Carb rebuild

[Dazza57]

Hi all, well after having the kits I bought from Randy sitting in the fridge for about 18 months, I finally had to bite the bullet and "DO THE JOB". It was precipitated by my mate taking EFFY for a ride and on the return she decided to drop what was left of the tank onto the ground, which I assumed would be a jammed float or some gunk in there somewhere. Parts of the bike look like they didn't see much TLC in her previous life, so rebuild the carbs it is.

We all has gone mostly well. The pilot jet with it's tiny little washer and "O" ring had me bamboozled a bit until I shone a torch down the hole and saw some bits that looked like they should come out. All good. Now reassembling the carbs into the bike, I find I have 2 lots of larger "O" rings, one set came with the new intake manifold, the other set came with the carb rebuild kits. I inserted one set into the intake manifolds in the face that meets the metal of the engine intake, and I have a spare set.

Then I got to wondering why there was a groove around the outside of the carb, the part that is inserted into the intake manifold. So I put an "O" ring on it and it fit. There wasn't an "O" ring around this part of the carb when I pulled it apart, and I cannot find anything in the parts drawings etc showing an "O" ring used here.

Can anyone tell me whether it is good/bad to use one here? I had quite a back firing problem before this rebuild, and had cleared the exhaust side from being the culprit, so wonder whether this might help.

Cheers Dazza

PS I do have a photo of the bit where I put the "O" ring, so if needed I will battle through posting it

[FJ1100mjk]

There's no o-ring used on the groove of the carb body that you described. You have a redundant set of o-rings for the intake mankfolds (for the groove on their backsides). One set came with the carb rebuild kit, and the other with the intake manifolds.

[racerrad8]

There's no o-ring used on the groove of the carb body that you described. You have a redundant set of o-rings for the intake mankfolds (for the groove on their backsides). One set came with the carb rebuild kit, and the other with the intake manifolds.

+1

Randy - RPM

[Bminder]

Randy made me clean my pilot jets so many times now I have nightmares about it... 
The doctor said I have PJSD - Pilot Jet Stress Disorder.

[RichBaker]

Hi all, well after having the kits I bought from Randy sitting in the fridge for about 18 months, I finally had to bite the bullet and "DO THE JOB". It was precipitated by my mate taking EFFY for a ride and on the return she decided to drop what was left of the tank onto the ground, which I assumed would be a jammed float or some gunk in there somewhere. Parts of the bike look like they didn't see much TLC in her previous life, so rebuild the carbs it is.

We all has gone mostly well. The pilot jet with it's tiny little washer and "O" ring had me bamboozled a bit until I shone a torch down the hole and saw some bits that looked like they should come out. That is the mixture screw, NOT the pilot jet.

All good. Now reassembling the carbs into the bike, I find I have 2 lots of larger "O" rings, one set came with the new intake manifold, the other set came with the carb rebuild kits. I inserted one set into the intake manifolds in the face that meets the metal of the engine intake, and I have a spare set.

Then I got to wondering why there was a groove around the outside of the carb, the part that is inserted into the intake manifold. So I put an "O" ring on it and it fit. There wasn't an "O" ring around this part of the carb when I pulled it apart, and I cannot find anything in the parts drawings etc showing an "O" ring used here. No O-rings on the carb bells...

Can anyone tell me whether it is good/bad to use one here? I had quite a back firing problem before this rebuild, and had cleared the exhaust side from being the culprit, so wonder whether this might help.

Cheers Dazza

PS I do have a photo of the bit where I put the "O" ring, so if needed I will battle through posting it

[Dazza57]

Thanks everyone for the clarification, seems when ever I do something to this beautiful beast I learn something more. Of course it certainly helps when the people on this site share their vast amount of knowledge so freely with us FJ newbies.

Cheers everyone, Dazza

[FJ1100mjk]

No O-rings on the carb bells...

True statement. No o-rings needed on the bell side, but I believe Dassa57 is referring to the "spigot" end of the carb.

[ELIMINATOR]

OK, no one else has asked. Why were the parts in the fridge?

[Harvy]

OK, no one else has asked. Why were the parts in the fridge?

Because Randys parts are pretty cool!   

[Dazza57]

I keep all my rubber bits (lol) in the fridge because of the hot climate up here, also dehumidifies, so keeps the rubber in better shape longer, so I am told. We do it with our speargun rubbers, so that's where I got it from.

[Dazza57]

First up, thanks Randy and Rich  for setting me straight on the O rings.
Well the carb rebuild saga continues. Checked and adjusted the valve shims, only 3 required changing. Put in new spark plugs. Completed reassembling the carbs and put back into the bike.
Got everything ready to do a synch with the motion pro, and found that the blue liquid is full of bubbles, so ordered some replacement fluid.
Got the motor warmed up, started first go with no choke, and when I did the blip test it was hanging and only slowly coming down, so closed up the pilot screws, the ones closest to the engine (that's what they are called in the Clymer manual), so they are now at 2 full turns out from seated. Blips OK now. Seems to idle OK without the synch, so took her for a run.
Well all seemed OK til I gave her a handful, and she started popping and stuttering like she wasn't getting enough fuel. Was OK when only slowly accelerating to about 5k, then I could hear the starving starting.
When I put the carbs back together I set the float levels with calipers, 22mm. All the jets from Randy's rebuild kit were exactly the same size as what I took out of them.
The only things that have changed are the float level and replacing the paper air filter with a K&N filter, but I wouldn't have thought that would have changed things so much. Also changed out the fuel filter.
The one big plus is that the back firing has gone, suspect the inlet manifolds were cactus, which I had also replaced.
Can anyone suggest where I might start to fix the apparent starving? Do I need to set the floats higher, or is there something else I have missed? Would I be advised to do the fuel level check before pulling the carbs out again (not looking forward to that, although I think I have found some better ways of doing it after the first time)
As ever, all help much appreciated.

