Some za 50 issues

So i sold a bike to someone. I put a k star 15mm bing techno boss onto a za-50. The install was perfect flipped clutch nub grinded ring gapped proper timing all that.

She is new to mo-peds. I explained that the bike needs to be broken in take it easy blah blah blah. She takes the bike on a 13 mile ride to and 13 mile ride back with her friend. Bike dies on the way home. Calls me because its running really rough when she gets home.

So heres whats up with it.

I go over and find that her frined has put a o ring infront of the bing to create a better seal?. one of the screws on top of the carb is stripped out and there is a small air leak there. I seal it up. and take care of some other things put in a new kill switch etc.

She changes the exaust pipe and puts allen bolts in to attach it. I get a call again because its weired i go over and find that the gasket and one of the allen bolts is gone and the exaust is loose. The hardware store is closed so i tell her to go buy a new bolt first thing.

The next morning she rides the bike to buy a bolt but cant find one and continues to drive to school with the bike as is. no the bike is running like shit and backfiring. Also not going very fast at all. She buys a allen bolt and puts it in same thing poppy and low speed. I say dont drive the thing anywhere ill come over today.

Before i go see it it seized is there anything else you guys can think of besides maybe a bad condenser. Could that small exaust leak cause the seize. Im also suspect of the gas oil mix. Even though i provided her with all instructions. I have assembeled the same equipment of many bike many times no problems.

Re: Some za 50 issues

sounds like a case of the stoopids to me. why would you ride your moped anywhere knowing you have a massive exhaust leak? yes, an air leak could cause her to overheat and seize...

sorry she didnt listen to you, maybe she isnt ready for a moped.

backfiring can be timing related, as well as fuel/ carb related.

so check for air leaks (obviously there are several potential spots according to your post), probably drain and put pre-mix in, check jetting, check to see the point gap is where it is supposed to be and re-set the timing.

if she was riding it rough enough that the exhaust came loose (assuming that is why she switched to allen bolts) then its possible the points or stator slipped too.

its probably just a massive air leak issue. hopefully the cylinder is ok.

good luck. maybe if you charge her for repairs she will get that she should listen to your advice during the break in period...

Re: Some za 50 issues

The last time i went by there were no air leaks. The only problem was the exaust leak.

Re: Some za 50 issues

Overpriced Parts /

If not timed 16-17 degrees before top dead center in this hot weather most times seize a new kit even if no air leaks anyway especially with a hi rpm hot running setup/pipe Like a boss. 70cc kstars can and do seize I saw inspected several this year alone all had stock timing and boss pipe or 6p pipes.

A za50 can hit hi rpm in first gear and can run hotter then a e50.

I usually don't sell a bike unless it is timed right, broke in for 300mi and

Run with a head temp gauge at wot to see if it can sustain under 400 degrees.

Up gearing a za50 helps keep down temps too.

Re: Some za 50 issues

The bike was timed at 17dgrees btdc. and maintained a constant temp of below 400 at wot,.

Let me rephrase. Since i would never ride a bike with a known exaust leak. What is the chance that riding with a decent sized exaust leak cause a seize. also can that ex leak cause enough of a raise in temps to seize.

Re: Some za 50 issues

Overpriced Parts /

Some people say yes though it never happened to me.

I rode with no exhaust twice for over 5 miles after they fell off with no seize and that was with a Gila and polini kitted bikes but they were highly broken in. I use lock washers and check my exhausts often now.

Kits seize under 400 degrees sometimes if not broken in at normal moped speeds for 300 miles and or the higher heat if any from a leak could be the straw that broke the camels back and I wouldn't use a bike as a long distance commuter until well broken in.

What was the tempature when she seized?

Even if perfact install, timing, bla, bla a kit is a racing kit with no gaurantee on the street or track

Well no matter now it's just a rekit away from running again

Re: Some za 50 issues

i havent even looked at the bike yet. I mean a scre on the stator plate could have come loose and retarded the timing or a condenser going bad who knows ill see it today and take the head off to see if it did in fact seize. That is where ill start. Hopefully its something less. Well see. As always ken i value your input and wisdom. ill post a update tonight or tmrw. Possibly some pics if we got a seize pic.

I dont know what the temp was cause this was a low budget bike for someone. I took a broken moby as trade and some cash. She bought a moby for 300 non running and was in way over her head. She lives in my town and found me on the forum so i took in upon myself to try to help her out. And i always love aquiring new projects. But thanks for the help.

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