mynamemf82 Posted August 1, 2015 Share Posted August 1, 2015 I aquired a 1981 Yamaha RH 550 Seca. I got it home and found that the 15 years sitting outside it didnt have spark plugs. I fianlly got the motor tore apart and now need help with the next decision.The choice is have the barrels honed to remove thr damaged parts, buy a used undamaged part. The last one is to take it and have it bored. The question is can I have the 550 barrels bored to 750 and then just buy stock Yamaha 750 ring seals and jugs?Any help would be greatly appreciated. Link to comment Share on other sites More sharing options...
slice Posted August 1, 2015 Share Posted August 1, 2015 (edited) Hi "MYNAMEMF82" I mean please make an effort - really? Anyway back to your question, I don't think you can take the barrels out to 750 but you could rebore them (550) out to max and sleeve them if they are really damaged but that might cost more than the bike, best to look out for a set of spare barrels on ebay or some such and just use the old ones as an anchor. You can't plonk a set of 750 barrels on either as they are designed for a longer stroke than the 550 you would be just throwing your money away, if you really want a 750 then might be cheaper to buy one instead of making your own. Not saying it can't be done just it will cost you more than the bike is worth to do it. Plus your bike has the 550 cdi heads and cams these won't work on the 750 barrels, least pretty sure they wont at least not without a shit load of work. Of course you might be the best mechanic there has ever been and your able to do this on a rainy weekend and the rest of us will be in awe of your skill but as you haven't said "Hello" in the New Members section we will never know (hint). It really helps if you say Hello in the new members section as folks are wary of "one hit wonders" of which we get a lot, it's just like saying Hi to a group of strangers who you met for the first time and helps folks know you here for the long haul not just cos your stuck. Just in case, Welcome to the YOC and hope you stick around cos your project sounds like fun and we would all like to see how you get on. Edited August 1, 2015 by slice Link to comment Share on other sites More sharing options...
blackhat250 Posted August 1, 2015 Share Posted August 1, 2015 Second hand engine, and save a lotta grief . 1 Link to comment Share on other sites More sharing options...
mynamemf82 Posted August 12, 2015 Author Share Posted August 12, 2015 Thank you for the help. I posted in the new members area and thank you. The other thing is that it looks like and has been brought up is that the 550 cylinders looked sleeved. Do you know if the 1981 Yamaha 550 seca has sleeved barrels as this would be the easiest as well as purchasing a new cylinder head that i have found online.Thank you, Michael. Link to comment Share on other sites More sharing options...
slice Posted August 12, 2015 Share Posted August 12, 2015 Hi Michael, you don't really need a "NEW" set of barrels, a good used set would be more than adequate for your bike and it would save you a shit load of cash, unless your really flush of course, if your present set is really badly corroded then don't even bother trying to sleeve them that will cost more than a used set as well. My best advice anyway. Link to comment Share on other sites More sharing options...
mynamemf82 Posted September 15, 2015 Author Share Posted September 15, 2015 Thank you for the advice Link to comment Share on other sites More sharing options...
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