The choke isn't on.
The decel enricher diaphram is good
the squirter pump is working great.

 

Next time he does somthing like that, ask him this simple question, then answer it for him!

myurl

 

Just tell him that if it starts tapping louder than normal to kill it RIGHT NOW. The rockers get noisyer when they are dry, mostly at low rpms theyl tap tap tap realy hard.

 

120psi is good compression, and the carb is clean. All of these engines will have shavings in them to a certain degree everytime that you change the oil. Not to the extent of yours though, thats what mine was like when the engine let go. It wont appear as bad in Hondas because they use a different type of filter element that doesnt let them show up as bad, but the Yamaha's works just as well, its a type of material that is used in aircraft. I work for this truck driver and his 98' Freightliner has a 550 Catapiller turbo deisel with around 600,00 miles on it and its had some degree of shavings in it everytime the oil was changed. That truck will run by the way. Check the cam for stress marks, and a scratched type of look, that looks like traded paint so to speak. Make sure the lobes are under spec and arent worn down too far. Also check the valves for damage and make sure they are in adjustment. You are also giong to have to check the oil pump with such a severe amout of metal and see if it still works right. You will probably be ahead to flush the lines too. This stuff will probably require engine removal as well. I would go ahead and make sure everything looks good just to be safe, thats a lot of shavings even if they did build up over time. There are a number of things that could be wrong, I just cant pin point it by what you've said, im not quite that good. Sometimes i can though.

 

Thanks for the comments. I really do appreciate the help.

From what I've gathered, the majority of the metal came from the old worn out starter mechanism. They were worn so bad that the starter just free wheeled when I tried to start it. So my friend would stay on the starter button for like a minute until it started instead of fixing the known problem.

But, that's fixed.


This hesitation is very strange.

I'm thinking of all the things it might be, but can't put my finger on if it is it or not.

things like:

CDI Box not advancing right?
Carb really messed up? (idle screw is 2 turns out, float is set at factory specs)
Loose valve guides?
Cam lobes not true?
Cam retarded or advanced? (skipped a tooth?)


That's about all I can think of.
I'll get the cam out and replace it with a spare I have laying around.
I hope that does it.

I'm stumped still....