PA50I Tuning after installing PA50II parts

Kenny Shinneman /

Aug 04, 2020 10:31AM

OK, so I have a pristine low mileage 78 Honda PA50I. Cleaned the tank, carb, new plug runs like a top completely stock. I Have now purchased and installed the following PA50II parts. Ramp plate, carb (stock #78 jet), intake, and reed valve. Still have stock exhaust and It starts right up and runs but sluggish. I pulled the air filter out and made a huge difference. revs up and not sluggish at all but I don't want to run without an air filter. I'm guessing the next step would be to either drill the holes out on the filter intake or put one on from an "II" . I have searched the wiki but don't see any details about when you have done these upgrades what to do to fine tune. Any tips/advise from someone that has done it with success please chime in. I'd like to keep it as close to stock and quiet as possible for the wife to ride. I appreciate any suggestions and input. Thanks. (edited)

Re: PA50I Tuning after installing PA50II parts

Chris . /

chrisleighty

Aug 04, 2020 10:59AM

You are still restricted by the pa1 cylinder and exhaust. You can drill out the holes in the brown tube or just cut off the top 1 inch with a razor blade.

Re: PA50I Tuning after installing PA50II parts

Beach Club Nick /

khool1499

Aug 04, 2020 11:14AM

The cylinder and exhaust are killer on the pa50i. Definitely need to get a stocko shocko or something

Re: PA50I Tuning after installing PA50II parts

Aaron Blair /

aaronb

Aug 04, 2020 12:00PM

As has been said, the biggest restriction is the pa1 cylinder. You'll need a 2 cylinder, I believe you might need to file a nubbon off the case as well so the 2 cyl will mount

Re: PA50I Tuning after installing PA50II parts

Kenny Shinneman /

colemanrider OP

Aug 04, 2020 12:29PM

I realize the 1 cylinder and exhaust is very restrictive and at some point might change that. But for now I'm hoping to get it running the best I can with the 1 cylinder. I'll cut of the top of the brown tube as Chris suggested tonight and see what that gets me. Is the stock #78 jet too rich for the restricted cylinder and exhaust?

Again, thanks for all the comments and advise.

Re: PA50I Tuning after installing PA50II parts

Beach Club Nick /

khool1499

Aug 04, 2020 01:08PM

> Kenny Shinneman Wrote:

> -------------------------------------------------------

> I realize the 1 cylinder and exhaust is very restrictive and at some

> point might change that. But for now I'm hoping to get it running the

> best I can with the 1 cylinder. I'll cut of the top of the brown tube as

> Chris suggested tonight and see what that gets me. Is the stock #78 jet

> too rich for the restricted cylinder and exhaust?

>

> Again, thanks for all the comments and advise.

The fact that removing the air filter (leaning it out) makes it run better points to yes, 78 is too lean with the shit stock cylinder and exhaust pipe. Seriously the pa50i exhaust is just the worst exhaust I've ever seen

Re: PA50I Tuning after installing PA50II parts

Kenny Shinneman /

colemanrider OP

Aug 04, 2020 09:08PM

After work I cut the top off the brown filter intake, ran a bit better. Looking at the shit stock exhaust with the crimped small outlet. Took a refrigeration tapered swedging tool and opened up the crimp to a nice round outlet. Revs very nicely now. But I think it still needs a leaner jet than the 78. Gonna try a few smaller ones to see if it improves. Anyone done this to give me an idea of where to start?

Thanks.

Re: PA50I Tuning after installing PA50II parts

Beach Club Nick /

khool1499

Aug 04, 2020 09:13PM

Fuck I wrote my post backwards, I meant 78 is too rich. Try like a 74 or 76

Re: PA50I Tuning after installing PA50II parts

Kenny Shinneman /

colemanrider OP

Aug 04, 2020 09:24PM

I knew what you meant. Gonna did some out and give em a try.

Thanks.

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