Carb Advice Needed(I Think)

[husabob]

All, I have a 1979 Special, and left cylinder will not fire until about 1/4 throttle. Then it seems to run fine and pull the same as the right cylinder. I have cleaned the carbs several times, pulling the jets, etc. I have not pulled the carb tops to look at the diaphragms. Should I? I also just picked up at a flea market an unused set of PWK's, complete with cables, pod filters, extra jets, and manifolds. The box also contained a spare set of OEM carbs with mounts, 2 complete coils, and a supposedly good CDI box. I think I have enough parts to get this running correctly. Where should I start(no pun intended)? All advice is appreciated. Thanks, Bob B

 

[5twins]

Are the carbs in sync?

 

[husabob]

The butterflys are synched. What I have not been able to determine is whether or not the slides are moving at the same time. I'll hafta get someone to twist the throttle while it's running so I can watch the slides. It was also suggested to me that a bad CDI unit could cause this, and I just got a hopefully good spare.

 

[hmusket]

Unless your '79 has been modified it does not use an electronic control box, what you're calling the CDI. It uses points, so check out your timing and advance. Go to the tech section on the forum for more info.

 

[XSLeo]

Yep, 79 has points. The symptoms you describe sound like a plugged idle circuit in the left carbs. To clean and tune your carbs you need to read www.amckayltd.com/carbguide.pdf
Leo

 

[husabob]

I have downloaded the manual. Thanks. Teardown will commence soon, and I might give the carbs to a buddy who has an ultrasonic cleaner at work. Of course I'll remove all rubber and plastic bits beforehand. I also confirmed the manufacture date as 7/79 on the steering head, and the numbers match. If I can get the stock carbs to work as they should, then the PWK's and bits will be posted in the For Sale forum.