Sync Adjustment Screw Holes

[cowboyup3371]

Does anyone know what the thread pitch is for the sync adjustment screw holes on the 550 carbs? I know it's a M5 set screw but the pitch looks finer than a .80mm.

I have had problems getting Charmayne's 550L carbs to sync starting with a stuck nut on the adjustment screw for the same carb a few weeks ago. After replacing it and redipping the carbs for other reasons, I found the hole is stripped out completely. I'm hoping I can helicoil it but if not I'll be looking for another carb body.

[Brendan W]

http://www.cmsnl.com/products/bolt_071300510b/

Same part number as the 850 and mine is a 5x10 with what looks like a 1mm pitch.

[cowboyup3371]

Thank you Brendan but I mean the one on the carb itself to adjust the sync not the vacuum line ones

[Brendan W]

1360747070 nut
1360547080 screw

If you can decipher these parts numbers ?
They look special.

Good news is it looks like it was used on nearly everything

http://www.partzilla.com/parts/detail/suzuki/SP-13605-47080.html?gclid=CNvn0dLx4c4CFaK_7QodeS8ASA

[cowboyup3371]

Thanks, actually did a quick search online, why don't I ever do that first, and found its a .5mm thread (Steve confirmed this too). Unfortunately there isn't a helicoil for that size so I'm off to find a set screw in the coarse thread to fix

[Dogma]

Maybe you can get a shop to braze it shut and re-tap it?

[JTGS850GL]

Not sure what the pitch is but I'm pretty sure you wont be finding a heli-coil that will match. It's a very fine pitch for a reason. You need small adjustment increments and the ability to keep it in place. Don't think you're going to fix it with some bandage fix. Your best bet is to replace either the aluminum lever that's stripped or the entire carburetor body.

Which carb is bad? If it's the number 2 carb then there's a roll pin that can be pressed out to remove the lever. The other two are part of the shaft assembly.

[geol]

Thread pitch is .5

[cowboyup3371]

All, I'll be looking for another #2 carb body for her bike then. Wanted post will be up shortly

[JTGS850GL]

Number 2 carb is the one that can have the lever replace by simply pressing out the roll pin. I may have one for you if you need it. If you end up picking up an entire body, then make sure it's from a 550. The main air jet needs to be 1.6 and only the 550's used that size main air jet.

[chef1366]

Tap it to an available fine thread screw and a lock nut.

[cowboyup3371]

Tap it to an available fine thread screw and a lock nut.

I wondered about that Chef but wasn't sure if an M8 would be too big or not; would it work or can I even go for a m6 size?

[Dogma]

A coarse M6 tap drill is 5 mm. I happen to have that memorized. So a fine thread M6 tap drill is slightly larger than 5 mm.

Edit: I did some Googling. M6x0.75 tap drill is 5.2 mm. Taps seem pretty cheap. McMaster has a few length options for socket head set screws in steel, and "low strength" nuts, not too expensive. Disappointingly limited material options though.