Airsal 70CC PUCH BLOWN

I recently installed a 70cc airsal cylinder kit on my '77 puch maxi. I have a 15mm bing that was jetted to 82 with an intake and exhaust on the bike. After about 100 miles...i hear some metal noise then blurp...bike stops...won't start. push it home 4 blocks and pull it apart...the cylinder/piston are thrashed. Massive amounts of scoring on the bottom side of it. Mix ratio was 40:1. Any ideas? Is this common with this kit? I know i need a new cylinder/piston kit, but damn...$120 down the tubes.

Re: Airsal 70CC PUCH BLOWN

Post pics of the piston and cylinder.

Re: Airsal 70CC PUCH BLOWN

Were you running at full throttle when it happened or at a constant throttle position? Could've had a lean spot somewhere in the midrange of your throttle and seized it.

Re: Airsal 70CC PUCH BLOWN

this is the piston... :(

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Re: Airsal 70CC PUCH BLOWN

and the cylinder

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Re: Airsal 70CC PUCH BLOWN

I was running at WOT. Maybe for 1.2 miles then BAM.

Re: Airsal 70CC PUCH BLOWN

) Cupermcnewbster ( /

Possibly an exhaust leak or it wasn't jetted properly. How were your plug chops?

Re: Airsal 70CC PUCH BLOWN

You seized cause you were running at WOT for 1.2 miles. Did you break it in before you did that?

Re: Airsal 70CC PUCH BLOWN

Yeah I don't run WOT for 1.2 miles even when broke in. You have to variate your revs a bit.

Re: Airsal 70CC PUCH BLOWN

I ran it 500 miles before opening it up. I ran it a couple times before this stretch at WOT without any problems. You can run a stock setup for hours on end at WOT...why would a kitted bike be so sensative to this?

Re: Airsal 70CC PUCH BLOWN

cause stock parts were built to last. kits were designed for racing. you can make them last for a long time if your not constantly pushing them to the edge.

Also, how long did you run the bike at WOT before doing a plug chop and did you do the chop immediately after cutting the engine?

Did you chamfer the edges of the ports to smooth them out? How does your ring look? Busted? Cause it looks like it got caught on the exhaust port.

Re: Airsal 70CC PUCH BLOWN

Re: Airsal 70CC PUCH BLOWN

I run that kit and use an 88 main jet with the same carb running the high flow air filter... What air filter were you running?

Re: Airsal 70CC PUCH BLOWN

Also what pipe. What plug are you running? The reason I got a 70cc kit was so that I didn't have to run at WOT to do 30 mph.

I'm running an Airsal 70cc on an E50 with 15mm Bing carb and intake, Proma Country (Biturbo) exhaust with the high flow filter. I also use B8HS or B7HS. Running B8 for the summer because it's a cooler plug. 88 Main jet. Needle setting is in the middle. I always have varied my revs and never really stayed in WOT for more than enough time to pass a car or something... I cruise around 35-40mph. Closer to 35.

Re: Airsal 70CC PUCH BLOWN

I installed the kit...ran the bike for about 400/500 miles gently...only smoothly opening up the throttle the whole way. After about 200 miles i pulled the plug and it had a nice brownish/black tint. It was definitely not lean. I then ran it for another 200/300 miles and pulled the head off and just wanted to make sure the cylinder was OK. Everything looked good...so I figured I was golden at this point. I ran the bike for probably an hour or so opening it up a few times for about a mile or 2. Parked it...came out the next day...ran it fairly 'normal' again...but then going through the liberty tunnel in pittsburgh....i got out the other side and BAM. i heard a weird metal noise. I stopped the bike and let it cool off for a good 30 minutes. Tried to start it up again...and nothing. It was really hard to pedal to start...so at that point i knew the piston was hanging up. I may have just ran it too hard too soon. I didn't grind anything down on the bike...no smoothing out of the exhaust ports or anything like that. I didnt know it was crucial. This is my first kitted bike by the way. I'm willing to try this same kit again...as it did run awesome when it was running correctly...but maybe i'll go with a modest 60cc kit instead? any suggestions are welcomed.

Re: Airsal 70CC PUCH BLOWN

Oh, and I'm using a stock 50cc high compression Puch head...

Re: Airsal 70CC PUCH BLOWN

15mm BING 82 main jet. 15mm intake. Needle is 2nd groove from the top (mine has 4 grooves). I got the intake from treats hq as well as the exhaust. B6HS plug (stock). Nothing too fancy really. I suspect I just killed it due to running it at WOT too long. Cruising at 35 didn't stress the bike at all...

Re: Airsal 70CC PUCH BLOWN

What air filter? If it was a high flow you were way lean on the main jet...

Re: Airsal 70CC PUCH BLOWN

Also, Tim from TBS has an Airsal kit for sale. I think it's new or only has a few miles on it... You should hit him up. You can probably get it for less than a new one...

Re: Airsal 70CC PUCH BLOWN

what's TBS? and who is Tim? I'll def. try again. It is a high flow... Maybe it was too lean...but the plug chops looked ok and it ran ok.

Re: Airsal 70CC PUCH BLOWN

It was probably lean. The main jet doesn't really kick all the way in until you are blasting it so it would run okay at lower RPMS... Did you just check the plug color or did you do a plug chop at full throttle?

What pipe is it?

TBS is the cincinnati branch of the moped army and tim is a dude that's in it... :)

Re: Airsal 70CC PUCH BLOWN

The pipe is a homoet 6p. I bought it with that pipe on it. I might try a 60cc kit the next time around. I'm having a hard time finding the Airsal kit anyway. Know of anywhere I can get one?

Re: Airsal 70CC PUCH BLOWN

I'm about to roll but if you just pull your plug out without doing a chop at full throttle, you can't actually tell if the main jet is lean... Unless it's hella lean, which your probably isn't. With your new Airsal, start with a 92. Buy 88, 90 and 92. Once you break it in rock the 90 when it's cold and the 88 when it's hot and you'll be rocking. Also, move to a cooler B8HS during break and in the summer and a B7HS in the cooler months. That should make you happy dude. If you are running a Grand Prix pipe you might need a lower range like 86, 88, 90, i would assume.

Re: Airsal 70CC PUCH BLOWN

Contact timr@mopedarmy.com... He'll hook you up. With the homoet run the 88, 90 and 92 range...

Re: Airsal 70CC PUCH BLOWN

Interesting... your first post says "after 100 miles" every post after that the miles seemed to grow,

You said the plug looked dark brown/black after 200 miles.. doesnt sound like you did a chop .

Sounds to me like you never checked the plug the right way and were too lean add that to a too hot of a plug and wide open for a long time = meltdown

Re: Airsal 70CC PUCH BLOWN

break in blah blah i did 65mph on my new kit ( 50miles maybe) yesterday, first you need to be close on jetting then run a little rich, i like to polish all the chamfers so they're perfectly smooth so the rings will glide over them with no Micro sized edges to wear the rings or catch them, and i run about 40:1 oil. Run a pretty hot plug too so you _can_ run rich

Re: Airsal 70CC PUCH BLOWN

Re: Airsal 70CC PUCH BLOWN

"cause stock parts were built to last. kits were designed for racing. you can make them last for a long time if your not constantly pushing them to the edge."

I've run all my kits WOT for up to 10miles or more at rallys, the latebird rally was 80miles of non stop blasting, i had to fill up twice and ran out of gas once too, so 3 full tanks of blasting.

If you tune it right u can hold WOT for days, remember the faster u go the better ur cooling fins work.

u seized cuz u where not tuned right.

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