Puch Dart - can't get running right

Dan O'Connor /

picked this up last week. It was posted here for sale but I found on CL. Hadn't been started since 88. I have it running now but still not quite right and I'm kind of stumped what to look at next. It's a 2 HP model, has a 1/12/340 bing carb, and the correct 54 jet per the manual. Everything is original that I can tell. Currently, it is tough to start, stalls if I try to slow it down to the point where the wheel nearly stops. I can't get it much more than 20 and feels like somewhat weak. It seems to be blowing a lot of white smoke. I did notice that removing the air cleaner tube and filter seems to make it run better. Let me know what I should look at next because this has me stumped. Thanks in advance!

Here is what I have done:

replaced plug, WC7 equivalent NC4 champion set to 16-18 range.

Cleaned fuel tank, replaced fuel line.

rebuilt carb including new float (float is parallel to the body when closed), needle ok and not leaking All passages are clear

Tested that gas is reaching carb and entering the bowl when the float drops

cleaned exhaust,cleaned intake and metal air filter.

cleaned grounding connections.

replaced tranny fluid to filler with type F

Tested for and fixed air leak at manifold to carb with O ring. Spray doesn't indicate any leaks downstream of the carb.

Checked the timing. Found/marked exact TDC with a dial indicator, using cigarette paper, found the points opening within the manual stated range of 14-17 deg, based on the flyweel being 360 mm. Points were cleaned and are set at about 16 degrees.(edited)

Re: Puch Dart - can't get running right

Richard Eberline /

points about 16 degrees. how about .016 for new points not old and not degrees.

Timing 14 to 17 degrees, do you own a degree wheel.

plug .022

points .017

timing 17 mm from tdc

Exact, not around or about.

Seals are dry rotted

tires are dry rotted

Chains are rusted

Rebuild your 45 year old motor

Re: Puch Dart - can't get running right

Dan O'Connor /

Thanks, fair comments. I have feeler gauges and the manual. The plug gap is 0.016-020. I set it to 0.018. The points read 0.016 on my gauges. The flywheel is 360 mm so one degree is 1mm and its set to 17mm (the manual range is 14-17.5 degrees). That is where the cig paper pulls out.

The tires are old but don't impact this, the chain the same but is lubed and functioning. I'll replace those after I sort the motor issues. I'm not looking to rebuild the motor at this point until I rule out other things which is why I asked. I'm not sure at this point is needs to be as it has low miles and appears to have good compression. I'll confirm that if you think that is the next step here. I'll have to go borrow a compression gauge from Autozone because I recently broke mine.(edited)

Re: Puch Dart - can't get running right

White smoke=burning tranny oil=tranny side crank oil seal bad.

Re: Puch Dart - can't get running right

♣Slew Foot♣ /

Pray your float on your carb is leaky and it's full of gas and flooding the hell out before you tear the whole thing apart

Re: Puch Dart - can't get running right

Dan O'Connor /

I don't think there is any problem with the carb. the float is new and it isn't leaking.

Here is a picture of the plug after a 1.5 mile full throttle run, kill engine asap with no idling. I was getting up around 25 on that run, so better than yesterday.

I'm not ruling out a rebuild, but not sure I have the bandwidth now to do it. I was looking on treats for a stock rebuild kit that has everything.

The motor was lightly seized initially. I freed it after sitting with fogging oil so I think it was just from sitting. I'd feel better about fixing it if it was only the top end but the prior post about white smoke has me concerned about the lower end as well.

plug.jpg

Re: Puch Dart - can't get running right

Plug pics should be taken from the end looking into the business of the plug .

Changing seals is not hard enough to scare a little girl away , if she wanted to ride . ;)

Re: Puch Dart - can't get running right

***Kim Jong Uno*** /

Darts have different seals.

Re: Puch Dart - can't get running right

> ***Vanilla Thunder*** Wrote:

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

> Darts have different seals.

