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Discussion Starter #1
Hello again everyone,


So about two weeks ago I rebuilt my carbs from the ground up. Cleaned everything, replaced all the worn out parts and put it back on my 1980 cx500c. It ran like a dream! However, 2 days ago I was doing some heavy accelerating and after shifting to 2nd gear (from about 8000 rpm) my bike started to bog down. I tried downshifting and the rpms went up but I could still feel it dying. The red indicator light also turned on during this time. When I released the throttle and pulled in the clutch the bike immediately died. I pulled the bike to the side, put it into neutral, and it started right back up no problems at all. Finished driving (no hard acceleration) and it worked fine. Next day I wanted to see if I could get it to happen again so I accelerated hard from rest and the same thing happened. No matter if I downshifted, upshifted, gave it more or less throttle the bike slowly died as my speed decreased, all with the red light on. From then on I have had very little acceleration and it seems like the bike is pulling a train. From any speed and rpm it just bogs out and is very slow to respond. My first thought was that it's not getting enough fuel. So I brought it home, made the fuel line a little more "direct" and made the carbs a bit richer. Took it out and that didn't solve the problem.
I'm going to take a look at the valve clearance tomorrow just to make sure it hasn't changed, but I was wondering if anyone had come across this issue before at all? I'm assuming it has something to do with the carbs, but I'm surprised that the jets would be blocked after I just cleaned them all out.


If you have any ideas or at least a starting point to look at I would so very thankful!
 

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Sounds like a float issue. Could a chunk of debris been left in one of the carbs post-rebuild, and gotten into one of your carbs, and is causing one of the bowls to go "dry"? (Only thing I am going on is a past car issue, and I had very slow acceleration on my 79, and that's what my carb guy just told me...)
 

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first thing is first lets figure out the oil light

is your oil level ok

dump your oil make sure it is not sparkly and shimmering

if the oil looks good continue

next change the filter incase it is blocked or defective look at the filter under a bright light is there any sparkly metal bits on it?

if ok then

fill with fresh oil start the motor and see if the light is going out
 

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Discussion Starter #4
Armorfiend: That may very well be the issue. I'll take them out first chance I get and see if the floats are working good. One thing I noticed when I rebuilt the carbs is that the floats sat higher up than before, that is the tiny spring inside the new float needle was stiffer than before. I checked the spec and they were a fair amount off. Would this cause issues like what I'm experiencing? I'm also thinking it might be something to do with the high speed jets. I'll check when I have the carbs out I guess.

Murray: Thanks for the advice! Turns out my oil level was a bit low. I topped it up for now and will check to see if there is metal shavings in the oil ASAP.
 

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Discussion Starter #5
Update:
After checking it out yesterday I noticed that rather than no acceleration at all, under 4-5 thousand rpms it's got some acceleration, but as soon as it hits that mark it just doesn't want to go any faster no matter how much I twist the throttle. I heard that a similar problem can arise if using the old CDI unit, but as I am running the ignitech replacement module (and have been for a year now) without any problems, I don't think this would be the issue. Has anyone heard of the module failing before? Tomorrow I'll take the carbs out and see if I can spot the problem. Hopefully it's an easy fix!
 

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Discussion Starter #6
Update:
So I took the carbs apart again, and everything is nice and clean still. Floats are all working good. I was reading up some more and it sounds like the issue may be a bad coil. Gonna get some new plugs, boots and coils and see if that solves the problem.
 
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