Topic: Carb sync issue

[sky56]

So I'm syncing my carbs today and for the most part everything went smooth. However after adjusting them repedetly I could not get carb number 1 to sync up like the others. I cleaned them very thoroughly and I'm not getting any leaks. I snapped a pic of what the carb tune looked like. Also I used my infa red thermometer in the same spots on my exhaust pipes (I'm running 4 individual pipes) and pipe 1 was running 260 pipe 2 was 120 pipe 3 was 120 as well and pipe 4 was 240. If anyone has anything thoughts on why this is I'm all ears. I'm running NGK D8EA plugs and all 4 are gapped to 0.7. I'm also running DOHC coils. Hope this helps. Thanks for the help in advance

http://i584.photobucket.com/albums/ss286/skylong569/62ea2a36.jpg

[nancy]

Check your points are ajusted right and not badly pitted. Pots 1 & 4 being hotter - maybe coil or points and you have a set of points and a coil - for that 2 pots..right? Can also be just coincidence. Check float levels are consistent.

[WarwickE36]

When you say cleaned thoroughly, were your idle jets squeaky clean?  Can you see light through them?

I did a clean on mine ran the bike for a couple weeks (with a rusty gas tank)...  When I finally shelled out $70 and replaced the petcock (because the PO broke the hex piece off the bowl and glued it back on) i noticed there was NO screen in the petcock.
Needless to say there was rust in my carbs again and 1/4 were semi-plugged and running lean and HOT.

I pulled the carbs re-cleaned everything, set float heights (which i didn't know to do the first time), and synced the carbs up again.  runs great now.  Idles mint at 1,000Rpms, even heat at all headers.  Much cooler on eacah header than before... wouldnt want to hold my hand on it but just touching it real quick doesnt scald me like it used to.

[sky56]

I might end up recleaning them but they were looking good when I put them back together and I could see light through the jets. Thanks for the input so far guys

[Johnie]

Try syncing all the carbs to #1. See if you get some response that way.

[Gregorymoto]

What do the plugs look like?

[Celco]

with the morgan carbtune, also try flipping the carbtune upside down.  I see all of your bars are very low.  Flipping it takes out the gravity on the equation and the carbtune is a little more precise on the small end of the pressure spectrum. (the bars are spring loaded so they will all "zero out" when upside down).

Try swapping vac lines too, you might have a leak in the hose or something too.

[wrenchmuch]

+1 on a leak somewhere . When you blip the throttle does #1 still sit at the bottom? When you hook up a light to check timing is 1-4 advanced more than 2-3 . The temp difference is strange . I think dohc coils are low resistance . 2-3 ohms ? This will cause increased arcing at the points and shorten their life . If the spark voltage is higher widening the plug gap might help smooth out idle roughness . I gap plugs at .040 in. with my Dyna 3 ohm coils and Dyna S trigger .

[sky56]

Ok we tried the flipping of the carb tune and all the meters flow. We tried switching the lines too. There was good vaccum on all but number 1 (it had vaccum but it was weak). When I hit the throttle all the meters jumped but number 1 stayed a little lower

[wrenchmuch]

Low vacuum can be from a incorrect valve adjustment (valve always open ) . Burned exhaust valve . Head gasket leak . Intake manifold not sealing properly ( most likely ). Slide on number one could be way off to the others ( also very likely ) . I think you should pull the carbs , bench sync , and check the manifolds at he same time . I have new manifolds but the old clamps allowed them to leak . I bought stainless gear clamps from West Marine (they are a little narrower than standard gear clamps ) and now they seal fine >