250SX Cams, chains,sprockets and head??

[Dirtcrasher]

I need a cam to match my High compression piston. Someone mentioned Webcams?? I did a search and all I can find is web cameras - as in look at other people etc etc.

Any ideas where to find a cam for the 250SX??

I have found heavy valve springs for the SX.


Also when is it time to replace timing chain and sprockets??

All the manual says about the self adjusting SX is that the adjuster should pop out about 1/4" when loosened or it's time to replace them.

Although I have inspected them and they are not like "drive chain and sprocket" wear as I see no visible hooking etc. but I just wondered some of your thoughts.

Of course the safe thing is to replace both sprockets and the chain and the long guide.

And other than obvious bent or damaged valves I'm not sure what the hell I should do with the head as it looks and ran just fine - but I really don't want to mess around with this thing either. Stock SX valves should not be ground so do you just leave them be or what?? Can't even lap them I guess but maybe just check the guides and seals??

Someone here also sent there head out and got a good price but I'm not sure who that was or if anyone knows of another place??

Thanks for any help!

[kdagenais]

I can't help you on the cam but the timing chain I would suggest pulling the clutch cover off and remove the tensioner from the timing chain and see how much it takes to tighten it up. Personally after my last experiance I would probably just change it since a new chain is around $60.00 and what could happen if it slips can cause a lot of damage (bent valves, Hole in piston etc.)
Now as far as grinding the valves my machine shop guy ground mine on my 250SX and I've had no problems with them yet. I know the book says not to but my trike has several hours on it since the last rebuild with no issues.
Good Luck on your project!

[eh_tee_see]

http://www.webcamshafts.com/ there you go buddy, i wanta wanna those cams

[Dirtcrasher]

I still wonder though if you can just replace the timing chain and not the sprockets themselves? If there is no hooking in the sprockets I can only imagine that the chain and pins themselves are what created the excess play.

But when you use your "drive chain and sprocket" logic you feel you should do them all at the same time - which isn't cheap when buying OEM Honda.

Yes, I plan on having a complete ball with this motor which will compliment all the other 250SX mods on there.

[kdagenais]

When I did mine I replaced the slides and chain only so far no issues. I know this is a big no no with a drive chain and I am sure it applies here but sometimes budget is everything. But when you consider a timing chain is under very little stress and is constinetly lubricated I can't image the sprockets wearing like a drive chain.
The only reason I replaced the slides in mine cause the plastic was falling apart so I didn't want to take a chance with that. As long as the chain is tight when it goes back together I sure you shouldn't have any issues.
I will never do another top end rebuild without replacing the chain after my last experiance. I bent 3 valves cause the chain kept slipping out of time and I couldn't figure out why. The only way I found out was to remove the clutch cover and seen the chain was loose as a goose with the tensioner in the tightest position.
Anyways that is my 2 cents!

[samster143]

Check out Ritter Cycle Racing. He advertizes in the back of Dirt Wheels. He did a valve job for me for $50. Kinda slow, however. Real nice work. I do not have his number, sorry, but check out Dirtwheels for his ##. I would change the sprockets with the chain, Just for good measure! Good luck!

[Mobular]

Try megacycle cams:
http://www.megacyclecams.com/catalog/catalog.pdf