O'rings for throttle shaft

That worked. Runs really rough, but does run. Now to figure it out to run smoother.

 

How about spark?

 

I felt the headers after running it for a little bit. One was cold.

 

your bench sync with paper clips is only to get it close, now you need a running sync to smooth it out.
don't worry about the cold header right now, use a running sync to get it a little closer, the missing cold cylinder might just come to life

 

Reset the float height, and she starts right away. Still a little rough, but she started. Still need to sync, but tomorrow is another day. Still waiting for brakes to show up, but hopefully tomorrow.

 

So, I started the bike last night and it was really rough. Again I checked the spark, and it looked decent. Took the plugs out, and one looks brand new. Did a compression test, all at 120 cold. Changed the plugs around and still the same plug looks clean. No heat on that exhaust either. Bad plug?

 

Did you do the running sync yet?

 

Not yet. Don't think it would make any sense to sync 3 of 4.

 

Do you have a spark tester to check the lead to the cold plug? Or ground it to the engine and turn it over, make sure it’s sparking.

But like Polock said, do the running sync as well

 

I did a spark test off the engine, and there is spark on all four. I'll try to sync this weekend.

 

Are the throttle shaft o rings made of the same material as the engine o rings?

 

Buna is the type. I believe they are a high temperature tolerance.

 

Perhaps the engine ones are Viton because they can deal with higher temperatures than Buna ones.

 

While I'm waiting for my brakes, sync kit and new throttle shaft seals to arrive, I decided to drill out the air screw. It turned out that it was already done, so I checked them all to make sure they were at 2.5 turns out and saw that one was missing. I forgot that I broke one of the float posts off and had a used one shipped. That might have been the cause of my rough running.

 

i would think so

 

Found another problem. I was checking the carb bowls, and #3 was plugged in that little drain at the bottom. Soaked them last night, and blew them out today, but it is still plugged. Other than soaking them again ( I am right now), what else can I do?

 

steel guitar strings work good to poke in there. it might take a while but you'll get it.
the little red tube on a can of brake cleaner helps

 

I had a long sewing needle in there, but I just can't break through. The bike sat for 27 years with gas in it. I have been spraying the crap out of it. It is soaking again.

 

you may need to get a drill bit and make a new hole

 

I had a very small bit in there and I was turning it with my fingers, but couldn't get spray to flow through.

 

If you have a syringe without the needle you may be able to put it into the hole in the bowl the brass tube goes into just watch it doesn't get stuck. Force some acetone or something like that may dissolve it.

 

Never thought of acetone. I don't think I have a syringe. I'll try to find something.

 

You want to unblock it without widening the jet. Solvent will do that hopefully. Good luck.

 

three out of four will start it !

 

Sound like one of those crippled triples the racers use lol.

 

It is the original bowl. Nothing much on the bike has been changed.

 

I used to put carburettor jets in a pot of boiling water and leave them for 5 minutes. That might work.

 

I read somewhere that racers used to disable one cylinder on four cylinder bikes that's why they called them a crippled triple. Don't know if it's true or just a joke?

 

I got some acetone in the hole now. If that doesn't work by the morning, I'll try boiling the bowl.

 

#80 drill bit glued into a red spray tube

 

Would I find a #80 bit at a hardware store, or is that a special order?

 

may be but you wouls have to ask. maybe an auto parts store. I got mine from ebay . also maybe a welding torch cleaner may work and be easier to find

 

We'll, I got it boiling. See if that works. I do have a very small drill bit that fits in both holes with a little wiggle room. I'll try that if boiling doesn't work.

 

Drilled through the crud. Made the pin hole just a little bit bigger. Hope that doesn't make another problem.

 

Hopefully it will be ok.

 

Is that port for the choke?

 

Yes the fuel goes through the jets in the float bowls up the brass tube and exits in the carburettor on the engine side for cold starting.

 

Finally my brakes came!

 

Brakes are on. Front are grabbing without me squeezing the lever. Did I do something wrong? Is there something I should check?

 

Check the tiny pinhole in the brake reservoir. May be clogged and not letting the pressure release.

 

Forgot to depress the brake cylinder. Everything is ok now.

 

Sorry for bouncing all over the place. When I checked the aircrews, 1 and 4 were 2.5 turns out. 2 and 3 were 3 turns out. I set them all to 2.5 turns out. Is that going to make a difference?

 

quick snipet from link below

The word "synchronization" means "getting things equalized" between various component pieces. Are you setting each individual carb to the exact same specs?----the same idle mixture screw setting, the same throttle valve (butterfly) opening during this procedure?
...........You will have different settings on all four carbs when you're done with the procedure..........

WHY?

Because YOU'RE NOT "SYNCHING" THE CARBS!


https://www.xjbikes.com/forums/threads/talkin-tech-various-thoughts-on-various-issues.14608/

 

a color tune or checking plug color will tell if it starts to run odd readjust the mixture screws

 

Stupid question, I am adjusting the air mixture screws when I sync?

 

you set the mixture screws then sync if you have aa color tune
you check and adjust mix again then resync. if it needed more adjustment.

 

I only have a homemade manometer. I don't even know if it works right.

 

What color tune do I need to get? I think they come in different sizes.

 

to match your spark plug thread size xj4ever sells them

 

Measured the valves tonight. I think I did it right. I haven't been able to get the shims out yet, but tomorrow is another day.

Intake 1 - .04mm Exhaust 1 - .13mm
Intake 2 - .08mm. Exhaust 2 - .15mm
Intake 3 - .06mm. Exhaust 3 - .15mm
Intake 4 - .08mm. Exhaust 4 - .10mm