gt750k rough off idle

[cabz]

Well I finaly got to ride the old girl today first of many shakedown runs
while riding I noticed that the bike has a nasty miss at anything below 2500 rpm. I was thinking it was the carbs but I couldnt seem to isolate it .
I pulled the right carb and checked it out and it was clean as a whistle .I was thinking the poits where cloged but that turned out to be wrong .
No vac leaks and the points I had just set . any ideas what could be wrong? also what would Ping sound like on a two stroke? theres so much noise to these things it is hard to tell there seemed to be a ting noise when I accelerated hard

[cabz]

P.S when riding if I cracked the throtle she would smooth out ( no miss ) and flat get ta goin Mains are just fine I figure

[rngdng]

If it's rough at small throttle openings, it's likely the pilots or the air passages clogged. The pilots are in control at little to no throttle, and the air mixture is critical.

Of course, there is a possibility that the ignition is also involved. For instance, if the battery is very weak, your alternator may not put out enough voltage to produce a sufficient spark. At high rpms, it might be OK. You have alternator brushes, plug caps and wires, coils, points, and condensors to worry about. Check all of these by the book, and correct anything that is wrong, such as plug cap resistances, poor ground connections, etc. My Buffalo was running fine on a long distance ride at Deals Gap one year, and we stopped for a second, so I killed the engine, and it wouldn't start anymore. I finally got it to kickstart with the lights turned off. The problem was a weak battery. When I turned on the headlight, it wouldn't run.



Lane

[cabz]

Well day 2 after checking the right carbs pilot and resetting the points it seems to run a hair better. still kind of bucking and missing at lower off idle throttle . I am used to the closed throttle bucking with the vm carbs but on the other side it's kinda agriavteing.

I am gonna pull the air box and recheck the other pilots and go from there . the idle still runs about 1200 rpm and slowly dies out but it seems like the more I ride it the better it gets .

on a side note does anyone know the part number of the uni filters that will work on the vm carbs , I dont think I have the paitince to put the old air horn back on again.

[Suzsmokeyallan]

Cabz did you do a compression check on the cylinders???
Also if you cleaned the carbs and can be sure the pilot circuits are clear that should rule out a problem there.
Run through it carefully again rechecking all the areas as Lane suggests and try some new condensers while youre at it.

[cabz]

Cabz did you do a compression check on the cylinders???
Also if you cleaned the carbs and can be sure the pilot circuits are clear that should rule out a problem there.
Run through it carefully again rechecking all the areas as Lane suggests and try some new condensers while youre at it.

one of the first things I did was a comp check, I got an even 120psi on all 3
I am unsure about the pilots becase the carb bodies are so oxidized in side I figure it wont hurt to try and check them once more then I'll go over everything else.

[cabz]

If it's rough at small throttle openings, it's likely the pilots or the air passages clogged. The pilots are in control at little to no throttle, and the air mixture is critical.

Of course, there is a possibility that the ignition is also involved. For instance, if the battery is very weak, your alternator may not put out enough voltage to produce a sufficient spark. At high rpms, it might be OK. You have alternator brushes, plug caps and wires, coils, points, and condensors to worry about. Check all of these by the book, and correct anything that is wrong, such as plug cap resistances, poor ground connections, etc. My Buffalo was running fine on a long distance ride at Deals Gap one year, and we stopped for a second, so I killed the engine, and it wouldn't start anymore. I finally got it to kickstart with the lights turned off. The problem was a weak battery. When I turned on the headlight, it wouldn't run.



Lane

I have abrand new batery and the alt puts out ok . I also have a new rectfier and all the wiring connections on the bike have been cleaned and dilectric greased , I have rechecked all the grounds and they are good as well.
Now the points and condensor are old , I was hopeing to hold off on replaeing them for a bit they dont appear to be bad . but I will double check the condensors anyway

[rngdng]

If your carbs were as badly oxidized as the Kaw H1 that I'm currently working on, you may have lost enough material in the passages to make it impossible for the bike to run well. I had to give up on the carb bodies and get another set because there was a lot of visible pitting in all of the passages. After cleaning, the needle jet would rattle around even after tightening the main jet. Not too good!

Just another thought.


Lane

[cabz]

If your carbs were as badly oxidized as the Kaw H1 that I'm currently working on, you may have lost enough material in the passages to make it impossible for the bike to run well. I had to give up on the carb bodies and get another set because there was a lot of visible pitting in all of the passages. After cleaning, the needle jet would rattle around even after tightening the main jet. Not too good!

Just another thought.


Lane

thats what I am praying isnt the case, I will popem apart one more time and see.if they are toasted I'm gonna find a good set of BS carbs to slap on and be done with it
I did however land a complete points and condensor set off ebay for $30 bucks hopefully that will help out some

[TLRam1]

I think I have a set of carbs you can have for shipping, not sure of the condition. I can look if you want and shoot you photo if I can locate the carbs. Now I don't remember what carbs you have these would be the CV. I have to read your post again.

[cabz]

I think I have a set of carbs you can have for shipping, not sure of the condition. I can look if you want and shoot you photo if I can locate the carbs. Now I don't remember what carbs you have these would be the CV. I have to read your post again.

the carbs I am fighting right now are the vm's the non cv's but If I cant make them work right I'll take you up on that
I ran the BS carbs on another 73 and never had any issues with them