Strange no start has me a bit baffled....

[great white]

1989 FJ1200.

So, I haven't done a lot of troubleshooting at this point, just skimmed the surface.

The bike was running pretty good, keeping in mind it's a bit of a hack right now.

I pulled the tank (unbolted and spun it) and changed the plugs for new ones. While at it, I cleaned up a couple of the spark caps as they metered as "open". Once cleaned up, they all showed right around 10K.

Gave 'er a hit of the starter and it fired up on choke. Then I heard a "pishit" noise that I've heard a couple times when it's cold and warming. I'd always though it was a bad plug misfiring. That's one of the reasons I was changing the plugs.

But closer inspection reveals the Sync ports were all blocked with a screw in a piece of hose (this bike has had quite a few uncaring previous owners).

Except for number 4. Chunk of hose, but wide open.  Aha! that's why it runs a bit poorly, starts hard and is cranky until fully warmed! Probably why the plug came out so clean; lean as a mother!

Or so I think....

I plug the port with another screw and fire it up.

It only starts on heavy choke and won't take any throttle. Now that's confusing.

It eventually dies and won't restart.

I'm thinking it's acting like it's out of fuel. That;s even more confusing!

I check the fuel pump. Pull it off and it runs. Back on it goes. Pumps fuel when I test it.

Still a crank but no start.

On a larf, I pull the carb tops and check the diaphragms. Some could be better, but they're all intact. No pinholes or tears. I will likely replace them this winter why I tear the carbs down for a proper going through.

None of the fuel lines are kinked or twisted. Sure as heck not the tank to pump line.....don't ask me how I know....

The sidestand switch has already been bypassed.

The battery is low right now so cranking was too slow to keep troubleshooting. It's on charge right now.

I can't help but think I'm missing something stupid. It ran, changed the plugs, now it doesn't. Makes me feel like an amateur.

I'm not exactly a beginner at this (35+ years working on bikes, cars, trucks, airplanes, helicopters, etc), but pretty new to the FJ.

Just thought I'd throw it out there while I'm waiting for the battery to recharge and see if anyone can think of something simple I might have missed...

[FJmonkey]

Use the drain port on each of the float bowls to see if you have fuel in each carb. Use a piece of tube and small container to catch the fuel. This way you can get a feeling if the volume that drains out is similar for each carb. Air, Fuel, and Fire (spark), check all the simple/easy stuff first.

[fj johnnie]

 Spinning the tank around can kink the fuel line. I have seen it a few times myself. It then starves for fuel. It may sound obvious but .....

[great white]

Spinning the tank around can kink the fuel line. I have seen it a few times myself. It then starves for fuel. It may sound obvious but .....

Checked. Looked fine. I'll check again though....

[great white]

AHA!

Got it sorted.

It was a kind of a "double whammy" effect.

First, low battery. Not enough umph to spin it over quick enough and I was just chasing my tail with it in a "no start" condition and slow turning. Recharge fixed that issue.

With it turning over good it actually caught but ran like poo.

The it struck me: someone had to have adjusted it to run with that vacuum leak. I even remember having to give it a little "tweak up" to get it running smoother when I first brought it home.

That means the idle would have been too fast with the leak at the stock setting. Since it was idling at the 900-ish rpm it was supposed to, that means someone had to have turned the idle screw down. Now that I'd plugged the leak, it would be set waaaay too low.

So with it running like total poo, I stuck my hand in under the carbs and gave 'er a good twist.....


Varoom!


Yup, it sure liked that. A little fine tuning and it's turning 1000-ish rpm and running smooth. 100o seems to be where this bike likes to be to minimize the chain snatch noises the starter makes.

I shut it down and start it hot: Varoom! Pretty much fired off on the first turn.

It also doesn't really need choke to cold start anymore, which makes sense because (IIRC) the choke is actually an "enricher". With a massive vacuum leak like it had, needing choke to start makes perfect sense.

Except that while it was probably making #4 right around where it should be, it was making the others too rich. That was pretty much born out by the removed plugs condition: #1-3 were on the black side, #4 was indicating very lean.

So, it was kind of a cascade effect, all caused by one missing vacuum plug.

Just gotta love trying to figure out what "buck-shee" previous owners have done to an old rig.

It's going to have to be a "stem to stern" rebuild this winter before I can trust this poor, old, neglected stepchild to go anywhere besides a short jaunt back and forth to work or around the block. I'm actually surprised it ran as good as it did.

But the good thing is that the basic bike seems solid under all the 10 second fixes.....

[Firehawk068]

The idle speed was probably adjusted while it had a good sized vacuum leak.
Now that you've fixed the vacuum leak, you will most likely have to adjust up the idle speed.
You should probably adjust the mixture screws while you are at it.

I would take all those hoses that have screws stuck in them, and throw them in the garbage.
Get the proper vacuum caps from Randy.
Don't use thin-walled automotive vacuum caps either.
Use these----> http://rpmracingca.com/proddetail.asp?prod=VacCap&cat=39
They are the proper ones for the FJ.
You need (3) of them.
Your '89 should have a vacuum hose that runs up into the fairing, and hooks to the ignition advancer. (small little box with a hose nipple on it)
It usually hooks up to the #2 cylinder port.

(edit): It looks like you figured it out while I was typing my response. 

[great white]

The idle speed was probably adjusted while it had a good sized vacuum leak.
Now that you've fixed the vacuum leak, you will most likely have to adjust up the idle speed.
You should probably adjust the mixture screws while you are at it.

I would take all those hoses that have screws stuck in them, and throw them in the garbage.
Get the proper vacuum caps from Randy.
Don't use thin-walled automotive vacuum caps either.
Use these----> http://rpmracingca.com/proddetail.asp?prod=VacCap&cat=39
They are the proper ones for the FJ.
You need (3) of them.
Your '89 should have a vacuum hose that runs up into the fairing, and hooks to the ignition advancer. (small little box with a hose nipple on it)
It usually hooks up to the #2 cylinder port.

(edit): It looks like you figured it out while I was typing my response.  

Yep, found it.

Thank for the link to the caps.

They'll get sorted this winter with the rest of the bike.

My 83 Venture is my reliable bike, this one is just a plaything for now and waiting for a resto later down the road.

I'm just sort of picking at it in my spare time right now. Taking inventory of what needs to be done as it were....