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1979 cb750 k backfiring after getting knocked over.

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Dave1q1

1979 cb750 k backfiring after getting knocked over.

My 1979 Cb750 k got knocked over last week. I came out of my friends house to find it sideways (as if it was knocked over and picked up) and the left hand side cover of the motor (starter clutch cover) got sheered off as shown in the photo and all the oil leaked out. I fixed that, weaseled the broken off bolts out and got a new plate and screws. Now when I go to start it up, it shakes, backfires, and sometimes shoots a fireball out the exhaust. I'm newer to working on bikes so any advice I could get I'd really appreciate it. It ran absolutely fine before it got knocked down.

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Re: 1979 cb750 k backfiring after getting knocked over.

Administrator

Oh man that SUCKS!!!!

From what you describe your bike is out of time. Did the wires to the CDI, or coils get switched?
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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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fordsparky

Re: 1979 cb750 k backfiring after getting knocked over.

This post was updated on .

In reply to this post by Dave1q1

pretty sure that's not clutch cover, but a cover to the pulsar and advancer ...your timing is likely now out. Manual can be downloaded from this site with timing and gap info...good luck

see my bike at... http://honda-cb750-s.456789.n3.nabble.com/1979-CB750-Limited-DOHC-td4044851.html

Dave1q1

Re: 1979 cb750 k backfiring after getting knocked over.

In reply to this post by Dave1q1

That was my first thought was the timing could be off. I've got my buddy coming over with a timing light later and well see what we come up with.
Thanks for the input.

shinyribs

Re: 1979 cb750 k backfiring after getting knocked over.

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My condolences.

These guys are putting on the right track. I just hope all your components lived through the fall.

Dave1q1

Re: 1979 cb750 k backfiring after getting knocked over.

In reply to this post by Dave1q1

I couldn't get the bike started to time it correctly. So we adjusted the timing to see if it would change anything but it did not. I tried switching a couple of the spark plug wires around and it ran for a little while just really shitty. I also notice now that my carb 2 looks like it's dumping gas. I went through and cleaned out the carbs 2 months ago. I'm just baffled that before it got knocked over it ran fine.

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Re: 1979 cb750 k backfiring after getting knocked over.

Administrator

Do you have any enemy's?

Cheated on Carrie Underwood...
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Dave1q1

Re: 1979 cb750 k backfiring after getting knocked over.

I don't have any, but... When we were standing by the bike wondering what happend a guy ran over and said he was riding his bike down the street and a crazy homeless guy yelled at him and flipped him off. So he thought that maybe that guy messed up the bike thinking that it was his or something because our bikes look similar. Idk if that's true though because there was a car parked right next to the bike that was gone when I came back and found the bike was busted.