Strange issue. Need advice.

[Fred1956]

Originally Posted by FDB

Hi guys.
I have a strange question.
I bought a 2002 300 Gasser and started refurbishing it.
The previous owner managed to fit a YZ250 exhaust header and silencer on it, but everything else motor wise is stock.

Checked reeds, did the jets to spec, the works.
Started the bike, and rode it, and it has a terrible crackling at 1/4 to half throttle. No matter what I do, it stays there. Raised the needle clip, messed with the airscrew, checked the choke, set the float level to spec, everything.
Everything pointed to a rich pilot circuit.

So I thought that by dumb luck, let me put a slide needle I have lying around from a 2006 KDX200 and the bike is absolutely perfect.
The needle that came with the bike is a N1ED. Not sure what the code is for the KDX needle but it definitely less taper (thicker).
So I have a rich condition that the thicker needle is sorting out for me.
Question is.. Why?
I checked the choke. Everything is fine there.

A few things bother me on the bike that I will get to soonest:
1. It does not have the OEM rubber that connects the carb to the reedvalves. It is just a random rubber pipe. And the carb is about 2mm from the reed fitting and not perfectly aligned to the reed fitting pipe.
2. It has a YZ250 pipe on.
3. The powervalves was set to fully open, and fully closed manually to check that that was not maybe the cause. Same rich condition on both those settings.
4. I?m not sure where the spark timing should be on the 2002 300 Gasser. But surely that could not have the same symptoms as a rich condition, and a fatter needle won?t make that better.
5. The bike is probably due for a new set of rings. But it has a ton of compression still and goes like crazy with the KDX needle.

I?m stumped.
I can leave the KDX needle in there and all will be ok, but surely something is not right and the KDX needle is a plaster on a cut. I want to fix the cut.

Any ideas?

What main jet is in there? I believe the N1ED is stock...If it works ggod then I'd leave the KDX needle in there & enjoy it....I run a Suzuki needle myself, some guys run Yamaha needles as well. + what does "plaster on a cut" mean (I'm not from around here )