Thread: 780 / 750 hybrid
05-30-2007, 06:11 PM #1
780 / 750 hybrid
Who out there knows if the 780 jugs could be bolted up to the 750 case???? Probably not just a straight bolt on application, but would definately be an improvement. True, I could just bore out the 750, but what would be the fun in that.
05-30-2007, 06:18 PM #2
- Join Date
- Aug 2006
it isn't that easy the 780 has some unseen differences! Z
05-30-2007, 06:44 PM #3
Direct bolt on. You will need to use the 780 gasket kit and you will have to round up a 780 exhaust manifold. Other than that it is plug and play. Also make sure you get the domes from a 780 as the 750's will not bolt to 780 cyclinder and the squish is diffrent.
05-30-2007, 06:45 PM #4
THats is what I did to my 650. But I added triples and a lot of other stuff.
05-30-2007, 07:30 PM #5
Yes it will bolt up but like mentioned, it will need the 780 ex. manifold, gaskets and heads or reshaped 750 heads for the 780 bore.
05-30-2007, 07:41 PM #6
The diamater of the bolt circle is slightly diffrent. You would also have to shave a small amount of material to get it to slide down the studs of the head. The easiest thing to do would be to get the domes with the cyclinders. That is all that is required.
Now there is more stuff that would make it better!!!!
Installing reed spacers, installing 780 or pro cdi box, and diffrent pitch impeller. Keep in mind that the 780's stock block has an extra set of runners for each cyclinder to allow more air flow into the ports of the cyclinders. And that is the only diffrentces between the blocks. I would also go though the fuel system also, and install an oil bloock off kit.
05-30-2007, 09:12 PM #7
ok, I already have bored carbs, Pro CDI, Pro Prop/extended pump, Oil block off, triple fuel, Hot Seat Intake
How much of a gain could possible be expected??????
05-30-2007, 10:21 PM #8
The pro impeller is not good to run on a stock piped 780. You would want the 92 650 dry pipe for the 12/17 Pro impeller.
The set up you posted will yield a solid few mph. I wouldn't run the Pro impeller though as it will slow you down without the 92 pipe on there. Try to find some reed cage spacers if you don't have them.
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