1000 heads on a 1200 motor

Technical information and Q&A applicable to all years and models of Goldwings
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Posts: 409
Joined: Thu Apr 29, 2010 9:52 am
Location: Grand Forks, ND
Motorcycle: 1977 gl1000

1000 heads on a 1200 motor

Post by ekvh »

I have seen a few who claim to have done this, yet the specs show that the 1200 had a 4.6mm longer stroke than the 1000 and 1100. The ones I have read about claim a lot more low end tourque from the longer stroke, but improved top end from the cams especially if from earlier 75-77 cams. Carb venturi is the same on the 1000 and 1200 but intake valve is larger (2mm) and open longer on 75-77's. NGWclub has a few who have it, but I cannot seem to access their site. It would be a nice marriage, the 1000 noted for higher revs, and the 1200 for higher torque. Anyone who can verify that this can be done without interference from the valves and the pistons?

Old Fogey
Posts: 884
Joined: Fri Oct 30, 2009 2:09 am
Location: Glasgow Scotland
Motorcycle: 1976 GL1000
1979 GL1000

Re: 1000 heads on a 1200 motor

Post by Old Fogey »

This link should work;

As in another reply, several folk have done this but if you have doubts it's easy enough to verify the valve/piston clearances. Put some Plasticine onto the tops of the pistons in the valve cutaways, replace the heads with old gaskets and turn the engine over gently. Remove the heads and measure the squashed Plasticine. You want a minimum thickness (clearance) of around 0.060" or 1.5mm. Use a Dremel type tool on the cutaways if necessary to give you that.
Oh yeah. Smear the valves with oil before you replace the heads to stop the Plasticine sticking to them.
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

( Seriously, you haven't read all 115 pages of my http://www.wingovations.com website ?? :shock: )
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