Carb sync screw

[knotzilla]

Hi, I have a 1980 gs850 and I was wondering how to get access to the carb sync screw for # 2 carb. I made up the special tool that consists of a 8mm socket welded to a length of 1/8 npt pipe in which a long screwdriver is inserted inside the pipe. The problem is that the brackets for the throttle and choke cables that attach to the top of the carbs get in the way of getting at the adjustment screw. Does anyone have a solution? Thanks Ted

[Cajun Cycler]

Have you tried removing the tank to reach those screws? If you can you can attach a long piece of fuel line to the bottom of the petcock, put the petcock on prime, mount the tank somewhere high enough and out of the way and then sync the carbs with the engine running and the tank out of the way.

[knotzilla]

Yes, the tank is removed. It looks like moving the choke lever bracket out of the way might give me enough room. Does anyone have a problem with # 2 carb sync screw or is it just me? Thanks Ted

[Cajun Cycler]

Mine is 79 with V/M carbs. Yours should be CV carbs. Different animal...

[bwringer]

Yes, it is a royal PITA to get to. I have a 1983 GS850 -- same carbs.

I have the same sync tool, and I just sorta get to it at an angle. Usually, I get the outer tube with the socket and jam it on there, then drop in the screwdriver part. It takes a bit of finagling, but it is juuuuuuuuust barely do-able.

I've heated, bent and ruined several 8mm wrenches in an attempt to make something else that can get in there and reach that furshlugginger lock nut, with no success.

Speaking of carb sync, someone a while back mentioned that they had converted their sync screws to some sort of spring-loaded arrangement that allowed you to turn them, but kept them from changing position under vibration. I think some modern bikes have these.

Anyone had any luck with something like this? It sure would make carb synchronizing a lot easier. The most challenging (impossible) part of the whole exercise is snugging the locknuts without moving the screws.

[bwringer]

In re-reading your original post, it looks like you have a homemade version of this:

http://www.motionpro.com/parts/tools/product/carb_adjusting_tool/

I have this tool, and as I mentioned, it is just barely possible to finagle the socket onto the locknut at an awkward angle.

The 1/8" NPT pipe used in your homemade tool is significantly thicker than the very thin wall pipe used to make the motion pro tool, so that's why you probably can't get it to work at all.

IMHO, it seems that re-engineering the screws so they're adjustable but will stay in place would be a better solution all around.

[knotzilla]

I've downloaded the modifications for the spring loaded clips. I didn't modify the screws. I am kind of leery using the clips for the sake of the sync screws vibrating loose. I know that the locknuts will not loosen. I have the tank on the bike ready for the next good riding day. Next time I have the tank off I will take another look at #2 sync screw to figure out a better way of getting access. Thanks Ted

[DimitriT]

The throttle bracket on my 82 550L can be removed to allow access to the screw. I can remove the bracket without having to unhook the throttle or choke cables. I don't know if your bracket is similar to mine, though.

J.C.Whitney sells a tool just like you describe for this task (www.jcwhitney.com).

BTW, I just resync'ed my carbs after removing them for an inline filter install and a recent valve re-shimming. I noticed that one of the nuts had come loose and the adjustment screw had nothing keeping it from moving!!! After the synch was done I made sure everything was tight and applied a drop of blue loc-tite to each screw/nut. The sync job is a PITA. Keep your adjustments small and watch that you don't overheat it (take short breaks after a few minutes to let it cool off). Even with a fan on it, it will heat up. I love the rock steady idle you get from properly sync'ed carbs.

[knotzilla]

After looking at the advertisement for the sync tool, I agree that that the 1/8" npt pipe could be too thick. I'LL try my homemade tool again and notice where it contacts an area where it could prevent it from accesssing the locknut. I"ll then grind the area on the tool to make it a smaller diameter at that point. Maybe also the throttle and choke brackets could be modified to make room for the tool. I'm the type of guy who likes to fabricate special tools and things instead of forking out money needlessly. Call me cheap I guess. Thanks Ted

[knotzilla]

The sync tool made from 1/8" npt pipe will work. By removing the screw holding the choke cable bracket that is attached to #2 carb and moving it to the side will gain access to the screw and locknut. I saved $20 American or $100 Canadian (Kidding). Ted

http://i42.photobucket.com/albums/e326/knotzilla/SyncTool.jpg

[wolfie]

I just did mine last night. I too ruined an 8mm wrench. That was a waste of time. I have a 1/4" socket driver (screwdriver type) that would fit, but the choke bracket got in the way. I ended up cutting 1/2" of of the handle to get it to work.

[knotzilla]

Yes, weld a 1/4" drive 8 mm socket on the pipe. A 3/8" socket is too large. Ted

[earlfor]

Remove one screw from the bracket and pivot it to the side allowing access.
Hint...remove the inside screw. :-)

Earl

Hi, I have a 1980 gs850 and I was wondering how to get access to the carb sync screw for # 2 carb. I made up the special tool that consists of a 8mm socket welded to a length of 1/8 npt pipe in which a long screwdriver is inserted inside the pipe. The problem is that the brackets for the throttle and choke cables that attach to the top of the carbs get in the way of getting at the adjustment screw. Does anyone have a solution? Thanks Ted