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-   -   jetting seems SO close, yet not quite (http://www.chinariders.net/showthread.php?t=26535)

discochris 06-01-2020 08:07 PM

jetting seems SO close, yet not quite
 
Got the Mikuni clone reinstalled on the Enforcer...

Running a 115 main and 25 pilot. Needle in the middle position. Ebay exhaust. Stock airbox.


At around 900' above sea level.
Have tested a few different settings with idle screw and fuel/air screw.
Bike starts and idles just fine. Runs decent below half throttle, as soon as it gets to mid-throttle, it sputters and bogs.

I don't have a tach, so I can't tell you exactly what RPM it stumbles at. It feels so close, but still off. I've read most of the threads here, but can't decide which way to go next.

wheelbender6 06-01-2020 08:14 PM

Keep checking your spark plug. The electrode insulator should be tan in color when the jetting is right.

Wild Dog 06-01-2020 08:20 PM

Quote:

Originally Posted by discochris (Post 339386)
Got the Mikuni clone reinstalled on the Enforcer...

Running a 115 main and 25 pilot. Needle in the middle position. Ebay exhaust. Stock airbox.

Did you check the spark plug? I bet it is crayon white.

discochris 06-01-2020 08:44 PM

1 Attachment(s)
http://https://chris-berg.smugmug.co...50/i-GLXWMkB/Ahere's the plug

discochris 06-01-2020 08:45 PM

I put in another plug and it ran much better, but this plug was brand new. I bought it last month when I bought the bike.

The stumble is still there.

Megadan 06-01-2020 09:36 PM

Make sure it isn't stuck at half choke. That fine til half theottle and then bog is exactly the issue you will run into if it is.

Also, that 115 may be a tad rich with a stock airbox. Have a 112.5 main jet?

discochris 06-01-2020 09:53 PM

Not at half choke. This is with choke off.
You think it's too rich with a 115? I was thinking it might be too lean, looking at the plug, and noticing the engine seeming pretty hot.

I don't have a 112.5, I have a 110...

Megadan 06-01-2020 10:10 PM

Quote:

Originally Posted by discochris (Post 339397)
Not at half choke. This is with choke off.
You think it's too rich with a 115? I was thinking it might be too lean, looking at the plug, and noticing the engine seeming pretty hot.

I don't have a 112.5, I have a 110...

I live at 1100ft, a 27.5 pilot, needle 3rd slot, and a 115 main was what I ran with a pod filter and full exhaust in the warmer months. You might be fine with a 115, just a.thought since you have a stock airbox.

The only other thing I can think of is the float height might be off.

I only bring up the half.choke thing because it has bitten several members here, even me. Heck, I had the choke go to half on its own once when I hit a bump lol.

discochris 06-02-2020 09:38 PM

So I tried a 110 main. Bike ran EXTREMELY hot, and not well. Obviously lean.
Having already used the 115, I thought I would try a 120. No more stumble, bike pulls strong. Starts right up without needing choke.
(this was with the 25 pilot and the needle in the fourth position from the top.

However, idle was off - when I revved it in neutral, it wouldn't come back down, and it didn't idle well.

Turns out I appear to have lost the retaining clip that goes in the slide above the needle. Argh. I have no idea where it popped off to in the garage. I may end up having to order a whole new carb if I can't find it...

Megadan 06-02-2020 09:49 PM

Quote:

Originally Posted by discochris (Post 339534)
So I tried a 110 main. Bike ran EXTREMELY hot, and not well. Obviously lean.
Having already used the 115, I thought I would try a 120. No more stumble, bike pulls strong. Starts right up without needing choke.
(this was with the 25 pilot and the needle in the fourth position from the top.

However, idle was off - when I revved it in neutral, it wouldn't come back down, and it didn't idle well.

Turns out I appear to have lost the retaining clip that goes in the slide above the needle. Argh. I have no idea where it popped off to in the garage. I may end up having to order a whole new carb if I can't find it...

The missing needle clip would definitely explain the part throttle weirdness. Glad to hear the 120 main worked out.

As far as needle cljps. https://www.amazon.com/MIKUNI-VM20-3.../dp/B003CJW4W8

Never hurts to have spares. ;)

discochris 06-02-2020 11:31 PM

Not the C-clip. Isn't there another retaining spring thingy that goes above that?

Megadan 06-03-2020 02:02 AM

Quote:

Originally Posted by discochris (Post 339546)
Not the C-clip. Isn't there another retaining spring thingy that goes above that?

Ahh, you are talking about the V shaped retainer. You should be able to just borrow one from the stock PZ30 carburetor. They may be called different names, but they share quite a few parts.

discochris 06-03-2020 02:58 AM

Quote:

Originally Posted by Megadan (Post 339556)
Ahh, you are talking about the V shaped retainer. You should be able to just borrow one from the stock PZ30 carburetor. They may be called different names, but they share quite a few parts.

That's it! Thank you...

Megadan 06-03-2020 04:33 PM

Quote:

Originally Posted by discochris (Post 339561)
That's it! Thank you...

Did that work out for you?

discochris 06-05-2020 06:10 PM

Still working on it. Didn't realize that I needed to plug off all the air box hose stuff with the new exhaust... It's getting closer.


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