Peugeot 103 tuning--- running reeeally hot

Andy /

Dec 11, 2008 11:29PM

Stock 103, non-variated, SHA 15, "top one" exhaust.

New clutch pad, removed three balls, adjusted the clutch springs for more tension/higher rev before catching. It revs way higher before engaging. Revs really high in general and performs soooo much better. Big time thanks to Lee at 1977 for giving me all kinds of advice on what I could do with my non-varited 103 (short of putting in a new crank and variating it). The bike goes WAY faster than it did before. With a little head start it climbs hills much better than my variated moby.

Question is.... since it's revving higher, it's getting REALLY hot. My first test drive was only a couple minutes long and it got dangerously hot. There are no leaks, jetting is almost rich at a 68 (it four stokes at the high-end when it's just warming up), plug is b6hs but it's old so it won't read accurately. What can I do to make the engine run cooler and more safely? All this over-revving will decrease the life of the cylinder and piston, no?

Totally stoked on all this new speed!

Re: Peugeot 103 tuning--- running reeeally hot

nerobro /

nerobro

Dec 11, 2008 11:38PM

how do you know it's overheating? Your motor may have never been getting up to temprature. ;-) You didn't change the gearing, so your motor isn't turning any faster.

Richer jetting can cool it off. Do a plug chop, see if you're running lean. I"ll bet you're not. And it's all just fine.

Re: Peugeot 103 tuning--- running reeeally hot

Andy /

akpasta OP

Dec 12, 2008 12:04AM

I've seized in the past so I'm really paranoid. My Moby is almost as fast, but is much cooler after the same distance. The only time it ever got as hot as this was when i ran it 17 miles WOT.

You may be right though. Bikes don't necessarily come from the factory running to their highest potential, sure as hell was true for my 103 LS U1.

should I use a colder plug?

Re: Peugeot 103 tuning--- running reeeally hot

nerobro /

nerobro

Dec 12, 2008 12:11AM

did you do a plug read? That will answer your plug question.

Motors can run VERY hot without any real danger. Especially if you run syntheic or castor oil. Motors seize when they get hot enough to break down the oil (and that's REALLY hot..) or if they get differential heating. For instance, if you rev a motor to redline on the centerstand.

Re: Peugeot 103 tuning--- running reeeally hot

Andy /

akpasta OP

Dec 12, 2008 12:18AM

Yeah, I gotta get some new plugs tomorrow, for a fresh read. Thanks for the advice.

Re: Peugeot 103 tuning--- running reeeally hot

Andy /

akpasta OP

Dec 18, 2008 08:26PM

Ok, so it's an sha 15.15, 68 jet, 4-strokes at WOT while warming up. My old b6hs plug was at the dark end of the 'okay' spectrum, which was before I took out the three balls, causing it to rev higher, and run hotter.

I picked up a b8hs and ran it around for a while. Drove a few miles and it was completely white. With a colder plug that shouldn't be the case, right? There was chalky shit on the arm, above the insulator.

Re: Peugeot 103 tuning--- running reeeally hot

.Allen Schlung /

Go to branch

allens

Dec 18, 2008 08:41PM

A colder plug does not = a cooler engine.

If you were over heating, your performance would start to deteriate as you ride your bike. You could also crack the top off and examine your piston. Look for excessive carbon build up or signed of predetonation (pitting at the piston crown).

Your timing could be too far advanced. That can lead to overheating as well.

Check for leaks.

Re: Peugeot 103 tuning--- running reeeally hot

Andy /

akpasta OP

Dec 18, 2008 08:50PM

thanks allens, that's good advice. There's a little divot at the piston crown, but I think it's from all the electrical work I've done (i.e. wrenching on the flywheel nut many many times with a piston stop in).

Re: Peugeot 103 tuning--- running reeeally hot

bemor187 /

Go to branch

brianwa

Mar 23, 2009 03:15AM

Your jet is too big. I have a pug non variated 3 ball clutch sha 15.15 4 petal reed. I am four stroking using the same jet. but still breaking in this motor that never got driven.

variator comes tuesday

Re: Peugeot 103 tuning--- running reeeally hot

Casey Griffin /

Go to branch

caseyg

Mar 23, 2009 04:28AM

I don't know that you can say he's too big.... air-fuel mixture is all relative to air temperature/density... which is also dependent on altitude as well... Unless you've actually ridden his bike lol and can verify that his jet is, in fact, too large for his current setup.. you can't really claim that..

Runnin' hot. Check for air-leaks. which could also throw your jetting off at certain RPM or all the time or whatever.

Also, with the SHA's, because there is no actual needle, it is possible (and generally true) that if you are running perfect in one area (WOT or idle) you're running lean or rich somewhere else...

I'd just check for air leaks, and run a bit juicy on both the oil, and the jet for a while...

Hot generally = lean... determining WHY you're lean is the fun part lol

MOPED ARMY

Login or Create Account