JCP Swinger 2 timing and results

Still very new to the game, and after fiddling with the clone 12mm carb, I was good at wot, running fine, but 1/4-3/4 throttle would cause it to run wrong, seemed rich around 1/4 throttle and I think it was 4 stroking around 1/2-3/4 throttle so I wanted to go back and adjust timing (should’ve done first maybe but I was a little nervous about messing with timing)

After much frustration, and wanting to set the whole damn thing on fire when the points wouldn’t open, finally set timing to 17 btdc. Idled to warmup and then gave it throttle and noticed two new things:

1) Rear wheel used to constantly spin while idling on stand, now it doesn’t at all,

2) Plumes of whitish-gray smoke shoot out the exhaust now, much more than before.

Aside from the timing, I didn’t adjust anything else. Trying to figure out if it’s too rich now? Thinking of doing a plug chop but wanted to see if I’m missing something that should be done first?

Any and all feedback is welcome and appreciated.

Sidenote: image was spark plug before adjusting timing. Seemed black and sooty like too rich, not sure though.

50165A2C-464A-4B1D-B50A-EBA0E2415812.jpeg

Re: JCP Swinger 2 timing and results

Super rich...

spark-plug-color-chart_3.jpg

You can move down a jet and see if that helps. If you do not have any jets you can at least lean out the needle on your slide. Moving the clip up will lean ot out. Just move one notch at a time. If you are on the top notch and it is still to rich, you will need to invest in some jets. Get a few of them to play with and find the perfect one.

Re: JCP Swinger 2 timing and results

Thanks a lot for this response! I ordered some jets, 5 pack of even #’d 60s, we’ll see if any will work. Also ordered a couple ngk b6hs spark plugs, going to set it at 64, move up the needle position, and go from there.

Also ordered 24 coke slide and may out that in too. Should be in this weekend. Again I really appreciate the input!

Re: JCP Swinger 2 timing and results

Something I've come to realize is that more recent moped motors are rather finicky about the amount of oil in the gas. Too much will produce a carbony spark plug and poor performance.

I have no idea how to determine the percentage of oil in the gas. It's possible that there isn't any way to do that.

Mark Kinsler

Re: JCP Swinger 2 timing and results

Makes sense I guess. I tried to err on the side of caution with the first tank I ran through it, between the altitude and not knowing enough about the bike I didn’t want to skimp on the oil. Didn’t go crazy, probably a .3 oz more oil over what the ratio called for in a gallon of gas.

Stayed pretty much right on top of the ratio for the second tank. Looking forward to more tinkering with the jets when they get here.

Re: JCP Swinger 2 timing and results

Overpriced Parts /

Pitch the 12 mm clone for who knows what atomizer is inside of it/just whatever diameter they chose to pick and get a used 14 mm bing, that’s what came with your bike if was a 2 HP

If not a two HP and it’s restricted and it’s got a restricted pipe, you’re gonna have some issues never get the jetting right, or go fast ever

Open port square intake port 2hp cylinder e50s like 14mm bings with 222 atomizer 70-72 jet and metal mesh filter, The stock junk air filter with white resonator tube confuse the jetting too so run metal mesh filter or run none initially to jet close,

If it’s a 2hp Cylinder and pipe (and pipe and header is clean/unblocked, cylinder, rings and piston are in good shape) and you run what I just said to do you’ll hit 35mph on flat with 16x45 gears, you can tune clutch and stuff later, You said you retimed it,

Did you do something similar to what’s in this:

https://www.mopedarmy.com/wiki/Puch_timing

If not I suggest you read the whole thing, Service your magneto and get the timing Perfect with timing light before you jet

Re: JCP Swinger 2 timing and results

Thanks for the response! Damn clone carb...I did order the mlm velocity stack air filter with the jets the other day, think that’ll work? Also got a 224 atomizer because there weren’t any 222’s on treats.

As far as the timing, I did set it according to that wiki. I used a screwdriver though so it may be a little off but I marked and re-marked the actual screw driver when searching for tdc to try and make it accurate. Will go back and check again and get a timing light before jetting.

Got the original JCP bill of sale from ‘79 and I can’t remember exactly but thought it said 2hp on there, will have to double check. Cleaned the exhaust pipe of a lot of deposits, no huge buildup but it needed a wire brush scrubbing. Thanks again! Will update when the parts come in and send some shots!

Re: JCP Swinger 2 timing and results

Pushrod Fifty /

If it was as stock setup I would say that the needle clip should be raised 1 notch to lean out the 1/4 - 3/4 throttle position. But as mentioned, getting a real Bing 14 should do it. There is a wiki somewhere that tells how to derestrict tbe pipe and what jets to use.

Re: JCP Swinger 2 timing and results

Careful with that velocity stack. It is gonna ram air into your carb if you have it facing forward. Start high on your jetting and work down. Like 6 or 8 higher than you are now with just that stack on there.

Re: JCP Swinger 2 timing and results

Ooh good to know, thanks! I might need to order different jets then. No marking on the one that’s in the clone carb, not really sure where my benchmark is. I’ve heard the bing clones come with a 72 jet, anyone else heard/ seen that?

If that’s the case, the 5 pack of even 60s won’t do me much good with the addition of the new air filter.

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