Big Bore Big Block Kit i just found on a new source!

They are 40 year old machines. Be smooth and it won't be a problem. Full race cam etc different story.
That's the nice thing about the extra displacement. You don't have to lean hard on it to get a good performance.
 
I welded my crank when I rephased, but that was more of while I'm here type thing. I had done some extra for a welder where I worked so he TIG welded it for me on break one day.
 
I also ordered a Big Bore kit for my 81 that will be my Tracker setup. Can I just install the kit without any mods? Reading here it looks like I can. I assume the carbs will need re-jetting. What else do I need to order?
Thanks.
Bill
 
I also ordered a Big Bore kit for my 81 that will be my Tracker setup. Can I just install the kit without any mods? Reading here it looks like I can. I assume the carbs will need re-jetting. What else do I need to order?
Thanks.
Bill
You might also need a welded and balanced 277 rephased crank with Carrillo rods, new cam chain and guides, 277 rephased cam, hardened rockers/adjusters, valve spring kit with titanium keepers, bronze guides, moderate head porting, 34-6mm round slide Mikuni carbs and matching aluminium intakes, a complete performance exhaust system, and a new 277 ignition system, a complete Barnett clutch set up and at least $1.000 in misc. Just Kidding:jk:
 
Last edited:
I’d imagine at a minimum there are some “your already in there, might as well” things to do.

cam guide, chain, seals - if your clutch plates are a old, new friction plates and possibly some stiffer springs are in order. I’ve owned 3 stockish XSs and never had an issue with clutch slippage but it’s something that is quite often reported even more so with a bit of extra oomph...

check valves, guides, springs etc... clean, lap - valve seals...

anything easy to get to while it’s open should be checked/cleaned/replaced...

an exhaust that can breath wouldn’t hurt either.
 
Last edited:
The 750 kit gives you a 15% increase in displacement.
No other mods, and running at cruise rpms, about a 15% increase in torque.

The cube root of that is the demand for speed, which is close to a 34 --> 32 rear sprocket or a 17 --> 18 front sprocket change, for equivalent engine loading at hwy speed...
 
Knock on the door at 9:00 this morning. It was Santa Claus dressed as a UPS man.:yikes: BBK arrived in perfect cond.:thumbsup:

Santa was at my house 30 minutes ago too. He’s good! I like that they provide 2 sets of rings with this kit. It’s not advertised like that, and I’m not gonna complain!!!!’

Busy guy this week...stopped by here about 30 minutes ago
 
I am also getting rid of those glass fuses on my 81.
From being on this forum for many years now, I know that many folks do switch over to modern fuses - there are some good reasons to do so. I didn't go that route, though, when my OEM fuse block needed some love. The problem wasn't with the glass cartridge fuses, but with the brass clips that crack, break or just lose tension on the cartridge ends of the fuses. I bought a similar fuse block from Radio Shack (now you know about how long ago this was), swapped the clips into the OEM fuse block, and soldered the leads onto the new clips. Ten thousand plus miles later, never a fuse problem. I have a stash of cartridge fuses - yeah, they're old school, but they've done their job for many decades. (The pic isn't the one on my bike, but mine looks just like it.)
 

Attachments

  • RadioShack fuse box fix.jpg
    RadioShack fuse box fix.jpg
    256 KB · Views: 103
I did not get a extra set of rings. Come on man.
I just checked and the BBKs that came today also came with one set of rings.

Will recommend the early seats he sells also.
Front; from yamahaxs650, rear is used seat via member here prolly the NLA seat from mikesXS. (they are the same) and quite nice. Pan unlike the beat with a hammer units from Vietnam, is near identical to the stock pan. Only a rivet counter would find any difference.
20210212_122019.jpg
20210212_121959.jpg
 
One more thing. 80-84 Special owners - check out the cafe/sports seat #68-6906
under chassis/brakes - seats, seat parts section on yamahaxs650.com This seat radically
changes the look of a special to a cafe/sports bike so that once you ditch the high bars,
the grab rail and the stock tail light you have a whole different bike. The maker of these
seats ( all models ) will be no more as the maker now makes stock seats for Honda OEM
and has not accepted our 1600 seat order.
Remember - If you don't have the body work then you have nothing !
 
Back
Top