Puch Polini, How Hot?

) Cupermcnewbster ( /

So I've had a polini for awhile now, and I soft seized it about 2 months ago, and I determined the problem to be electrical (crappy spark). I had it all dialed in prior, and before the issue, it was very fast and quite reliable. The cylinder never really got that hot running like half advance timing.

Today we put together a ported polini on my magnum and it FLIES. Its actually pretty crazy, easily doing 50+ on 14x36 gearing. The jetting appears spot on (19 phbg, 106 main, w7 needle fully rich) with nice chops and good power throughout. I am running full advance (as per creature advice), but this shit is getting HOT. Its not quite as hot as when I seized it, but its up there, and I worry how long it could take the heat. Is this how the racers run it, or is there something to cool down? I know full advance is notoriously hot, but I know some dudes run full advance on polinis for days at WOT. I don't really want to seize this one (as it isn't mine) but I don't want to sacrifice too much power.

All advice is greatly appreciated.

Setup:

Polini (ported, case matched

malossi 4 petal

19 phbg racing (106 main, w7 needle full rich)

motomatic n8p

full advance with small gaps (perfect spark)

14x36

I'd guess its topping out around 55 based on my prior setups.

Re: Puch Polini, How Hot?

how hot is too hot?

how do u know its too hot?

Re: Puch Polini, How Hot?

) Cupermcnewbster ( /

I dunno, its just feeling really hot. I'm not sure a good way to measure the actual heat of the cylinder/exhaust, but its a bit hotter than all other setups I've run in the past. I'll see if I can get a heat gun from my friend and get a quantitative reading.

Re: Puch Polini, How Hot?

i just started experimenting with with a laser temp reader i'm around 180 F normal blasting around the streets and pull over, a similiar one i saw at 200 F, different intake though, makes me think that intake lengths/shapes/material will run your cylinder cooler or hotter, obviously cooler will provide best power. then an ok 2 speed polini i saw around 160 F, all preliminary tests though. pipe header around 270 F

I hope your doing a real "plug chop" this is from my bike with a 92 main, accuracy... the smaller the black ring on the bottome of the insulator the better the jetting for maximum power, after this i dropped to a 90 and I run 6 plugs for a totally white unsulator, faster then ever...

Re: Puch Polini, How Hot?

) Cupermcnewbster ( /

dang, thats pretty official. I haven't done perfect chops like that yet, but it seems alright from preliminary chops. I'll work on it this week and see what numbers I get on the temps.

So brandon, the gila is at 180-200. Do you by chance know what would constitute a temp reading that is "too hot"?

Re: Puch Polini, How Hot?

yeah wat brandon said... how did u cut open ur plug? just curious it seems like it might take along time with a dremil cutoff wheel.

also where did u learn about the ring at the bottom of the plug? seems like a good method.

Re: Puch Polini, How Hot?

oh and brando when i get back in town can we heat test a bunch of bikes I really want to know what my polini is running at as well as bellas.

Re: Puch Polini, How Hot?

lets do it, 2 stroke tuners talks about this plug chop easier than i though thats why i haven't done it before, but yeah just carry two plugs with you do a long wot and switch the plug out go hope dremel cuttoff - 4min, whoala! I want to check how the 90 jet looks so i can see the comparision.

I can usually touch the fins for a good second under normal riding conditions but long WOT i'm sure it gets over 200. I imagine super hot would be like 240F + this being the outside of the cylinder wall but this would mean your lean so, worry aboout the plug chop because you can't do anything about it being too hot if your jetted correctly, besides taking it easy. i'm sure new cylinders will run hotter at first anyways

Re: Puch Polini, How Hot?

Re: Puch Polini, How Hot?

nice.... i haven't looked at that page since i 1st got into peds, lol it might be time to review the basics.. cheers!

Re: Puch Polini, How Hot?

expensive ass way to tune. I assume you do lazy plug chops till you get brown on the out side than start to cut to get it even closer.

Re: Puch Polini, How Hot?

) Cupermcnewbster ( /

brandon, what kind of timing are you running? I've heard full advance runs hotter, but also is more powerful.

Re: Puch Polini, How Hot?

it runs hotter cuz it brings the heat into the cylinder more, it will NOT give more power, it give more torque and less peak rpm.

if u want more top end u might want to retard it slightly, however i find IMO that puchs run best at full advance, then from there u can play with the points gap to get the perfect timing.

full advance on a puch is only like 1mm btc

Re: Puch Polini, How Hot?

i find it pointless to do a "plug chop" on the street it shows almost nothing, i takes a lot of miles to even get build on the face of the threads which is what your supposed to read, I think almost everyone runs too cold of a plug because they're reading the insulator and electrode or something and they want color on it, insulator should be WHITE. I jet off a guess since i've been so involved in many mopeds/ parts then i tune it by performance and feel.

