Magnum GP .65 runs rich

[crankestein]

Got this Magnum GP .65, idles perfect, until all fuel runs out, best idle of all engines.

The problem I am having is during transition and at WOT the engine runs extremely rich/ gurgling and takes a few seconds to finally clear out and then somehow get a good top end. :Confused:


The strangest thing is the needle is completely closed (CC), even swap needles from a O.S. / K&B / and a Magnum XL, and still does the same problem.

Is there something I need to re-adjust on the carb so the needle leans the mid-range and top end?

:(

[WintrSol]

You can remove the needle assembly and fuel inlet 'banjo', and have a look at how well the needle seats against the fuel inlet. It could be none of those needles seat properly, or the needle assembly just won't let them because of damaged threads or other problems. Make sure you watch for any seals, so you can reuse or replace, as needed.

btw, the photos show what appears to be an O ring on the needle, which should probably be going inside the seat barrel, so the needle may not be fully seated at all.

[crankestein]

My bad about the needle photo, that is not the one that came with the engine.

I was testing out several of them, and none worked, I took apart the carb, but everything seemed as it should.

The seller told me to send it back, but he is refusing to pay return shipping. I think the needle was replaced, the engine is flooded all the way to full throttle and never clears out.

[WintrSol]

With the carb apart, needle seat removed from carb, you should be able to determine if any of the needles will seat in the fuel jet, closing it off, Just turn a needle until it stops, and look in the end opposite the needle with a bright light, to see if the needle protrudes into the jet area, like it's sticking a tongue out. Alternative is to search for repair parts for that engine make - sometimes the same carb is used on multiple models, so don't focus only on that one.