I recentlly purchased another 350x motor. I currently have one mounted in a 1991 250x frame. The one I bought is going in my 1986 250r. After I modify the chassis of course.

Anyway this motor belonged to a kid who developed an enemy somehow. The owner's enemy took the spark plug out of the bike and dropped a ball bearing into the motor. Of course the owner never knew until it was too late.

Well he offered to sell the bike to me at a reasonable price and I took him up on it. I have the top end off the bike now and have inspected the damage. The valve seats look ok but around them looks like the surface of the moon. Dips and craters galore. Now as long as the valves seal the motor will run, but with a loos of compression, right? Is there anyway to fix the dented up combustion chamber without having to purchase another head? Any thoughts or suggestioin will be greatly appreciated.

Thanks

Brad


[This message has been edited by Brad_L (edited 08-16-1999).]

 

I have a feeling it will be cheaper and more reliable to buy a new head. Take a real close look at the one you have. I have a 350X head that is cracked from the spark plug hole over to one of the exhaust valves. I don't know what caused it...

 

Brad,
I would first look at replacing the head. Any time you have a problem with it, or hear a funny noise, you will always suspect that head. Its just human nature. Besides, the dents and pits in it would cause a loss of power, all the irregularities would disrupt flow in the chamber.
If you do use it, I would suggest calling techline coatings and ordering their combustion chamber and cylinder wall coatings. I KNOW THAT THESE COATINGS WORK AND IMPROVE POWER BY ABOUT 35%. We currently are using them in 40 liter turbocharged Caterpillar engines and seeing VAST improvements.
www.techlinecoatings.com is their web-site. Although Its under re-construction right now, their phone number is on there.
Good Luck!!

 

Just a thought. Take it to your local dealer or to a machine shop and ask them if they can salvage the head. I'm sure that if the pits aren't to deep they may be able to help.

------------------
'96 Banshee, '86 250R 4TRX, 2 '83 185S

 

Hmmmm -- tough decision.

A new 350X head isn't cheap.

You can get the used one welded and re-contoured. For one in okay condition, you'd be looking at about a $200 bill for that part of the work.

Next question -- where did the rest of the bearing go? Check both exhaust seats VERY carefully, they would be very likely to show some pitting. Unless the thing finally beat a hole thru the piston.

Count on purchasing new vavles also, even if they look okay. Valves on ATV and Motorcycle engines are hardfaced over a pretty soft material -- they can't be recut (when shops do valve jobs, they're really cutting the seats, not the valves). So count on another $170 for new valves and stem seals. Plus about $60 for a valve grind.

Still, it'll be cheaper than purchasing a new head.

Another option -- a used head from a reputable salvage yard. You'd still have to buy the new valves and do the valve grind, but if you could get one for under $200, it would be the cheapest alternative.