SRX 400 OVERSIZE PISTON

[genawin]

Hello , I'm looking for available alternatives can anybody advise maybe - xt350 1.5mm o/s (87.5mm) or xt550 (92mm) has anybody got any suggestions ?
thanks Martin.

[CHRIS211083]

HI, why r u after an over sized piston??? has yours seized??? or do you want more power???

[genawin]

It has started to burn oil recently - i stripped it to find that it has old corrosion marks in the bore showing that it has stood for some time, i'm not looking for more power in fact i would prefer to keep it standard.

[Steve Lake]

you could try having the bore honed and fitting new rings, valve stem seals etc

[genawin]

Yes that's good advise i had it honed on Wednesday but the marks are still there so i have put it back together whilst the sun is still shinning ! and i source parts.

[CHRIS211083]

Well......if you dont mind waiting a couple of months i may have a really sweet srx 400 engine up for sale as im gonna fit a 600 motor???burns no oil....returns 95mpg!!!!! with only 21,000km 12,000 mile?

[Steve Lake]

just as an aside.....i sometimes run a stock 400 engine in my '6' chassis, only mod is a single 40mm dellorto on a handmade manifold....and to be honest it is a sweet motor....i think it revs better than the 600....not so much poke going up the gears, but top speed isn't far off, just takes a bit longer to get there.

[Sr.X]

like the idea of only one carb, any info on the manifold construction?

[jester_parks]

XT350 has 19mm piston-pin, XT550 has 20mm!
Sizes of the pistons I can give you  as I`ve got the two pistons at home (and some more) for my own big-bore project!

[mini-thumper]

like the idea of only one carb, any info on the manifold construction?

Have just posted an advert in 'For Sale' for a single carb. XT/SRX manifold.

Boyd

[genawin]

XT350 has 19mm piston-pin, XT550 has 20mm!
Sizes of the pistons I can give you  as I`ve got the two pistons at home (and some more) for my own big-bore project!

Hello Jester, have you got a piston between 87 and 92mm, i have just bought a xt550 piston from the U.S. (unfortunately damaged) and it has a 22mm gudgeon pin ?
could anyone confirm the srx400 pin size ?
thanks Martin.

[jester_parks]

....have you got a piston between 87 and 92mm.....


certainly I have! Will check at home and let you know!

[genawin]

....have you got a piston between 87 and 92mm.....


certainly I have! Will check at home and let you know!

I have pulled it apart again and noticed how thin the liner is plus a second look at the bore has pushed me in the direction of new set of rings and keep my fingers crossed as the marks in the bore are minor , i might have a 2nd hone . so if you have some srx400 , xt/sr 500 std or 1st o/s rings please let me know.

[Jez F]

Have you considered Triumph (new) Bonneville pistons, theyre 90mm with a 20mm gudgeon pin. I haven't checked the crown height  yet. I bought a pair while I was considering overboring a GN400 and the whole lot is still in a box under the bench.
Jez

[Ian]

Photo included of Standard SRX-4 piston/barrel
Ian