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1974 CB750 starter motor issue

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JonathanHValencia

1974 CB750 starter motor issue

This post was updated on .

Can someone tell me what this is?
I installed a new starter motor and a new kill switch. I tested it just now for the first time just to ensure the motor was good and I got this noise. No carbs currently installed, and my timing is way off. I only did this to test the motor would receive power and I’d hear the classic noise.

Help please
Here is a video

https://m.youtube.com/watch?v=ktHig-nQQRI

TOOLS1

Re: 1974 CB750 starter motor issue

Administrator

Do NOT pay any attention to that idiot!!!!!!! You do NOT crank the engine without the cam chain tenshioner on it!!!!!!!!!!!!!!! As for installing the cam chain tenshioner, you loosen the lock nut, then loosen the lock bolt, push the tenshioner rod back in, snug down the lock bolt, and install the tenshioner. The you loosen the lock bolt to release the rod. Turn the engine with the kick starter, or a wrench on the crank (going in the proper direction for whichever side you have the wrench on) a few turns. This takes all the slack out of the chain. Then snug down the locking bolt, and the locking nut. You are done.
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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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JonathanHValencia

Re: 1974 CB750 starter motor issue

Tools I posted the wrong link. Sorry.

https://m.youtube.com/watch?v=ktHig-nQQRI

TOOLS1

Re: 1974 CB750 starter motor issue

Administrator

It sounds like something is stopping your engine from turning over. Did something get sucked into the head through one of the intakes? Have you tried the kickstarter? Why did you change the starter motor? Those hardly ever go bad. Oh, also did you crank the engine with the cam chain tenshioner off it?
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JonathanHValencia

Re: 1974 CB750 starter motor issue

I took the carbs off. Nothing preventing. Only thing that’s bad is my timing I haven’t fixed and the carbs I have off to rebuild.

TOOLS1

Re: 1974 CB750 starter motor issue

Administrator

Timing has nothing to do with what you have going on there. Answers to those questions I asked would go a long way in helping you.
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JonathanHValencia

Re: 1974 CB750 starter motor issue

I only tapped the ignition button to elicit a response from the starter motor, not with the intention of turning on the bike. Literally just tapped it for 1/4 of a second. I covered the intake, nothing should be in the head that doesn’t belong. Also, never cranked it with the cam chain tensioner off.

TOOLS1

Re: 1974 CB750 starter motor issue

Administrator

OK, Did you try to use the kick starter to see if the engine would rotate? Also, does your battery have a good charge?
I just watched the video again, are those rubber gloves sealing the intakes? If so, try taking them off and cranking it (it does not hurt to crank the engine without the carbs). The engine is an air pump. When it is turning, it must have air going in and out, even if it is not actually running.
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