E50 wiring question

Hey guys,

Have had some trouble getting my puch running. I installed a new condenser (solder type) because my bike would die once it got warm as if there was no spark. Here is my setup:

Treats 70cc kit

Mikuni vm20 with 130 main and 2.17 idle

Leanest needle clip setting

Proma circuit

17x45

The bike will start and idle, but seems very rich/laggy when I give it throttle. Plug is black and sooty. It has terrible low end and will eventually die. Got it to stop backfiring out the carb by resetting my points gap. Timing is set to 17* btdc, I've checked for air leaks, tried a new plug, so I'm thinking it's something to do with ignition. Can't seem to get this thing ripping. Here is a photo of the stator wiring. I think there could be a bad ground somewhere but I have no clue how to check that. I just redid my wiring as I eliminated everything but headlight and tail light, so everything seems to be in the right position. (edited)

IMG_20200620_145134.jpg

Re: E50 wiring question

todd amundson /

Fuck I can’t tell but the brass wire terminal seems to be installed on the point spring arm incorrectly, not insulated by a plastic screw grommet. I’d need to view one up close

Re: E50 wiring question

Here are some additional photos

IMG_20200620_150429.jpg
IMG_20200620_150439.jpg
IMG_20200620_150446.jpg

Re: E50 wiring question

Wesley Ambrosini /

Why not a jetting issue if the plug is fouling?

If not jetting then maybe a hotter plug would help

Re: E50 wiring question

For the wiring harness photo:

There are 3 wires coming out of the stator. One is the spark plug wire, one is the yellow wire (light power) and the last is a black wire (connected to one of my Killswitch wires. Here is how I have them arranged:

- Black from stator connects to blue/green (kill switch wire #1)

- yellow from stator connects to gray and blue/green (taillights) and black (headlight power)

I have ground my headlight wire on the top of my forks, grounded my Killswitch (the purple wire in pic) to the case, and my taillight has a ground in it. Does anything about this seem incorrect?

Re: E50 wiring question

The reason I haven't gotten to jetting is because it doesn't run right in the low end. I've had a few posts within the last few months about my setup not revving out like a proper 2 stroke (almost hits a wall at 42mph, regardless of main jet size) but it's running much worse right now than before so I'm just trying to get it running clean.

Re: E50 wiring question

Is your point gap right?

Re: E50 wiring question

anytime I hear backfire, I think timing.

Re: E50 wiring question

That's your issue. Get that fixed and work on getting it jetted right. If your points aren't gapped correctly it's going to run like ass.

Re: E50 wiring question

Yeah I need to buy feeler gauges for my point gap. Been using the cereal box method but if I can confirm my points gap is correct that would eliminate that. Or maybe it'll fix it, who knows. I'll try that and report back

Re: E50 wiring question

Got it to stop backfiring out the carb by resetting my points gap. Timing is set to 17* btdc,

He already said he corrected the backfiring in his first post. why are some of you dwelling on this. Read what he posted

130 seem huge for a 20m step that shit down

Re: E50 wiring question

Jetting sounds about right, plus usually VM carbs run good no matter what.

Those cheap stators have shit points on them, that's your problem. Rip them off and replace with genuine Bosch. Guaranteed that's your problem. The condenser was never the issue, dude.

Re: E50 wiring question

Re: E50 wiring question

roy jongejan /

is it a fresh carb? if not you might want to clean it, also, whats the intake manifold size?

Re: E50 wiring question

sounds like a bad condenser, won't let it rev up. try adding one inline externally to test. Theres a black wire coming off your condenser, is it melted to your lighting coil? hard to tell by the pict.

Re: E50 wiring question

How should I go about adding one in line externally?

Re: E50 wiring question

Get an old Bosch condenser from AutoZone, the kind with a mounting/grounding strap. Circa 1960s vw beetle.Mount it to frame ground, connect wire to the wire going into the ht coil . It can go anywhere. Cut the wire and solder, connect it to the spade connecter going into the ht coil. Doesn't matter, as long as it's on the ignition coil wire that comes outta the stator and connects to the ht coil.

Re: E50 wiring question

roy jongejan /

it might just be the sparkplug wire or cap

Re: E50 wiring question

Thanks for that! Going to try that today. Just to confirm, is the ht coil where the spark plug wire comes from? Or could you tell me where the ht coil is in my pics?

Re: E50 wiring question

> Graham Motzing Wrote:

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

> Jetting sounds about right, plus usually VM carbs run good no matter

> what.

>

> Those cheap stators have shit points on them, that's your problem. Rip

> them off and replace with genuine Bosch. Guaranteed that's your

> problem. The condenser was never the issue, dude.

The condenser is not the issue, dude.

Re: E50 wiring question

I'll need to order new points, but this set is new. The reason I think it is condenser over the points is because the bike ran perfectly before getting too hot and shutting off. All I've done to fix that was.try and solder a new condenser. Points are the same, but now with a new condenser it runs like shit. But I can try and find some Bosch points and give it a go

Re: E50 wiring question

The HT coil is the big black box on your stator. It has your spark plug wire coming off it. Normal bike setups have a coil for the points there and wires leading to another ignition coil to run the plug off.

Not giving me confidence in this ignition setup, which I was considering for a build I'm working on.

Re: E50 wiring question

Those ignitions fry every time you use them, to much head under the flywheel. Especially if you have the cover on the flywheel too

Re: E50 wiring question

I've run it with the cover off only, but it still kinda sucks. I'm lost with this bike, I guess I can try new points and an external condenser but I might just bite the bullet and buy a CDI and forget about all these problems

Re: E50 wiring question

Post on Buy/Sell for a 6 wire Puch stator and do away with all your problems.

Re: E50 wiring question

Just to update: I bought feeler gauges and set my points gap to 17/1000 of an inch, but it still runs like the video above. For those who have watched the video, does it sound like it could be a bad ground? If so, how can I check for that?

Re: E50 wiring question

Dirty30 Dillon /

That cheap replacement ignition set is to blame for 90% of your problems.

They are cheap, and poorly made. They get bad float/failure, and overheat very easily.

Re: E50 wiring question

Sounds like I'm going to have to bite the bullet and shell out for a CDI then. What a shame, roommate has this same ignition setup and his bike absolutely rips

Re: E50 wiring question

Update for anyone who might have this problem: I had used locktite on my points screw to prevent the points from walking, which ended up preventing the points from behind able to move horizontally back and forth, causing my points gap to be open way too long. I had set them with a feel gauge as previously mentioned, but the issue was the points gap staying open too long. I also added an internal condenser at the same time so maybe that was it, but I'm pretty certain it was the points. Thanks for the help, finally back to ripping this thing!

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account