New Mixture Screws

[chewy999]

Today I put new 'mixture screws', item 5 here - https://www.cmsnl.com/honda-gl1100-gold ... wcIYuSG99A into the carbs, with the carbs still on the bike.

Started by taking off the false tank and manifolds on one side to give plenty of room to work in.

New Jets 1.jpg (99.54 KiB) Viewed 253 times

Then placed a towel over the cylinder head to stop stuff falling into the chamber. The parts for the screws are VERY small. Then using a right angled adjusting tool, unscrewed each screw.

New Jets 2.jpg (135.89 KiB) Viewed 253 times

I know some of you find these tools awkward to use, but I find if you get it on as square as possible, then just apply a little downward pressure at the opposite end from the working part, it holds in position while you turn the adjuster either way.
Then the fun part. Chances are when the screw comes out, the washer and O ring stay inside the carb. In fact, of the four I did today, only one washer came out with the screw!

I used a piece of copper wire with a small bend in the end to fish the washer and O ring out. It worked pretty well apart from the O ring in no. 3, which took about 10 minutes to come out. Still easier than taking the carbs out.

New Jets 3.jpg (92.71 KiB) Viewed 253 times

Prepared the new screws, making sure the spring goes on first, followed by the washer and finally the O ring.

New Jets 4.jpg (127.73 KiB) Viewed 253 times

Then carefully insert the screw into the hole and using the adjusting tool, tighten the screw carefully until you feel a slight resistance. DO NOT TIGHTEN any more or you will damage the end of the new screw.

New Jets 5.jpg (103.06 KiB) Viewed 253 times

Different years give different figures as an initial setting. The 1980 figure is 1 1/4 turns out, I did 2, but all of the screws should be the same.

Refitted the manifolds and dummy tank and after cleaning and checking the spark plugs, I fired her up. Seemed to idle a lot better, but didn't get chance to test ride it, but pleased with my efforts. As far as I know, actually didn't break anything else today, which is unusual for me!

[gltriker]

[5speed]

[desertrefugee]

What was wrong with the old screws?

[chewy999]

What was wrong with the old screws?

From what I could see, probably not a lot. It was one of those jobs I just wanted to do, like my posts saying I changed the coils and spark units. Each job I do does seem to improve things, but not sure why. I will say that my bike seems to idle a lot better now, but still above 1200 rpm, or it just stalls.

[mikenixon]

chewy999 -- Try 2 1/2 turns, even 3 since you likely have some internal issues as hinted at by your mention of your performance. But no further.

[RB]

Yep, should idle at well under 1200 like around 950..I'd say you have idle jet issues..

[chewy999]

chewy999 -- Try 2 1/2 turns, even 3 since you likely have some internal issues as hinted at by your mention of your performance. But no further.

Thanks for the advice Mike. Will do!

[chewy999]

Undid the screw another 1/2 turn, then another, so three turns altogether, and each time set the revs to 1000 rpm. When the bike had warmed up, seemed ok, but wouldn't say it was comfortable, if you know what I mean, but it kept running. 1000 rpm is within limits according to my (Haynes) manual.

One thing I noticed was that with each screw set at 3 turns, you could see the end of the screw at the entry point, didn't notice that with the old ones, so does that sound right?

Finally, which is the idle jets on the diagram in post #1? May consider changing those too.

[robin1731]

snip........................

Number 22.

But what year carbs are you working on? 80-81 had press in jets. 82-83 had screw in jets.

.

[chewy999]

snip........................

Number 22.

But what year carbs are you working on? 80-81 had press in jets. 82-83 had screw in jets.

.

Without checking, I believe they are 1980 -81 carbs.

[mikenixon]

Undid the screw another 1/2 turn, then another, so three turns altogether, and each time set the revs to 1000 rpm. When the bike had warmed up, seemed ok, but wouldn't say it was comfortable, if you know what I mean, but it kept running. 1000 rpm is within limits according to my (Haynes) manual.

One thing I noticed was that with each screw set at 3 turns, you could see the end of the screw at the entry point, didn't notice that with the old ones, so does that sound right?

Finally, which is the idle jets on the diagram in post #1? May consider changing those too.

There is a rather involved explanation for why 3 turns. But I'll shorten it. Basically, a perfect GL1100 will work fine at 1 1/2+. But 2 1/2 is needed in bikes with engines that have never been rebuilt. And 3 turns is useful for engines that have not been rebuilt *and* whose carbs' idle circuits are not completely clear. Oh, and at 3 turns you are at the limit of the spring's ability to keep tension, so though you may be tempted, go no further. And, consider this 2 1/2 to 3 turns a band aid fix, a workaround. You can keep the adjustment if you like, and many do, but everyone should know that it is making up for other issues.

The idle jet is pressed in before 1982, but you should still make an effort to remove it. This is done by carefully threading its head (only 4mm deep) and jacking the jet out. Once you get the jet out, you will be glad you removed it. Rust, varnish, all kinds of crud will be packed in and around at least some of them, if not all. You can reinstall the same jets once cleaned and vetted with a guitar string.

[chewy999]

Thanks Mike for the info. I did look at the overhaul procedure for 1100 carbs in the Guru's corner, and there is a link to a video showing how to remove the pressed in idle jets. I appreciate you saying I should try to remove them to clean them properly, but I can predict exactly what will happen.
The first one will fall out, the next two will come out with a little force as per the video, but the last one will be stuck as if it were welded in place! That will then end up wrecked with no replacement available!
Now the riding season is here, going to leave it for now, but then have a rethink for the Winter projects.

[robin1731]

But if the pilots are plugged, they usually are, it will never run right. Follow the procedure Mike suggested and they come out pretty nicely. That is the way I do them.

.

[Track T 2411]

I did this on my last set, and it worked nicely. Are there replacement o-rings available for these jets?