head bolts

i bought my first bike motor it is a 70cc that i got on ebay' do they torque the head bolts at the factory or is that your job to do there seems to be gas in the spark plug is this good. and i am a newbie to this and i love it all your guys bikes look THE BOMB!!!!! thanks zoomcat

Welcome to the forum.

Generally, they are torqued at the factory. However, it's not a bad idea to check them especially after you've run it a few hours.

Find/borrow/buy a torque wrench. 15-20 ft. lbs. is the range you want to be in.

As for the gas in the plug...as long as it runs well, and the plug is a nice coffe/chocolate brown you are in good shape. If it seem to have a little gas on it, I wouldn't worry about it.

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Mine were torqued at the factory. Of course I screwed up the install and had to pull the head to correct it. So I can't say for sure but I think they are. If you have a torque wrench laying about it cant hurt to check them though. It should be 110 to 120 i'm told.

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Just to clarify-

110-120 in. oz. is in the same ball park as 12-15 ft. lbs.

If you don't have a torque wrench, use a 3/8" drive rachet and hold it so the rachet part is in your palm, not the handle and tighten it "pretty snug" that way.

These head bolts have been know to pull the metal out of the base if overtightened.

A little too loose will blow a head gasket (big deal) too tight will pull the threads and then you've got a mess.

Botttom line is don't worry about it unless you have a problem or the head needs to come off.

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If it ain't broke, and you mess with it long enough, it will be.

Thanks Guys For All Your Help.zoomcat

This is where you find people who like to help new bike owners.

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visit my blog for Riding in the hood,... The home brew bike journal....http://frictiondrivebicycles.blogspot.com/ The deacon's fiction (new installment daily).... http://chinesekitmotorbike.blogspot.com/

http://freekibble.com feed the homeless dogs

Zoom
Its best if you have a inch pound torque wrench to use. I torque the nuts to a max of 110 to 120 inch lbs. When I've taken the head off I use aluminum spray paint to coat the head gasket on both sides this will act like a gasket sealer. Torque the nuts in a cross pattern start at 40 in. lbs. then go to 80 in.lbs. last I use 110 or 120 in.lbs. if I've had the head off more than once I will go to the higher setting. I watch the gasket area for leaks and if I find it leaking then I make a new gasket as the old aluminum leaks pretty easy once its been messed with. I use a special high temp gasket material for the head and exhaust gaskets and it bumps up the compression a little as its a little thinner than stock. My homemade ones have yet to leak. I'll have to get the name off the material if your interested. Most industrial gasket shops will carry this stuff and there is lots of scraps that you can get. For a lot less than you would pay for in a parts store.

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Frankly, mine were quite loose......Norm has da BOMB advice.

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