spark plug problem

1854 Views 7 Replies 2 Participants Last post by CB750F, Apr 9, 2007

mrukus

Discussion Starter · Mar 29, 2007

yeah, i was thinking about turning the engine over today, but first, i wanted to lube up the cylinders a bit, so i started to take teh spark plugs out and squirt oil into teh clinder so it could sit over night and then turn the engine over by spining the back wheel. well, i got spark plugs 3 adn 4 out. then when i tried two, it snapped off, no i am stuck with the nut part of the spark plug stuck in my socket, and the bottom half of teh spark plug stuck in teh head. Now, i am goign to try and wedge a screw driver into whats left and then try to screw it out, any ideas? if worse comes to worse, i am just going to geta new head, but i am also goign to try and drill it out if i can't get it out. Thank you very much for your advice in advance

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CB750F

· #2 · Mar 29, 2007

Might be able to get an Easy out in it. Don't break the Easy out off in there or you're really screwed. They are like super hard steel. Soak it real good in penetrating oil first. Go to the Chevy garage and ask for their penetrating oil in a can, I forget the name but it's good stuff.

Something tells me the heads going to be coming off. If ya drill it you'll probably have to put a Heli-coil in it unless you're real careful.

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mrukus

Discussion Starter · #3 · Mar 30, 2007

might it be easier ot just get a new head? or would drilling it out just be the cheapest method, i just lost 120$ that could have gone to the bike to a freaking ticket today, so the bike fund has become even more strapped. And thanks for teh advice on the calipers, i have teh pistons out of teh cylinders, and now i am rebuilding the carbs, everything was going fine till this happened. about how muc would a new head go for, or a used one. Is there also anyway i find out the def. model of the bike. i mean, its a cb750, but what about all the ks and the a's. Thank you very much btw, its nice to talk to another motorcycle enthusiast, everybody thinks i am crazy!!!!

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CB750F

· #4 · Mar 31, 2007

You would pay serious money for a new head so your best bet would be a used one. Try and find one with low miles if ya can. I'm guessin' somewhere aroud $100. Take your head off and take it to a machine shop that does heads. They might be able to save it. You're gonna have to pull the engine out of the frame to get the head off if it's a 78 and down bike like mine. The newer DOHC from 79 and up I'm not so sure. if yours is the DOHC one do not get the valve shims mixed up. They have to go back on the valve top you took them off of. The DOHC ones are a pain in the ass to adjust valves and you'll need some specialized measuring tools such as a micrometer of ya get stuff all mixed up. You can check the valve lash with feeler gauges however. The SOHC ones are super simple.

The K suffix ( such as CB750K ) is the standard bike. The A suffix is a CB750A which means it has the automatic transmission. The F suffix like mine is a Super Sport. Kind of the pre-crotch rocket bike of today. This only applies to the 69-78 CB 750's. Later (79 and up)they didn't have the automatic bike and it was just the K which is the standard bike or the F which is the sport type one.

You're welcome anytime.

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mrukus

Discussion Starter · #5 · Apr 2, 2007

sadly, i have teh DOHC. i will ust be sre not to get them mixed up. idk if i have the k or teh f though, is there any special things to look for. i guess i could just check the model number, its a 80 btw

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CB750F

· #6 · Apr 2, 2007 (Edited)

It will say on the model number if it is a K or an F. Up on the steering neck the model number and VIN should go CB750 then the model designation then the rest of the VIN number. Usually the F's have a kind of spoiler lookin' thing on the back of the seat, a flat seat if yours has the stock one and painted fenders. The K's have chrome fenders and a stepped seat and semi pulled back bars.

http://www.afegraphics.com/80cb750fblack/80cb750f-black-bike-iso-ad-shot2.jpg Picture of an 1980 CB750F

http://www.hondabikes.net/forum/archive/1980-cb750k-sold-sold-sold-4745.htm CB750K

Oh yeah there is also a CB750C (Custom) which looks a lot like the K but more fancy.

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mrukus

Discussion Starter · #7 · Apr 9, 2007

problem solved. My girlfriends dad used to work at a machine shop. we got to talking and he is goign to heli coil it for me. we tried the easy out and it didn't work, and then i tried to get off the last sparkplug and i snapped that one off too. but he is ogign to machine it all and make it look nice. tahnks for rthe advice.

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CB750F

· #8 · Apr 9, 2007

Anytime dude! It's pretty nice to have someone around that can machine stuff for ya. Don't make him mad............ever.

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