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Long time to start. Dying, won't idle

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JMasters0011

Long time to start. Dying, won't idle

Hey everyone, Having a problem with my cb750k. Takes a long time to start. Then once it does, i have to keep reving the motor to keep it going. Once I let off the throttle it dies. If I keep giving it gas and pop it into first gear the biek dies once i let out the clutch...I've gotten it going once or twice out of first gear then again once i put in the clutch to turn and the rpms go down it dies. I'm thinking it the carbs not all firing and not tuned. I bought it a few months ago and didnt know the last time it was tuned.

Any answers for me?? Thanks
Joe

TOOLS1

Re: Long time to start. Dying, won't idle

Administrator

Your pilot jets are plugged up. You will need to clean/rebuild the carbs.
TOOLS

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1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
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Lucky 1

Re: Long time to start. Dying, won't idle

In reply to this post by JMasters0011

You did not tell us what year it is.

It needs a complete work up.
Check all fluids.

Battery charge.... or new battery.
Carb idle jets could be clogged.
If it has points ignition (original ) they could need adjustment or replacement.
The valves could need adjustment .
The cam chain could have too much slack in it. (But it would still start.)

Check carbs LAST after all other checks are completed.

On a Roadstar Adventure.

Lucky 1

Re: Long time to start. Dying, won't idle

In reply to this post by TOOLS1

I certainly would check that out. I agree.

On a Roadstar Adventure.

JMasters0011

Re: Long time to start. Dying, won't idle

In reply to this post by Lucky 1

Sorry, its a '79 cb750k, it has a new battery.

SlayerFan

Re: Long time to start. Dying, won't idle

I have an '82 CB750C with the same problem... I've installed K&N individual filters, cut the stock exhaust off right where the headers meet the mufflers (to make shorty Drag pipes) and installed a Stage 3 Jet Kit. It wouldn't idle for me before doing this stuff, so I did a cursory cleaning because things were pretty varnishy smelling...
I guess I'll pull the carbs back off and give everything another cleaning.
Balls :(

Once I get it idling properly, I can work on the backfiring problem.

Dr. Rockso The Rock 'n' Roll Clown

How I've waited for you to come;
I've been here all alone.
Now that you've arrived,
Please stay a while...
I promise I won't keep you long,
I'll keep you forever..........

Lucky 1

Re: Long time to start. Dying, won't idle

It will need to be rejetted Dr. Rockso.

On a Roadstar Adventure.

SlayerFan

Re: Long time to start. Dying, won't idle

I took your advice to the original poster, Lucky1, and recleaned my pilot jets... I had done a decent cleaning prior to this but didn't have a screw driver which would fit to reach the pilots, so I just sprayed through them. I did a much better cleaning last night and got her fired up (it still took some effort) but finally once she was warmed up, she would Idle. Now I can work on that pesky backfiring at idle issue! I'm gonna work with the mixture screws first, though they're already 3 1/2 turns out per the Dynojet Stage 3 instructions. I'll see what I can come up with. Thanks for your input, Lucky1 Rockso

How I've waited for you to come;
I've been here all alone.
Now that you've arrived,
Please stay a while...
I promise I won't keep you long,
I'll keep you forever..........