CV 34 Polyester plugs

Those mixture screw on the top at the front - Spec is 2 turns out from lightly seated. I haave pods and 4->1 exhaust and find that 3 turns out works best for me.

When cleaning the carbs I'm not happy unless I can gently get a fine wire or nylon bristle down each hole I can find and finally blowing everything out with compressed air at the local filling station. Including the pilot jet like Link14 says. Did you take the idle screws out and check the screw, spring washer and O ring ? Also watch for the transition holes. To find them look into that end of the carb which connects to the motor. Open the throttle butterfly and look up. Behind the hole for the mixture are 3 tiny holes - transition holes and dirt or blockage here can cause stutter between 2 and 3,000 rpm. I must have cleaned my carbs 4 times before I found them.

Are you sure the problem is carbs ? and not spark or plugs or plug caps or plug wires etc ?

Good luck.

Thanks for the reply. I did see those small holes. I have the factory manual and did alot of reading up on these circuits to see what they were. (I actually thought they were fly crap when I first saw them...lol). I did not run a wire/bristle through, but did verify air flow through all the passages. I think I have my screws at 1 3/4, per WG. When we are talking turns, we are talking 360 deg rotation = 1 turn, right? The idle screws looked good, along with the springs and washers. 1 o-ring was beat up, but thats on the #4 carb and will be getting replaced once I have enough stuff to order from z1. I REALLY don't want to take these carbs off anymore... my inner two boots are rock hard and I actually cut my thumb good getting them on... I guess I could always quit being cheap and buy new boots .

As for non-carb related... I doubt it, but I've been wrong before. It does have new plugs and wires. WG mod to get good power to the coils, new battery, valves adjusted. Plug caps are original...I'll swap a cap with another cylinder. I just assumed it was a carb issue because I did have to clean them 6 times to get all the crude out from making my float needles leak.

BTW, how do your pods work on this bike? Did you have to rejet much? I might be interested in geting those in the name of asthetics and ease or removal... I know, they can cause more issues than they are worth at times...

For the transition holes I have a fine pin bent at 90 deg in the middle which I just poke each hole to make sure no obstructions and follow with spray carb cleaner and compressed air. Those holes are so tin yit's difficult to get anything in there.

If you have the pilot screws at 1 3/4 turns (1 turn = full 360 deg rotation) out then I would suggest backing out another 1/4 and if that makes an improvement then try another 1/4. You would be surprised how much difference a 1/4 turn can make

If the carb boots are old and hard they may be cracked and leaking. Theres a way to test by spraying carb cleaner or WD40 around them while the engine is running . Try a search here. A good seal on air hose to carb and carb to motor is critical.

If the plug caps are original then I would get new ones. Plug caps usually have some kind of resistor in them which will eventuaally break down. I test and replace mine every 2 or 3 years.

The pods and 4 into 1 were on the bike when I got it. I have upped the secondary main jet to 140 and the primary to 70. I know lots of members report issues but I dont have any. The bike runs well. I dont notice sucking sounds or have a problem with cross winds. I also dont ride in the rain so can say what would happen if I did. I have thought about getting an airbox and going for the stock look and might just do that one of these days. On the other hand pods do make getting the carbs on an off a snip

Thanks for the reply. For the other passageways you literally get the wire/bristle to go in one hole and out the other? I can just imagine how difficult it would be to get it to route around all the 90 degree turns. I'll have to give it a shot this weekend. I can't do much right now because the back and front wheels are off getting new rubber

I have some 50lb strain nylon fishing line which is good for the twistie bits and passages. Be carefull using a wire that you dont scratch and cause damage. There are probably a few holes and passages I could not get the wire or bristle or nylon the whole way through. I dont think I really got anything into the transition holes. .... but between the poking and spray car cleaner and the compressed air I kept at it until I was satisfied I have done the best I could. I have found in the past that if I tackled carbs in a half assed way I would only end up doing them again

Yeah, I hear ya on that one. I'll have to try the fishing line. I too had some reservations about using anything too sharp. I did verfiy that I had air coming out the transition holes and pilot hole, but I am taking them off one more time this weekend to ease my mind. However, I will try adjusting the air/fuel mixture screw first.

SO...I got alot...bear with me please!

