Hi Chaps,
I finally got around to putting in a new carby kit in my 180, its the fixed jet carb, I did order some chinese WT215 carbys to swap it and another over to a fully adjustable carb, but the ones I ordered did not look that good re quality, I took them apart, and felt that I would stick with the original one.
Even so, it tached out at 15200-15400, so I thought that was a bit too high. The metering arm was incorrectly set, probably by the previous owner, or maybe it was like that from the start, either way, everything was now correct but it was running far higher than I was comfortable with.
I had a look at the IPL, and the jet size is 0.45mm, high altitude jet option is 0.42mm.
I used to play around with race cars some years ago now, and would rejet the carbys depending on conditions of the day so I got out my verniers and realised I did not have any small jet drilling bits this size.
Further thinking found some needles at 0.46, then I came across one at 0.50, it was a needle that I would use for injecting grease into or past seal lips.
Gently rotating the jet on the needle caused the hollow end to ream out the jet orifice, taking out very small flakes of brass.
Once through, I checked the jet orifice under a magnifying glass, and it was smooth, and not rough, so back together it all went.
Warmed up and now it tachs at 12000, good 4 stroke out of the cut, and clean in the cut and dosent bog like it did previously, very pleased with how it ended up, still I think that an 0.47 or 0.48 would have been a safer start if it was available to me.
Hope that might help others who have a screaming 180.
Cheers
T