Cheers, Dazza

[andyb]

Thanks Rich for pointing out the different between a screw and a jet

Doublecheck the fuel line routing if you've recently been in the carbs and are having possible starvation.  Possibly a stuck float, but mine always stuck open, not closed.

[Dazza57]

OK, not many responses over the weekend, too many more interesting posts
So I've got this problem, rebuilt carbs etc, not much has really changed. Bit more diagnostic info (wow big words for a Monday night, whew!)
Yesterday, I tried checking a few things without taking the carbs off.
Fuel line to the carbs OK, no kinks.
Tried to do the carb fuel level test with some clear tube, even with the engine running couldn't get the fuel level to come up into the tube only did #1 carb, maybe should do the others as well?)
I did set the floats with verniers at 22mm. Set the balance as close as could be by eye (still haven't balanced, don't think this is the problem, but correct me if I'm wrong)
So the problem:
can increase revs slowly in gear right up to about 6k, and all good, then starts to splutter and fart. If I do the same thing with load, it starts to immediately splutter etc, for me it really sounds like it is starving for fuel. A handful of throttle and it immediately starts stuttering, no power, just sick sounding.
OK, observations, yesterday, fuel pump did something different. Before, it used to tick when I turned on the ignition, yet this time it ticked more loudly, then stopped (which it used to do, stop that is), I started the engine and it started again (the ticking) Today I tried the same test, but the ticking wasn't nearly so loud.
Starting to suspect the fuel pump, but after checking Randy's site, I see there is also a fuel pump point set.
Can someone tell me whether the point set is separate to the pump?
To get this all into perspective, I have planned a tour down south on  Effy in 4 weeks time. If I need to order parts from Randy then I only have a short time to get it all happening.
I have had 2 suggestions today on possible causes of my problems.
1. spark plug caps arcing
2. too rich? (can't see how this would happen, exactly same jets all through, only change was the K&N filter and higher float levels measured by vernier)
3. Question here, I used slightly over the half amount of oil for the K&N filter, would this have as much influence?
4.Coils dying?
I know someone has  an answer out there that will help me get away on my holiday on Effy, just need to find it quick, please  really stumped

Dazza

[FJ1100mjk]

Dazza57:

Sounds like you may need to pull the carb bank. Again.

I re-read your previous posts, and I can't see where you actually did set the fuel levels properly in the float bowls. You mentioned that you couldn't get the fuel into the clear tube to begin with, and could only do #1 carb. When you had your carbs apart, did you make sure that the drain openings were clear, so that when you loosened the drain screws, fuel would flow out of the bowls? If they are plugged, that would be a reason no fuel would go into the clear tubing for checking the float bowls' fuel levels. I have found that just doing the float height adjustment is a starting point, but the clear tube to check the fuel level in the carbs' float bowls is a must. And don't be suprised if the float height adjustment varies my a marked amount to get the fuel levels within specification either.

One last thing, did you try running the bike with the gas tank's cap loose (or open, but not with a lot of fuel in the tank, for obvious reasons)? It's a long shot, but maybe your fuel tank's cap is not venting fast enough, and you're drawing a vacuum in your tank, which would cause fuel starvation too.

Marty

[movenon]

Here is some fuel system information for the 89 -93 FJ's.

OK, as a test you might run an 8mm fuel line directly from the petcock (bypass the fuel filter) to the carb inlet (you will need a few feet of fuel line and a barbed splice). Unplug your fuel pump wiring. And see if it runs any better. Now without a fuel pump at some point it will starve out so don't be alarmed. But you could get a couple of test runs. When was the last time the fuel filter was changed ? If you look into your fuel tank is it fairly clean looking ? If it is "crappy" inside the tank then be aware there is a small filter screen inside the tank at the petcock. Just something to know about.

With the above hose and fitting you will have an emergency fix for a bad fuel pump while in the outback.... Only use this for an emergency or a test....... If you use this for an "emergency kit" then also buy a cheap manual turn on and off valve. So you can shut the fuel off for an overnight stay or store it until it can be repaired properly.

As mentioned by FJ1100mjk you can get a vacuum lock in the tank because the vent flapper can stick shut. A simple test is to just crack open your fuel tank filler and let atmospheric pressure work for you and see if it clears up. Usually shows up after running down the road for a bit, sucking fuel out of the tank with no air coming in to replace the volume it will eventually slow the fuel flow down. More of a problem with gravity feed systems but can happen with any FJ.

The points your are referring to are located in the end of the fuel pump. If you need to replace the fuel pump there are a number of non stock, after market pumps that will work for 50 to 100.00 USD. Randy at RPM also has a pump that will work.

Here is a post on a KTM site that shows you what the points look like in the Mitsubishi fuel pump and one of the options to replace it with.

http://www.ktm950.info/how/Orange%20Garage/Engine/fuel_pump/facet_40171/facet_40171_install.HTML

http://www.youtube.com/watch?v=4

Just for info this shows you the points in action. The pump is used in many different bikes. What varies a bit is the inlet and outlet locations.

http://www.youtube.com/watch?v=77S2VVLupTY

If it is the fuel pump then be aware that the pump itself has 3 areas of fail er. the points, the diaphragm, or the motor. What I am saying is that the points might not fix it.

George