78 maxi questions

recently bought a '78 puch maxi, approx 4000 miles, 70cc kit, proma

exhaust, 14mm carb. allegedly it came from arizona but is now residing in

boulder colorado. it ran pretty well for a month or so, though slow to pick up

on the low end. replaced the carb gaskets/cleaned the carb. intake gasket is

currently cork and seems pretty dry. upon spraying carb cleaner on

gaskets to check for air leaks the engine would die out rather than revving up.

piston seems to slap a bit when you let off the throttle and coast. tank

definitely has rust in it and needs to be cleaned. throttle speedo and brake

cables replaced.

recently on a longer ride (5+ miles) the maxi died out after running WOT for a

good bit. engine was making a high pitch noise, something like a squeak

squeal. possibly a gasket going? after letting it cool I made my way back

toward my house not exceeding 3/4 WOT when the engine seemed to abruptly

die at higher rpm and coming to a full stop. I was worried it had ceased but

after spinning the flywheel it moved up again, ran slow for the return home

but then seemed fine the next day. on the next long ride (3 ish miles) it died

out again but this time will not start back up. when trying to start the motor it

sounds really bogged out and won't start. I replaced the spark plug and

noticed the wire connecting to the governor (black box) was fraying and not

securely attached. not sure if this is normal.

I was hoping to get some recommendations on where to start. I know the

tank needs to be dealt with first of all but wonder if taking the engine apart is

necessary. I peeked through the spark plug hole and it seemed pretty

carbonized inside. Perhaps sea foam could solve this problem? worried that

timing is an issue. moped has no kill switch so I have had to result in

flinstoning the flywheel. I know altitude can have an effect on the engine so

possibly jetting could be an issue even though I have only heard it four stroke

maybe once going down a hill.

Ill attach a couple videos in my next post of the moped running, along with

how it sounds now during an attempted start up and tank/engine photos.

Re: 78 maxi questions

Probably Fred /

Sounds like you have partially seized kit,

Bad crank small end bushing, incorrect unchecked stock timing, or jetting and tuning.

There is no governor on your bike and your clutch is not tuned it seems.

Read all about kitting, jetting, timing and tuning on the wiki .

Sounds like a rebuild is in order/needed because someone just slapped it together. You're lucky it ran it all/got someone else's problems

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