Cpu fans

I'm going to try mocking up a computer fan this morning for added cooling on my ciao..My temps hit 400 in less than 2 miles riding 3/4 - WOT.

Has anyone has success doing this?? If so much did your temps drop?

Ill post up my results after I try it.

Re: Cpu fans

Ill get this out the way before I get the obvious responses.

Points and plug gap are set correctly.

64:1 amsoil

Jetted slightly rich

No air leaks

I probably only have 150 miles (if that) on my new polini kit. So I'm guessing my temps are high still because its still in "break-in" period

Just wondering about the fans, more cooling never hurts. Just don't know if it will help...

Re: Cpu fans

Christian Giron /

retard timing?

Re: Cpu fans

♣Slew Foot♣ /

try a colder plug say an NGK 8 no resistor boot or plug, run a little rich on ratio, retime and retune, you must be a little advanced to get that kind of temps recheck the TDC manually and use a depth gauge or degree wheel and then the airmix must be high in airflow.

as far as wondering anyone with a neamex suit wana try running a fishtank pump to either the fueline or a modified ventcap?

i would think if you lower the jet and pressurize it, it would atomize more fully and exrtra fuel/air never hurts

an encarwi 12/10 out proforming a19mm whaaa?

Re: Cpu fans

Try a fan from a motorcycle radiator it'll work a lot better than a computer fan.

Re: Cpu fans

Your temps are high because something is wrong, fix the problem and then you won't have to worry about fans. The stock cooling fan moves way more air than a little cpu fan.

Re: Cpu fans

Grey L Wrote:


> Your temps are high because something is wrong,

> fix the problem and then you won't have to worry

> about fans. The stock cooling fan moves way more

> air than a little cpu fan.

You didnt mention anything about running WOT plug chops.

... you have an SHA or some other small carb right?

if so:

Small diameter carb + kit(higher RPMs) == really high air velocity in the carb body => much leaner at the "higher than stock" top speed.

Re: Cpu fans

Modify a scooter fan to replace your stock fan.

Terry dean and Ciao ciao did a fan mod...

Re: Cpu fans

Retard the timing and get the pipe working harder, that will get the heat out of the engine AND move air over the fins faster because you will be moving into the airstream faster...

Re: Cpu fans

Re: Cpu fans

that's fucking dumb. sorry but it is, a little cooling fan. jeesus.

and how many times are people gonna have the same dumb idea.

at least you didn't suggest using it in front of an air intake as a supercharger. fuck.

i hate your cpu cooling fan idea. if you run a 36V ignition coil and then have a regulator bring it back to 12, then you should run a cooling fan, but on the regulator box. man that'd be siiiick!

Re: Cpu fans

Hobbit fanThe fan I used with my hobbit was a scooter radiator fan. 6inch diameter.

The hobbit stator puts out just enough power to run it directly, but I had to add a battery/redo wiring to charge battery/add regulator to make it really perform well.

It works great, but you need to push a lot of air to make a difference.

My temps dropped 50deg overall.

Since your setup can adapt a better flywheel fan, that's the way to go!

Easier, less stator draw, huge cfm flow, pow! (edited)

Re: Cpu fans


Re: Cpu fans

Thanks everyone for the input..

This morning, prior to everyones comments, I installed one for the hell of it. Its rated for 76cfm which is actually on the high end for these(I believe). It was one of the best ones at radio shack, pretty good size. 2000+ rpms. I wired a switch in first so I can kill it should I need to..

The only problem with it is the fans rated 12v Max (6v "start" tho). My ciao being 6v hardly spins it at low idle but as the rpms climb that thing rips! I shut it off mid ride, the wind alone propels it really well.

It had little to no affect on my WOT temps. Although the temps do seem to drop much faster when I let off the throttle now, Almost as much as chocking it would before the fan. I didn't have to choke to cool it down once and it was pretty hot this morning so that's a plus! Ill get some me metal screen over it so I font crack it up with the first rock that hits it.

Next on to timing. Only way I know of setting timing on a Vespa is the points. I'm set at .018 inch which is actually pretty advanced. Hopefully retarding it to .015 or so will keep the heat in the pipe.

Re: Cpu fans

@Aaron, correct I have an sha. I realize only having a main jet really limits tune-ability. And what you said makes sence. Is the only way to correct it, by upjetting? So it'll pretty much 4t though out the low/mid but will be tuned right for WOT?

@Adam, the contra spring will certainly help my low end, but I don't think it'll affect WOT at all. I'm going to buy one as soon as they got them back in stock, And a polini variator + malossi belt if I can get doe funds.

Set my point gap to .015inch before I headed off to work. Didn't try it out cuz I wanted to let the loctite on the variator nut dry for a while. If the bike starts with this small of a gap hopefully it'll do the trick...

Ill probably grab a colder plug on the way home, run a few plug chops, and re-jet if nessecary. I'll post my results tomorrow. Anything else while I'm at it?

Re: Cpu fans

I think the fan should be the last thing to do.

First you get everything ripping and jetting/timing/compression/ tranny etc,

Then add cooling if you even need it.

Otherwise youll just chase your tail...

On the hobbit I put that fan on, it was long after it was tuned really well,

Only did it because theres no fan already, the fins are tiny, and it holds 9k all the time, and the steep slow hills really add to heat soaking.

Now it rips and on a local ride today it never got above 375 with all sorts of riding.

Re: Cpu fans


I know the fans unnecessary at the moment. and i should be worried more about tuning and correcting the problem. But it was a cheap and simple mod to do, If nothing else it will look "cool?" and certainly wont hurt anything..

Im hoping the retarted timing cools her down..

Re: Cpu fans

Well the smaller point gap / retarted timing had didn't seem to affect my temps.. the temps did seem to climb a bit slower but still hits 390 fairly quick.

Re: Cpu fans

Dominic Valentino /

You said no leaks, cool. Did you need/proceed to lap the decomp valve? The Malossi head I just installed needed to be lapped rul bad. It was machined square not chamfered to the valve i.e.:

head >| valve, instead of

head // valve

Re: Cpu fans

Positive you aren't lean? Do you have the piece of plastic/metal that covers the top of the cylinder fins the frame?

Re: Cpu fans

NEMA Victor (3 Knees Down) /

Brad Money Wrote:


> 64:1 amsoil

That's possibly your problem... I've found anymore than 80:1 with amsoil, you'll be running hot on new kits during breakin period.

Re: Cpu fans

The de-comp valve is sealed up fine. I don't use it nor is it even hooked up so there's no reason for it too leak. It also passes the starter fluid check.

I do have the plastic cap for the cylinder..

I actually filled up with this morning and mixed 80:1. No change..

Its gotta be a damn exhaust leak. I did a few plug chops and half the plug was perfectly colored. The other half was a sort of a grayish.

Re: Cpu fans

Tommy from Charlotte has cdi cases and a cdi that cant run a fan so he is using 3 cpu fans with great success. We did an easy 30 miles of 57mph and he stayed solid. For you, it's probably just a tuning problem, you shouldnt need it in addition to the regular fan. My roomie runs a pinasco kit on stock cases and hasn't had even slight heat problems, and I doubt you're running anything that nasty

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account