dammit. I was REALLY hoping to not have to pull my heads. guess I'll rejet it and pull the heads. does the motor have to come out to pull the heads?

 

also, how would I know if a valve is burnt?

 

The head can be removed with the motor in the frame. Some clues to valve or seat damage are carbon build up, discoloration, melted or cracked metal. You can do a leak down (compression) test before pulling it apart. If there is damage you will have lower compression or a rapid pressure loss compared to the other cylanders.
Here are a couple of examples of head/valve damage.

[IMG]local://upfiles/23095/DC59AF9BBE63444580C9D3CBCD7DA70B.jpg[/IMG]

[IMG]local://upfiles/23095/B7FDE7AABD364822B1D7FEBAC457F7B5.jpg[/IMG]

 

give me a few minutes and I'll post up what my cylinders and heads look like so you can give me an idea or two. I opened the exhaust valves and noticed what looks like a white carbon inside on the valves. not like a HUGE deposit of it, but theres a fair bit.

 

Yup. Looks like you are running lean. Exhaust valves look like they have been hot. Clean up your heads and valve seats, as well as the top of your pistons. Rejet the carbs so you are getting adequatefueling at high rpm. New plugs wouldnt hurt either. Hopefully you caught this before there is too much damage.

 

Alright cool. I've got a stock exhaust system here, can I just swap to that for awhile and enjoy quiet without worrying much?

I'm glad there doesnt appear to be much damage. Today I'll pull the valves out and clean em up inside just to be safe and make sure everything is good.

 

Stock carburation and exhaust wont cause any more harm. Make sure you clean both the valves and seats. With those deposits on the pistons and top of the combustion chamber there must have been chunks coming loose. Were you getting carbon deposits at the tail end of the exhaust or black smoke when you rev it?
In any case good luck getting it cleaned up and reassembled. Keep us posted.

 

at times yeah I was getting black smoke. I cant get the valves out apparently, is there any chemical that will eat the carbon deposits of loosen them without damaging anything else?

 

There is a product called OCD-4 that is used to remove carbon deposits and be safe on the base metals. Google it. Im not sure where you would buy it or something like in your area.

 

I couldnt find anything on that. but I found a dental pick that works to scrape a lot of the carbon out of the exhaust port and from the valves. HOLY CRAP. it makes sense why it wasnt running well now, there was so much baked on carbon on the valves facing the pistons, and a lot in the exhaust ports too, like a small handful that I've gotten out so far. unbelievable. once I get everything back together it should run a LOT better I hope.