Last night I took the wife for a spin. I figured it was a chance to adjust my idle mixture screws and see if that fixes anything. Well, no luck, but we still went for a ride. It started really hard and idled really really low.(less than 500). So I adjusted it up and we left. As the bike warmed up the idle started to hang. When we got home I adjusted the idle down, and bam, starting missing. Anything below 1500 rpm, either 3 or 4 would miss. At wide open throttle the bikes hauls, so I figure a pilot passage is plugged.

Today I had time to take the carbs off again. I took them completely apart and started to poke my torch cleaning tip around. I first made sure the passage way from the pilot jet (the one with the plug) to the pilot hole and transition holes. I cleaned the openings, got my wire as far in as I could and douched the heck outta it with carb cleaner and compressed air. I then made sure the passage between the pilot jet and main jet was clear. It's a big passage, so it was already clean. I then made sure the passage from the main jet to the inlet of the carb was clear (where the air comes through). I then made sure the passages to the dome of the carb where the diaphragm is was clear. After I did all of this, I repeated about 4 more times . I think my teflon tape might have caused more issues though. I think some of it might have been partially blocking off the passage hole between the main jet passage and the pilot passage. So, the parts carbs I have (I think off an '81) have a slightly different plug, and they were all snug, so they will be donated . One thing that is still bothering me is that nozzle or tube (depends which part diagram you refer to) under the main jet (the little one, #62). Looks like they should come out, but mine don't really look like they will. Anyway, they are sitting overnight because I ran out of time. I'm gonna repeat my steps today again tomorrow to make sure these things are clean. I haven't ran into any obvious smoking gun yet, but hopefully this will solve my issues.

BTW, when the throttle is closed, only 1 of the 3 transition holes are visible. Think this is about right?
Also discovered 1 of the o-rings for my idle mixture screws was torn in half...that must not have helped much.

One other thing I noticed is there is a hole in all four of my passages for the idle mixture screws. They appear to be above where the screw is seated. They are located on the front and would face forward when the carbs are mounted. Are these supposed to be there?

BTW, when the throttle is closed, only 1 of the 3 transition holes are visible. Think this is about right?

Yeah. Thats about right

Also discovered 1 of the o-rings for my idle mixture screws was torn in half...that must not have helped much.

No. I dont think that would help. I dont know about the 750 but I have heard others with other models say that bike will run/idle like crap without those O rings in good shape.

One other thing I noticed is there is a hole in all four of my passages for the idle mixture screws. They appear to be above where the screw is seated. They are located on the front and would face forward when the carbs are mounted. Are these supposed to be there?

Yep. They are supposed to be there. When you screw down the mixture screws up above the point will fill tht hole.

It sounds like you have done everything really thoroughly but it would bother me also that the nozzle tubes under the primary main (#62) wont come out. Can you poke them down from above ? or hook them with a dental pick ?

Thanks for the reply.
I actually took a swing by Harbor Freight last night abd got a set of dental picks to try and hook them and pull them out. I also have a really small needle nose pliers I forgot about that I'm gonna try. It's nice having a set of complete parts carbs in case you mess something up!

Any ideas about those holes I mentioned? They look like they should be there, but maybe they are supposed to be plugged?

Think I just found something... Is there supposed to be a hole through the center of the pilot jet? I'm guessing it should, but I cannot see one on mine. I was under the impression the passage from the main jet was further up, so the gas came in perpendicular to part of the jet with all the holes, not through the head of the jet (like most jets run).

That must be a very tiny hole...

apbling wrote:

Think I just found something... Is there supposed to be a hole through the center of the pilot jet? I'm guessing it should, but I cannot see one on mine. I was under the impression the passage from the main jet was further up, so the gas came in perpendicular to part of the jet with all the holes, not through the head of the jet (like most jets run).

That must be a very tiny hole...

Yes. Don't use the torch tip cleaner to unplug them. Roy

OK, I didn't... I couldn't find anything small enough to unplug my #1, so I looked at my parts carbs and stole one from there. Anyway, got it all put together and fired it up. It poped right off...but something was weird... Figured out that 1 and 2 cylinders were dead...what the heck?!?!?!

Then I realized I switched the plugs wires when inspecting my plugs... so, put the right plug wire on the right plug, and it purred like a kitten. Put on about 60 miles already and it's running like a top. Thanks a ton to everyone. I'm sure I'll be posting soon though when the next thing breaks.

BTW, why not use the torch cleaner?