2 part carb question

Inside the bowl of my carbs there is a polyester cap inserted in the hole after the pilot jet goes in. Do these caps have to be there?

And also, just finished cleaning and sync'ing the carbs. Runs great at idle and accelerates great. When I am cruising with rpm over 3500 the bike runs fine with good throttle response but when riding in low rpm range (anything below 3000) the engine is very logy and bogs out when I hit the gas. Any ideas?

The bike is a 1982 LTD-4.

The plugs over the pilot jets indicate that the pilot jet gets its fuel from a cross-passage to the main jet. If the plug isn't in place, the pilot jet will be swamped with gas from the bowl and the bike won't idle.

Thanks. If the o-rings for these caps are in bad shape allowing gas to get by, would this cause my problem at low rpm.

Also, I have read that I need to adjust the air screws 1-1.5 turns from seated until the motor speeds up. I have tried each carb from 0.5 to 3 turns and did not notice any difference. I now have it set at 1.5. How will this effect the idle and running of the engine?

Are these Mikuni BS34s? If the caps are metal and have orings, they won't stay in place, once they have been installed and then removed. Air screws have limited ability to affect the air/fuel mixture at idle. That is why many of the late 70s/early 80s carbs came with pilot mixture screws which affect tuning of the idle circuit a lot more.

I'm not sure the type of carb. That always confused me. I have attached a picture from kawasaki.com that looks like the ones I have.

Tha caps are plastic ones (actually they are about 1/2 inch long and have a head on tham like a nail). I just checked the float height using clear tubing and each carb is different by as much as 1/4 inch. When I assembled the carbs I did a dry adjustment, guess that's not very accurate. I will try adjusting again and see if that helps.

Post edited by: 782david, at: 2006/05/31 15:40

Just adjusted the floats. While the bowls were off I cheched the plastis caps over the piolet jets. Two of them just pulled out very easily (almost fell out). I need to replace the o-rings I guess. I called my local Kawasaki shop and they don't have any in stock and will be a few days to order (they are $6.95 each). Is there any other way to plug the holes?

Just to be sure, what is the number on the drawing associated with the plastic caps you are referring to?

The cap is #13 and the o-ring is #14. I picked up some o-rings at a hydraulic supply shop and they fit perfect. Hopefully gas won't break them down (the guy said it shouldn't). I just finished adjusting the floats and test ride, what a difference. Idles perfect and runs great at all RPM ranges.

Are the carbs pictured the type you mentioned?
Thanks

I had the same thing.. orings on the plugs were shot.. I have the same carbs.. replaced the orings and other misc things and runs greate..

I have to replace those o-rings on my bike as well, but don't want to pay $8 for them from the dealer. Do you recall the dimensions of the ones you got? It would save me a lot of time if I don't have to try and track that down. Thanks.

Sorry, but I don't know. I brought the caps with me to the shop and the guy picked out some that fit. They had metric and standard sizes and I 'm not even sure which ones I got. He gave me 3 sets of 4 in different sizes. Didn't even charge me for them as it would cost more for the paperwork then for the o-rings. When I got home I tried each till I found one that fit. Good luck.