Join Date: May 2002
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Re: Zuki Update ... and Questions
I would suspect several things, possibly in combination, in the following order:
Initial (cold) Choke plate setting, and cold idle setting. (it should be closer
to 2000 or a bit more with the choke set) Get your air cleaner off and "set"
the choke. (1 full push to the floor and let it up) The choke should be almost
completly closed and at the prescribed setting. At an outside air temp of 77
no more than .020 (inch) open (.004 min). and at 104 air temp, a maximum of .11 (inch).
This is measured at top edge of the plate to the throttle bore.
As mentioned, check the vacuum pot to the choke.
There are 2 idle speed adjustments. The hot idle is fully exposed and visible on the
linkage (in back of the carb facing the firewall). The hot idle mixture is controlled
by a linkage cam and the cam has a mark where the follower should line up. I haven't
adjusted this one so I'm not sure how its done. (Anyone else?)
There is a fix for a known carb issue the adds a piece of tuping to the vent tube at the top
of the carb near the choke plate. Some carbs leak fuel through this tube, and an extension to
the tube fix's this problem. It is usually more of an issue climbing hills, but can in some cases
happen on the flats. I suspect that when this happens, on the flats, it is caused by the
float level being set too high. This may be the case for you.
The hot air inlet to the air cleaner may also be involved, so be sure its working and the flapper
valve operates properly. Hot air when the engine is cold helps it run smoother.
Black smoke will be a too rich condition, Blue smoke will be oil being burned. Ff you have soot,
its almost certainly too rich, and unless the carb is completely junk, should be able to be adjusted out.
Most carbs that are un-repairable have worn out throttle plates that leak vacuum at the throttle plate
shaft, have gummy deposits in the tiny feeder passages inside, or a chunk of something wedged
where ordinary cleaning cannot remove it.
Most carb problems are adjustments out of whack, dirt in the float bowl, or bad gas/water in the fuel,
or ECM and ECM controlled junk dying, dead.
I doubt your ECM stuff is bad, or it would not warm up past the problem.