Bike won't idle - suspected carb issue

I was wondering, is there a way to bench synchronise a set of TK26 carbs (i.e. get them roughly right with the carbs off the bike)?
I need a rough sync before I can do a proper one, as I can't get the project bike to idle at all at the moment (rebuild error probably).

Any particular method or things to watch out for? I don't think the ball bearing trick would work as there is a lip on the carb on the air intake side.
Do you think I could get away with using a feeler gauge for this? And any particular settings for the idle screw while this is done?

Thanks in advance

A thin piece of phone wire makes a good gauge. Set them all using that. Start with the one carb that's not adjustable except by the idle adjustment screw then set the rest the same. Leaky carb holders will give a unstable idle.
Steve

We use a small straightened paper clip to bench sync sometimes.

Good Ridin'
slmjim & Z1BEBE

I use a piece of 20 gauge copper wire. It measures within the stated spec. You can buy it at Home Depot in the picture frame wire section. It's sometimes called artists wire.

hardrockminer wrote: I use a piece of 20 gauge copper wire. It measures within the stated spec. You can buy it at Home Depot in the picture frame wire section. It's sometimes called artists wire.

TRhat's a very good idea. Much less chance of nicking the bottom of a slide or idle orifice.

Good Ridin'
slmjim & Z1BEBE

I do them by eye with light shining through, when they are even you can adjust them all at once to spec with the idle screw.
The real tell is when you install them and set the true idle

+2 on the phone wire. You pick 1 of the 6 strands and its close to specs.

Stick the wire in the carb opening and close the slide on it.

Then adjust the idle adjustment screw on top until you are barely able to move the wire freely. It should rub on the slide bottom.

Repeat for all the carbs.

This will get you close enough to be able to start the bike and get to idle and then do a decent sync with a sync tool.

Thanks for all the helpful replies chaps. Really useful stuff. I got myself a suitable bit of straight wire, and did them all. No problem at all. Not as precise as ball bearings, but surely close enough.

Anyway, that wasn't the end of my troubles LOL.
The bike runs (the engine is good) but it still won't idle, and I think I know why. I took off the carbs again and had another look at the pilot jets. They are completely stopped up. You can't see any light through them. All I had done to them was blast them in STP carb cleaner and then boil them in vinegar (this usually does the trick for me), and then I'd put them back in. Mistake. I should have stared down them, because if I had done, I would have seen them completely bunged up.

Bits of wire won't unblock them (I've tried) and I don't have a drill bit small enough to drill them out. I tried looking them up online (they're TK26 #32) but they don't seem to be available to buy anymore. I tried hitting them with a butane torch but that didn't work either. Any ideas? Looks like 5 years' worth of rock-solid varnish have turned these pilot jets into simple stoppers/plugs.

I use a guitar string end to clear them.
Steve

Here's a site about TK26 jets. This link has a link to where to get jets. Hopefully they still have them.
s3.amazonaws.com/gpzweb/TK26mainPage/TK26jets/TK26jets.html

Here's a link to the TK26 site.
s3.amazonaws.com/gpzweb/TK26mainPage/TK26mainPage.html#home

There are a few tools you should prepare before syncing the carbs on the bike. The site shows them in the maintenance link.
It also shows how to repair a stripped sync linkage, which is aluminum with fine threads, so they strip easy.

Thanks! These were really stubborn ones. I don't play the guitar so I tried resistors (from an electronics kit) instead. Didn't work - they kept bending. I ended up heating them to orange-hot over the stove, then quenching them. Desperate times, desperate measures, etc. This seems to have done the trick - I can see a hole letting in an equal amount of light through all of them now. I'll try fitting them and seeing if I can finally get the bike to idle with the choke off tomorrow when it's light.

One more question please, if you don't mind. The underside of all 4 of my TK26 carbs has 3 brass passages. 2 of these are holders for the jets, and you screw the pilot jet and the main jet into these. The third is a bit of a mystery - I can't see where it leads or what it does. My Haynes manual calls this passage a "secondary main jet - early type/main jet - late type", which would suggest that it isn't necessary. However, this website shows this hole stopped up and calls the stopper a "pilot plug":
gpzweb.s3-website-us-east-1.amazonaws.co...ge/TK26mainPage.html

I'm just wondering whether the absence of any kind of stopper there on the TK26 carbs on my bike might also affect the pressures and velocities of fuel going up through the pilot jets. I don't see how it could, but it's bizarre that that website calls it a pilot plug. Any ideas?

Please read the main page. It explains which have the plug and which others don't.

If you post your exact year and model with the letter-number designation in your signature, then I could assess whether or not your model should have the plug and intermediate jet.

Guitar strings are way stiffer than copper wire. Guitar shops will usually sell you one string at a time if needed.