And then there were two.. 1976 GT250 Rebuild

[Hurco550]

hurco,
I'm hoping that piston seller will be good to you and just give you an easy exchange;I like that old blue shop air compressor, .What brand is it ?

Forgot to post this. The air compressor is "mismatched farm made" brand haha. It sat in my great grandpas basement for years, then my dads barn. Dad and I recently pulled it out and got it working again. Supposedly it was made by a local tinkerer from parts he had laying around. This winter I may re paint it and do some polishing. There is quite a bit of copper and brass on it that could be neat if polished up.

 

[grcamna5]

That's a Heavy Duty looking pump on that compressor,it reminds me of an older compressor for a truck air brake system;also good to hear what Chris had to say about the 'fit' of the new pistons

 

[Hurco550]

Went with my buddy ridesolo up to an mc salvage yard and picked up a set of expansion chambers. Needs singers welded in, and I have an extra set of pipes that I'm gonna cut the down tubes off of to weld on. Should give this little beast a little more snap, crackle and pop. I think they were for an rd250/350, which some have told me are tuned pretty close to the needs of a gt250...

 

[Hurco550]

Soda blasting for days. .

 

[Hurco550]

Started polishing. Only made it to 220 grit on the outside fins on the head, and my finger tips are already numb... long way to go.

 

[ridesolo]

Pretty nice!

 

[xb33bsa]

careful polursh too much off and itill cause a hotspot

 

[Hurco550]

careful polursh too much off and itill cause a hotspot

Judging by the work it takes to bring out a very minor scratch, I don't think I'll end up taking to much matl off, probably no more than .01" total I wouldn't think

Pretty nice!

Thanks!

 

[grcamna5]

I like that Suz. one-piece twin cyl. head hurco 8)

 

[Tune-A-Fish]

I like that Suz. one-piece twin cyl. head hurco 8)

I'd run it on the bandsaw and split it if it were possible... one side blown head gasket would be easier to fix and less chance of the warps.

 

[Hurco550]

I'd run it on the bandsaw and split it if it were possible... one side blown head gasket would be easier to fix and less chance of the warps.

Hmm that's a thought.. but its made it this long without issues... I Don't think I can bring myself to sawing the head in half lol

 

[Tune-A-Fish]

Hmm that's a thought.. but its made it this long without issues... I Don't think I can bring myself to sawing the head in half lol

Yeah you most likely won't ride the shit out of it like some kid with no appreciation for maintenance.

 

[Hurco550]

Yeah you most likely won't ride the shit out of it like some kid with no appreciation for maintenance.

Haha.... not anymore that is... now that ive put this much time, money and effort into it....

When I bought it at 18yrs old was a different story =p

 

[grcamna5]

The 79' Yamaha RD400F 'Daytona Special' also had the one-piece cylinder head and that was the last one of that generation;I think they were on to something hurco w/ the design. 8)
I have a feeling it was meant to be run real hard and matching/balanced warm-up and cooling between both cylinders.

 

[Hurco550]

The 79' Yamaha RD400F 'Daytona Special' also had the one-piece cylinder head and that was the last one of that generation;I think they were on to something hurco w/ the design. 8)
I have a feeling it was meant to be run real hard and matching/balanced warm-up and cooling between both cylinders.

It is also a common (or somewhat common) design in snowmobile heads. I know many of the Polaris liquid cooled heads were even 3 cylinder with a one piece head.

 

[xb33bsa]

it is less costly, time and money,for an oem to:design,mfg,store, keep track of and handle during assembly... with it all in one... this is the outstanding major reason for any of them being so

 

[Tune-A-Fish]

And casting has less process and remelt

 

[xb33bsa]

And casting has less process and remelt

sorry charlie ,tuna need stinkier bait, log it under mfg

 

[Tune-A-Fish]

Oh dang ;D

 

[CharlieT]

Went with my buddy ridesolo up to an mc salvage yard and picked up a set of expansion chambers. Needs singers welded in, and I have an extra set of pipes that I'm gonna cut the down tubes off of to weld on. Should give this little beast a little more snap, crackle and pop. I think they were for an rd250/350, which some have told me are tuned pretty close to the needs of a gt250...

If you are looking for some pipes for that GT250, check with Jemco. He has the specs for the factory road race pipes for that motor.