marshg246
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- Jul 12, 2015
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It should probably has the 3rd bearing iteration - first one called SuperBlend, but not the final SuperBlend if dealer fixed. They quit calling them Combat, reduced the compression and started calling them high-performance. The RH3 head was skimmed .040" where the RH6 head was skimmed .020". AFAIK, the RH6 750s did not have the 2S cam.I’ll add a little something to the lore and also have a question. I’ve got a 750 roadster, serial #211407, build date August 1972. So, just post Combat. The original black tank, not currently in use has the “D” stripe. The instrument cases are polished alloy. The barrels are painted black which looks to be original. Front disc there from new. 32mm original Amals ( little slide wear, I rebuilt the internals and they run fine) 19,000 miles and I’m the 3rd owner. I’ve had it 10 years. The second owner had it sitting around in a collection for 15 years or so and rarely, if ever, road it. From the data provided by Greg Marsh it appears that it would have been built just ahead of getting the factory installed “Superblend” bearings. And it would have been fitted with either the RH5 or RH6 head with the 32mm intake ports. My question: The head has almost no material below the bottom fin, and the gap between the bottom head fin and the top barrel fin is noticeably less than the other fin spacings. Would that be an indication that it is the higher compression RH6 head? (I’ve never had the head steady off to see if it’s marked)
Of course, the head could be skimmed or changed after leaving the factory.
Part of SR N3/23
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