Do I need a new head??

I always hate starting a new thread, but I'm really stumped and can't find anything to directly answer my questions.

I recently had to tear down my motor because of a chain reaction that bent my rod, scarred my cylinder, shattered my piston, and bent all 5 valves. This is the second time that its happened so I figured I should fix it right this time (sorta). I picked up a crank and valve assembly used for 45 bucks from a guy with an 04 that used the parts for one season. It all looked good and the price was unbeatable so I went for it. Then I got a piston and cylinder combo off eBay for 80 bucks.

Now its all together and it runs pretty strong. It has about an hour of time on it. I changed the oil, filter, and coolant to get any left over metal shavings out before they could cause any damage.

With all of this being said, after it warms up I can't let it idle because it'll die suddenly. I don't think it can be fuel, air, or spark related because it runs strong while being ridden. When the valves were going in, I had to push them up and down to get them moving smoothly. Could this be the problem? possible an exhaust valve catching something on the head and staying open to long making me lose compression? or could it be Just valve lash issues? I checked them when i put them it, but maybe something?? I really can't afford to rebuild this thing again. Suggestions?

Did you replace the valve guides?

Usually....... valve guides are reamed to fit the valve stems. Sounds like some measuring on the stems is missing maybe.....?????? Or the tips of the valvestems had flaired slightly and you forced them thru and scored the guides. QU. Once they were in, were they still stiff? Time for a leakdown test. Listen for where the air is coming out.

Will it die if the idle is set higher? If it does then I'd look at the carb and replace the pilot Sounds like it's lean at idle

I did not replace the valve guides. once I got them in, i had to push the valves down several times to get them moving smoothly. So scoring the guides sounds possible.

I haven't tried raising the idle yet because it does run really smooth, but pilot jet could easily be clogged.

I'll start checking all of this out today. Thanks

Well...I figured it out. When i was cleaning the carb, the fuel screw got screwed in all the way. So now its all good. But When I was putting the inner clutch cover on, i broke the water pump impeller shaft. Thats the third time I've done that in the past year!

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