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FJ1100 Won't run on all Four Cylinders

Started by Spudman, June 20, 2016, 09:58:27 PM

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FJmonkey

Quote from: Spudman on June 27, 2016, 07:32:25 PM
Well it is a little late but here are a few pictures of that old petcock. Do you think it came off of one with a fuel pump? It does have the on/prime/on options but the two nipples throw me off.
That looks like a standard '86/'87 petcock, 10MM for fuel and 4MM for vacuum (goes to #2 carb intake boot). If it has a PRI position then it is an '84/'85. If it still works properly then add some safety wire, the 10MM fitting has been known to fall out spilling fuel on to a hot engine. Think fire ball...
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Spudman

This petcock has two outlets for vacuum though, which side should the line that runs to the second boot go to? and where does the other one go?

FJmonkey

Quote from: Spudman on June 27, 2016, 10:02:17 PM
This petcock has two outlets for vacuum though, which side should the line that runs to the second boot go to? and where does the other one go?
My error, you do not have an FJ petcock. See the following links from RPM
84/85 -

86/87 -

89/93 -

Not sure what the extra port is used with....  :pardon:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

FJ_Hooligan

Mark,
You keep saying the petcock vacuum port should go to the second cylinder.  That's not technically correct.  Although it can go to any cylinder, it originally went to the first cylinder vacuum port.  The ignition vacuum when to the second cylinder vacuum port.
DavidR.

FJmonkey

Quote from: FJ_Hooligan on June 27, 2016, 10:42:25 PM
Mark,
You keep saying the petcock vacuum port should go to the second cylinder.  That's not technically correct.  Although it can go to any cylinder, it originally went to the first cylinder vacuum port.  The ignition vacuum when to the second cylinder vacuum port.
Fair enough, I may be in error on the exact port. Thank you for the correction.  :good2:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Spudman

Looking at the pictures I definitely have the wrong one. I found this one on eBay that is reasonable but it does not utilize a vacuum port. Would this work well given it is still a gravity feed? I believe the vacuum just helps shut the fuel off on these, yes?
http://www.ebay.com/itm/171642705025?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

FJmonkey

Quote from: Spudman on June 28, 2016, 07:02:33 AM
Looking at the pictures I definitely have the wrong one. I found this one on eBay that is reasonable but it does not utilize a vacuum port. Would this work well given it is still a gravity feed? I believe the vacuum just helps shut the fuel off on these, yes?
http://www.ebay.com/itm/171642705025?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The vacuum control is a safety feature in my opinion. When the engine stops, vacuum drops out and fuel stops flowing to the carbs. It also prevents a stuck float valve from draining all the fuel from the tank, which may end up in the crank case or in a puddle on the ground where it is parked.

That manual petcock has an 8MM barb for the fuel, our GF feed units are 10MM. However, some here have ridden home after bypassing a failed fuel pump and that is 6MM hose. So it may work, just understand the risks/challenges that come with it.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Pat Conlon

If you don't want a vacuum shutoff on the petcock.... have you given any thought on how you plan on shutting off the gas?

Pulling off the seat and left side cover, reaching in to turn the lever every time you park?
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Tuneforkfreak

Quote from: Pat Conlon on June 28, 2016, 10:43:04 AM
If you don't want a vacuum shutoff on the petcock.... have you given any thought on how you plan on shutting off the gas?

Pulling off the seat and left side cover, reaching in to turn the lever every time you park?
Very good point. My bike does not have a shut off, not sure if my petcock is stock or not but it does not have a vacuum shutoff and I wish it did.  I've seen tiny puddles of gas dripping from the overflow tubes once or twice and I know full well where that road leads. As soon as I start the bike it stops leaking but the point remains, when not in use the gas should be shut off. Like Monkey said, the gas can all wind up in the crank case, My Yamaha Kodiak was notorious for that if it sat a little to long and you forgot to shut the gas off and I'm talking the entire tank of gas in the engine.
Yamahas from my past,
IT465, IT200, YZ80. 350Warrior, Kodiak400, Kodiak450,
Various others include
XR600, KX500, KDX200, ATC250R, ATC350X, ATC 200S
Currently ride
FJ 1200 , DRZ400, Yamaha Viking, Suzuki Samurai dirt mobile

Pat Conlon

If you're lucky the fuel will end up in your crankcase.....often times it will end up on the floor of your garage.
By chance, you don't happen to have a water heater in your garage do you?  :bomb:

....so for some extra $ (above what you would pay on FleaBay) you can get a proper petcock.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Spudman

Well despite my best efforts, soaking the carbs, clearing every hole/jet/breather, replacing o rings the bike still does not want to run. It actually runs worse than before (not at all, really). This thing is the one of the most fussy bikes I have ever worked on. I checked the bowls for gas, which they do. Checked spark again, does. Plugs were wet so it is getting fuel in the cylinders. and it still have compression. From what I've learned all I should need for at least it to fire is fuel, spark, and compression. Is there something I am missing with this bike?

FJ_Hooligan

Quote from: FJmonkey on June 27, 2016, 10:51:39 PM
Quote from: FJ_Hooligan on June 27, 2016, 10:42:25 PM
Mark,
You keep saying the petcock vacuum port should go to the second cylinder.  That's not technically correct.  Although it can go to any cylinder, it originally went to the first cylinder vacuum port.  The ignition vacuum when to the second cylinder vacuum port.
Fair enough, I may be in error on the exact port. Thank you for the correction.  :good2:

Sorry, meant no ill.  It's just much easier to disconnect/connect on cyl 1.
DavidR.

Spudman

SHE LIVES! The bike took a lot of extra work and battery charges but she screamed to life, literally. Now all I have to do is fix all the other little mechanical problems (clutch doesn't fully engage, brakes need to be bled) and get a proper petcock as you all suggested. Any other things I might want to look out for before taking her on the road? The tires are fairly new so those are good.

FJmonkey

Quote from: Spudman on June 29, 2016, 07:49:54 PM
SHE LIVES! The bike took a lot of extra work and battery charges but she screamed to life, literally. Now all I have to do is fix all the other little mechanical problems (clutch doesn't fully engage, brakes need to be bled) and get a proper petcock as you all suggested. Any other things I might want to look out for before taking her on the road? The tires are fairly new so those are good.
Awesome!!! Happy to hear that she roared to life.  :good2:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Tuneforkfreak

Just an FYI check your oil ( pull a sample)If you've not changed it yet. sometimes when they sit for a while the gas can get in the oil and it makes them really fussy to start. If your oil is thinned down that's bad too if it does start. Glad you got it running, what a great feeling :good:
Yamahas from my past,
IT465, IT200, YZ80. 350Warrior, Kodiak400, Kodiak450,
Various others include
XR600, KX500, KDX200, ATC250R, ATC350X, ATC 200S
Currently ride
FJ 1200 , DRZ400, Yamaha Viking, Suzuki Samurai dirt mobile