90cc minarelli overheating

Anyone having problems with this kit getting really hot? just ran mine 5 blocks at under 20mph and i can't even touch the cylinder. I overjetted, timing is not advanced, no airleaks, gas is rich, running a stock pipe for break in. Thoughts? experiance?

Re: 90cc minarelli overheating

Tell the specs.1

Re: 90cc minarelli overheating


90 imperial kit

race crank

24mm generic mikuni

stock magnum exhaust

Re: 90cc minarelli overheating

Jetting is the key... what intake? might need a better exhaust maybe...

Re: 90cc minarelli overheating

) Cupermcnewbster ( /

magnum exhaust on a 90cc? Gabe, hook up one of those derbi or yz80 pipes that end up on everything.

Re: 90cc minarelli overheating

Zack, its only for break in and i have something planned for later. I never had a kit run so hot...getting scared to run it.

Jetting is not a problem, I welded up an intake that matches the carb.

anything else?

Re: 90cc minarelli overheating

nope sounds like you have it there.

Re: 90cc minarelli overheating

btw, More in more out... so a stock pipe is going to make it run hot. good luck, I have a extra of rings if you need them.

Re: 90cc minarelli overheating

) CuperAWESOMO ( /

Sucks. Hate to go off topic but do you need peugeot stuff gabe? I picked up the two on CL. Just let me know if you need anything.

Re: 90cc minarelli overheating

Big main jets won't matter if you aren't opening the throttle and the needle is mixed lean. You shouldn't be running a stock pipe for break in, you should be breaking it in the way you intend to run it.

Re: 90cc minarelli overheating

yea had the same problem with my kit i upjeted super rich and slowly downjetted untill it would stop 4 stroking but of corse after about 5mins of WOT it hard seized and is junk now going back to my 75 polini and see if theres any perfomance differences never had any problesm with the 75cc

that kit just seemed so hard to tune and even when I was running super rich and it would only go like 20mph becuase it was so rich smoke still would pour off it wtf idk

Re: 90cc minarelli overheating

Yeah I've been running it rich so 4 strokes and smokes up a storm, needle is fat too.

My theory on running the stock pipe is to keep it out of a major powerband I want to break it in super slow. These kits looks like their waiting to seize!

You guys think a better pipe will help keep it cooler huh?

thanks for the input

Joe, Don't really need any peugeot stuff now thanks though.

Re: 90cc minarelli overheating

Josh what are your specs?

Re: 90cc minarelli overheating

You need an exhaust that is big enough to allow your moped to exhale.

Re: 90cc minarelli overheating

hey gt

moped-1979 carabela moped minarelli V1 engine

mods-90CC big bore kit

21mm phbg carb

32 rear sprocket 11 front

EV racing scopine pipe

18mm intake

nitrous kit (no I wasint using it)

Re: 90cc minarelli overheating

Klen Kahdidlehopper /

ive been running the same kit for the past 1000 miles.

i have never been able to touch the cylinder after going for a ride even just a short one. sounds totally normal to me

Re: 90cc minarelli overheating

V1 cases can be blazing hot as well. Normal.

90cc minarelli overheating

what oil to fuel mix? too rich of oil will lean out the mixture.

Re: 90cc minarelli overheating

for brake in run it 25:1 and jet it so it runs right on it buy punting more oil in their is more oit going out and taking the heat with it but you need a pipe to leet the heat and oil out

Re: 90cc minarelli overheating

Did you make sure to put the fan and shrouds back on? It'll run hot without that air flowing over it.

Re: 90cc minarelli overheating

Crossvalley Tonysieze /

yeah pipe possibly, and maybe going a tad faster than 20? its air cooled right? so 20 mph might not be cooling it as well. also, my minarelli is always running hot. i can never touch it either, unless i just rode in like 50 degree weather. sounds pretty normal.

Re: 90cc minarelli overheating

Thanks guys,

I'll try another pipe!

Re: 90cc minarelli overheating

I've got your answer. Just ship it to me here in Boston and I'll run it in our wonderful 20 degree air.

Should fix the overheating immediately.

Re: 90cc minarelli overheating

sweet, you can pick it up next month

Re: 90cc minarelli overheating

yeah v1 cases will burn your ankles...

Always a good idea to clean/open up the oil transfers in the case, and change your oil often.

Steel jugs get hotter and transfer more heat to your case.

always use the fan.

and 25:1 seems like alot of oil, try 32:1 for break in, maybe even 40:1. like someone else said, fuel cools.

And lastly a good expansion chamber exhaust will pull the heat out of your cylinder, if you wanna put it that way.

90's have always intrigued me... maybe someday.

I'm still trying to see how much you can get out of a Polini.

90cc minarelli overheating

#CrazyWayne™ rocks. #CrazyWayne /

I think tow big point's that needs to be looked in to or timing and compression or as my dad wood say hot and hotter.


Timing the stock V1 timing mark is at 23 deg BDC.

It kind of works like this The carb is a flame thrower .

The more time you give the flame it the hotter things/cylinder/head get.

We have no vacuum advance to adjust timing with or BIG flame throwers giving less flame/heat timing at WOT.

So in part we need to set or timing for WOT .

So by reducing flame burn time in the combustion chamber we reduce BTU/heat transfer to cylinder/head.

Thar or three ways to do this.

The biggest is spark timing try like 18deg's BTDC.

Next wood be Ex system back presser.

last exhaust port timing give it more timing up it 5 or 10 deg's.

And the bones is by dumping more flame in to Ex system.

The exhaust chamber loves it hot.

As RPM's go UP and UP it gets hotter and hotter

As it gets hotter presser goes up .

More heat and presser make shock waves move faster moving the power band up in RPM's at the same time = more power.


The higher the compression makes all hotter .

Compression you don't need HI Compression with a well tuned EX system ports and carb.

A good EX system will supercharge/raise compression by over stuffing the combustion chamber.

10 or even 9 to 1 shod be fine.

Bat back

Re: 90cc minarelli overheating

gabster, you should look into the bennasar pipes. many of them say 90cc and 80cc. check 'em out.


i'm put this one on my morini, it looks bad ass too.

i hope these links and images work

90cc minarelli overheating

#CrazyWayne™ rocks. #CrazyWayne /


I o most forgot Higher compression makes things burn faster to.

Giving faster heat /BTU transfer to cylinder & head.

Bat back

Re: 90cc minarelli overheating

what head? and they ake 2 fan sizes for the minarelli V1. are you running the smaller one?


Re: 90cc minarelli overheating

Klen Kahdidlehopper /

hahaha i have this kit on my v1 without the fan and with a stock magnum pipe and fully advanced timing. 1000 miles later and no seize its fiiiiine

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