I feel like you should run a plug as hot as possible before you have pre ignition/dednoation because plug rating does not effect engine temps and you'll never foul.

seems like a cheap way to tune to have a high performance realiable machine thats jetted correctly and i'll never have to buy to new plugs.

I'd like to see elliots... Advanced/Retard doesn't really mean anything since it's dependent on the size of your gap right? moving the stator is only for small adjustments for _advancing_ or _retarding_ your gap's timing?

Poor timing will cause heat problems i'm guesing

I've only messed with my timing on my new bike once since i've never found perfect timing. everybike is differnt but i made a small gap and advanced and it was shit, opened gap and advanced it's been really fast. I thought your supposed to advance as much as possible for peak performance, in most cases. top end bikes will need slightly retarded timing compared to if it was a city bike. (cdi curve...)

IF your bike runs really well and you have tiny alluminum specks on your plug from the crown your advanced maybe for peak performance(advanced-> slight dentonation) IF it runs really bad you could be too advance or retarded.

I'm going to adjust for really fast and try to get the specks then back off on the stator.

I heard if you points make a spark you condensor it bad??

Re: Puch Polini, How Hot?

) Cupermcnewbster ( /

so brando, you are full advance with a big gap? When you say slightly retarded, I've always wondered if this mean retarded from stock, or from full advance. I put on my proma today and its still getting hot but chops are still pretty good, a tad rich even. The power is quite impressive. I think I like the 19 better than the 21 on there.

Re: Puch Polini, How Hot?

from stock. Stock timing on an e50 is 0.80-1.2mm BTDC. Elliot, when you said fill advanced is 1mm, I'm guessing you meant 2mm? Since advanced would detonate while the piston is further away from TDC. I have mine set at 1.5mm and gap at .018" which is on the small side of stock for and e50 (.016"-.024").

Re: Puch Polini, How Hot?

"Elliot, when you said fill advanced is 1mm, I’m guessing you meant 2mm? Since advanced would detonate while the piston is further away from TDC."

not sure what that means, but yeah full advance i guess is 2mm BTDC i don't know. all i know is that my stator is all the way advanced, and when my points open its around 1mm-1.5mm before top dead center. can't remember exactly. and the gap is very small.

I am still under the impression that the points gap is not how u are supposed to change the timing, its something different that also effects timing.

Re: Puch Polini, How Hot?

ok so i just re read the ignition chapter of Abells book since there have been alot of ignition Q's on the forums latly around performance.

To all READ that chapter again. Its good, and there is slot of info in there, i won't go into it all but here are some interesting tid bits:

points are only to time the bike the duration is of no concern but some cdi have too little duration

so if u have a movable stator and points set the movable part and play with the points to time it.

timing must be more retarded for more top end and more advanced for more low end (basically) the more performance ur motor the more retarded from stock u want ur timing (now i'm really curious to where mine is set too)

plug gap should also be made smaller than stock on high performance motors to better atomize fuel at high rpm sine the coils can't generate the power to spark as strong at high rpm. larger gap is better low end, smaller gap better top end.

there is slot more in there, read it!

Re: Puch Polini, How Hot?

My maxi with Polini runs around 160 on the cylinder and 190-210 on the head.

Re: Puch Polini, How Hot?

guess what happend to me on the ride last night

2 jets smaller

Re: Puch Polini, How Hot?

TWO jets smaller!!?!? Wow, talk about a fine line...

I'm guessing your bottom end at best is completely scrapped? Any pieces get into the transmission?

Re: Puch Polini, How Hot?

Hellarad Johnnny Johnnny /

dude, if your bike is ruined, that will be a huge shame. that thing was awesome.

Re: Puch Polini, How Hot?

Thats why its better to not try and tune until your insulator is white on mopeds. Light brown/tan maybe a little rich in theory, but its safer in reality.

Re: Puch Polini, How Hot?

y did u run a hotter plug also? and that sux, don't worry guys its not ruined.

Re: Puch Polini, How Hot?

Hes just showing that 2 jet sizes smaller made that big of a difference in the color of the insulator and that black ring is gone. He cut the plug with a dremmel as before I believe...

Re: Puch Polini, How Hot?

Yeah, but those specks of aluminum on the insulator means something is melting.

Re: Puch Polini, How Hot?

) Cupermcnewbster ( /

Brando said "I

Re: Puch Polini, How Hot?

hotter and leaner, timing was off too, plus i practiced my new _trick_ doing 50mph next to a concrete wall with sparks then the non grand finale of blowing up a little later

sorry everyone i got the last one; lets just say gila 2.0 will run jeting/plugs a little safer in a few days here along with improved alterations...

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