What kind of different ?

Re: Puch Dart - can't get running right

Dan O'Connor /

Maybe this is better? Probably the best I can get with my camera though.

I'm not that bothered by the rebuilding but more of a time/money issue.

I scanned treats for a stock rebuild kit but everything was upgrade kits. I'll look again. I'd like to keep it stock. Plus I think I'd have to buy a few add'l tools plus the service tech manual. I have to decide if this is one I want to invest a lot into. It's really small, but also really complete and original with all the body panels. Thanks for your input.

spark2.jpg

Re: Puch Dart - can't get running right

That's a much better plug pic . Plenty good .

It looks maybe just a touch rich .

I don't know the fine characteristics of your model , so , wait for a more qualified opinion .

Re: Puch Dart - can't get running right

Dan O'Connor /

I got my compression gauge. After riding it a few miles it read 132 holding the throttle open. It does seem to be running better each time now. It actually started on immediately, which was the first time. It has been hard to start until now. Maybe it is kind of breaking in again after sitting for 30 years. I hit about 28 on a straight according to the speedo with 200 lbs on board. Hopefully, that compression is within range and I'll feel better about dumping another hundred or 2 on new tires/tubes chains, and a new horn/light switch.

Re: Puch Dart - can't get running right

I'd be satisfied with 132# compression .

Picture yourself sitting for a month . Would you do the best 100 yard sprint of your life , the first or even fifth try ?

Pretty much the same with machines . ;)

Re: Puch Dart - can't get running right

♣Slew Foot♣ /

run some Marvel Mystery Oil through it and check your pipe it's probably clogged or as a mouse nest in it

Re: Puch Dart - can't get running right

Dan O'Connor /

I think this is the issue. I checked the newly filled fluid and it was low. I fill it and watch it very closely this time. I assume this would also create a rich condition which would explain why it isn't running right. It runs about 5 mph better with the airbox off as well. From the above comment and reading I know the dart has an E50 with modified lower end. Are the seals the same as other E50's. Will this generic E50 seal set work also work on the dart? Thanks

https://www.lucky2strokes.com/Puch-E-50-Moped-Complete-Bearing-and-Seals-Pack-p/puch-e50-bearing-kit.htm

Re: Puch Dart - can't get running right

Dan O'Connor /

I just rebuilt the motor. I bought a generic seal set from treats. Ended up not using the 22MM crank/clutch side seal because it required a 3rd 17MM seal. For the bearing it took 3 6203's. The clutch side (normally 6203 NR) would not work. It required a special bearing with a 12MM outer race and 11MM inner race, otherwise identical to a 6203 NR. This is because it needs to sit over a snap ring - without that bearing you can't get the outside snap ring on. this may be specific to the 84 models, as my mini maxi spare parts guide for 83 has the 22MM seal.

Re: Puch Dart - can't get running right

Dan O'Connor /

The bike is back together. I've serviced the magneto and set the timing and checked ith with a light -17btdc. the only modification is a mesh air filter. this is because it wouldn't run decently with the stock airbox. that seemed a little strange. the carb is a 1/12/340, with a 2.12A set to leanest, a two ring needle and a 51 slide and a stock 54 jet. I ordered 2 jets from treats a 56 and 58. I had some micro drill bits and a lufkin micrometer. I pulled the labelled stock 54 jet and found a bit that just fit, it was a #73 0.024"inch bit. That bit wouldn't pass through the 58 or 56. According to myronmoped's drill bit OEM/chinese jet chart that puts it in the low 60's. I have to guess somebody drilled this out, I have no other explanation. I also have on hand a 1/14/160 with a 2.22 and the matching 14MM intake. Should I install the 14 or just use the 12 (or the 12 with the 14 intake)? What jets should I start with in either case? thanks(edited)

Re: Puch Dart - can't get running right

oh yeah, moped people hog out jets to make their peds slower. id put one size bigger than stock for your mesh filter.

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