hyway pot and piston for 660

[shillo]

ms 660 pot and piston has gone. has anyone fitted that hyway big bore kit that i see on the bay? is it any good?

 

I have only ever replaced1 pot and piston before and that lasted a week before it went again, probably still in the hedge where i threw it!

[Stubby]

ms 660 pot and piston has gone. has anyone fitted that hyway big bore kit that i see on the bay? is it any good?

 

I have only ever replaced1 pot and piston before and that lasted a week before it went again, probably still in the hedge where i threw it!

 

I have heard that Highway are pretty good but not used one myself . No chance of salvaging the OEM pot and fitting a Metior piston ? Look on spuds " whats on your bench " thread for details of how to clean up the pot . As to a new pot and piston only lasting a week ...could be down to crappy manufacturing or could be down to you didn't fix what made it go in the first place , like an air leak or whatever ...

[Daniël Bos]

I fitted a Hyway Big Bore to mine, and it was good quality.

Casting was better finished than the oem one that came off (Kolbenschmidt), and it was an easy fit. I did a little mild porting for higher speed as the big bore kit is just that ie it doesn't make a standard 660 much faster but it does give it more grunt.

With a little porting work and exhaust modding it benefits a lot more.

 

I broke mine, through my own stupidity. I'd fitted a thinner base gasket for optimum compression but the fourth or fifth time I reassembled it after fiddling-testing-fiddling I occidentally omitted the base gasket... It ran really well, for a short while...

 

The ebay seller Tesgol is a thoroughly decent chap to deal with, (one year warranty advertised and I'd thought there was fault with the P+C). As were the manufacturers themselves who were really keen to examine the remains of my saw to determine how it went wrong, and reimbursed me the value of my scrap saw after deciding it was not a manufacturing fault.

Even though I ported it a bit, and smoothed the exhaust to a mirror finish, fluted the inlet etc these were not seen as an issue as they did not cause the failure.

 

I can honestly say that was one of the best consumer experiences I've ever had (second only to that one night in Amsterdam that my wife doesn't know about).

[spudulike]

I think Rover may have said too much:lol:

 

Stubby has it spot on, P&Cs fail for a reason, air leaks, old fuel and lean carb settings are the common culprits.

 

If you do fit new components then the cause for failure needs to be corrected or the new parts will fail again.

 

Personally I always try to salvage the cylinder as the OEM part is manufactured with tighter tolerances than the aftermarket kit and have around 95% success rate of doing this with zero failures on I guess 60+ machines.

 

I have used one Hyway kit and found build to be OK but the piston to cylinder fit was looser than OEM and that is one of the key reasons I like to fit Meteor pistons on OEM cylinders - for the premium compression!

 

Tesgol is one of the best sellers I have known on eBay and will actually resolve issues if they arise!

[shillo]

I will strip it and have a look at the cylinder.

 

The saw is knocking on 12years old.

 

The exhaust went a month ago and i put on one of those dual port exhausts, that wouldn't be a cause would it?

[spudulike]

I will strip it and have a look at the cylinder.

 

The saw is knocking on 12years old.

 

The exhaust went a month ago and i put on one of those dual port exhausts, that wouldn't be a cause would it?

 

If it was running a little lean, it may have pushed it over the edge but it is very difficult to tell.

 

I always pressure and vacuum check all seized saws to verify the integrity of the crank seals, inlet manifold and impulse line etc and then check the fuel lines, decomp and tank breather then do a tach tune to ensure the maximum revs are correct - lots of work but well worth it if you want a reliable saw.