Heres a PDF of the manual, or a manual for the PHH series.

http://ddgonzal.members.winisp.net/w...Mikuni-PHH.pdf

Mikuni has website with a lot of info as well:

http://www.mikunipower.com/PHH01.htm

Even has jet recommendations for a 12A. Image is bit large. This is page
29 of the manual. They have scanned in the 30 page manual with links
to each page on here.

 

Thanks for that info Tim. By looking at that, the only think that I see Kory needs to do is go bigger on the main fuel jet. Other than that, I guess it should run decent as is.

 

Yeah I think his venturies are probably spot on for a 13B but the jetting is off. I gotta
believe the 13B needs more gas than the 12A According to Mikuni a 12a uses the
39 venturi and he has a 41 which should be fine for a 13B.

Kory, just remember to tune in the right order. Idle, progression, cuise and then
WOT. Each builds on the other. By progression I mean the transition from idle to
cruise.

Get that idle mixture setup right and at a reasonable rpm. Then
work out any transition issues going from idle to cruise. Usually involves adjusting
AP, pressure and/or floats. Then take it on the road to get loaded and WOT tuning
done. I'd do it on a large empty lot or road where you can pull off randomly to
tweak things. Engine sound, exhaust smell and plug color are the old school ways
to tune a carb. If you have access to a wideband that would be ideal I guess.

 

good advise! the great thing about the carb is that the old school way does actually work great. i have a WB and used it on the P port, but really only to check my work.

i also kept a little notebook, and went thru each part of the carb one at a time, IE i tried all my idle jets first, then the main fuel jets, etc etc. so i can go back and look at my notes and i can tell you what each part did. once you know what each part does, then you know what part to change.