. How do I clean my carbs?
We tend to get VERY cranky when people don't read it...

Remember...Carb cleaning 101: Half measures will avail you nothing. Do it right.
Any parts you need for the carbs are available from RPM.

I've not seen a vacuum petcock like that. No clue were it came from. The '84/85 petcocks are a less expensive alternative to the pricey '86-87 reserve petcocks...also available from RPM. See the vendor file section.

You are going about it wrong....instead of swapping old parts from a running bike to a old non running bike, fix the parts on the non running bike (like the carbs)

Pick one bike and work on it...step by step....failure to do so will send you and US into vapor lock.

[jscgdunn]

Great advice Pat:
Step 1) Put the Red/white back together...hopefully it still runs and you can find everything and where everything goes.....
Step 2) Ride it and enjoy it....
Step 3) Use the motivation from the enjoyment above  to clean carbs on the modded bike..

Good luck

Jeff

[rosso75]

I know carbs have to be gone through meticulously.  It's on my list.  I did know enough to not ask about how to clean or tune carbs.  Gotta get at least one point for that, right?

I figured it was worth a try though, pulling carbs off a running bike.  Even if it ran poorly, it would have possibly told me if I was chasing a fuel problem or an electrical problem.  Just out of curiosity, I'm going to put the carbs from the dead bike on the runner and see if it starts up with them.  Regardless, they'll get cleaned.  With these two and my '90, I might even know what I'm doing by the time I get done cleaning 12 carbs.

Thanks for the input

[andyb]

Try to start the bike.  It fails to start.  Shoot ether at it, or a spray bottle of gas.  Does it make good noises, or does it not fire?

Remove spark plug.  Hold in bare hand while attached to coil.  Try to start bike.  If it kicks your ass, you have a fuel problem.  If you're left standing, you have a spark problem. 

If you remove the plug after trying to start the bike and it smells of gas, it's more likely spark than fuel.

If it's been sitting for any length of time, you have a fuel problem.  Period.  You may also have a spark problem.  You will manage to fix neither unless you methodically look at them one at a time.  It's just a motor, same as your lawnmower.

[ribbert]

Remove spark plug.  Hold in bare hand while attached to coil.  Try to start bike.  If it kicks your ass, you have a fuel problem.  If you're left standing, you have a spark problem. 

Andy, for a self proclaimed novice looking for advice (and one who is already confused by the advice he's had) the above is vague, inconclusive and not very scientific, as is "shoot ether at it" without explaining how (such as raising the slide before you spray).

Noel

[Arnie]

Noel,

You're right, AndyB's comment was a fatuous attempt at humor, which probably was not the best thing to post to an admitted novice looking for knowledgable advice.

However, I thought it was funny (and mean) enough to copy and send to all my mates with a modicum of mechanical nous :-)  I would probably rate the humor contained as about equal to those gag fart pillows or squirting flower lapel pins.

[Dogsbestfriend]

Greetings from the uk.
Try cleaning up the main earth lead or running an extra one down to the starter mounting bolt.

[movenon]

Greetings from the uk.
Try cleaning up the main earth lead or running an extra one down to the starter mounting bolt.

Welcome ! Good grounds are important. You shouldn't have to install an extra wire though at the starter if the main wire is in good shape.
George

[mr blackstock]

The carb cleaning suggestion is the best place to start.  When I first got my '85 I had to clean the carbs three times until I got it right.  On my bike she never turned over fast enough to fire up.  I researched and discovered I had a three brush starter motor.  I ordered a four brush starter motor of Randy and the bike started up easily.  A slow starter motor will affect everything.

But a great starter motor will not help clogged carbies, and from what I can gather, these bikes are very particular about good fueling.

Once you do the carbs, look at the choke plungers, ensure they are not trying to move in old hard rubbers, the fuel line can be altered for easier tank removal, wire up you fuel cock for safety, consider new carb diaphragms, cheap ones are at http://jbmindustries.com/ they work very well, or buy the genuine ones from Randy.

But basics first, carbs and a starter motor.

Good luck.

Cheers, Gareth

[rosso75]

AndyB's comment was a fatuous attempt at humor, which probably was not the best thing to post to an admitted novice looking for knowledgable advice.

However, I thought it was funny...

I got the humor in it.  I prefer other coil testing procedures, though I appreciate the suggestion. 

And I get the 'new guy asking dumb questions' thing too.  I'm on several car forums, and there's always some 19 year old kid who asks about something there's 100 threads on because his attention span is like 9 seconds and he couldn't be bothered to read, assuming he knows how. 

For the record, I've got some skills, but after so many years it's easy to just find yourself sticking to what you know.  I'm a Volvo guy.  Most every knock, or tick, or non-running issue, I'd know where to start looking.  I'm familiar with their idiosyncracies. 

The bike is out of my comfort zone.  My main issues are...

1.  I grew up in a fuel injected world.  I know nothing about carburetors.

2.  I know nothing of common FJ issues.  To use an example that I know, when the PCV system gets clogged on a turbo Volvo, it blows blue smoke and is often diagnosed as a bad turbo.  It's the difference between a thousand dollar repair vs. a sixty dollar repair.  Little issues like that, if they show up on my bike, would have me chasing stuff totally unrelated to whatever my actual problem is.

3.  And that brings me to my third issue...information overload.  I could spend all day here, and elsewhere, reading.  Not that I wouldn't enjoy that, but I do have to work/sleep some time.  Plus, it's easy to forget new info coming in when you don't know what your doing in the first place.

Anyway... I've got one set of carbs apart, being cleaned, and have more questions.  When I reinstall the mixture screw, is there a baseline for getting it close to where it should be set?  All the way in, then back two and a half turns, or something like that?  And when it's running, how do I know when these are properly adjusted?  I'm trying to remember a brief lesson on carb adjusting from way back in high school shop class, but even then there was only one carb, not 4.  I'm assuming there's a better way than just running it for a while, then checking the plugs.

I looked a couple times and didn't see it in the carb guide.  If it's there, and I missed it, please refer to #3 above.

Thanks

[rosso75]

I've got a steady drip of fuel coming from one of the overflow tubes.  Does that mean one of my float levels is out of whack?

[andyb]

Nah, I give up.

[Pat Conlon]

When you removed the float needle seats for cleaning, did you replace your needle seat o rings?


2.5 turns out (from seated) is a good place to start on your idle mixture screws...