Still no spark on the 303

[ksatter26]

No progress to report on the build. I've been attempting to start the Polini for over a week with no joy (spark). Battery consistently at or above 12.5 vdc. Starter turns over. Good fuel flow. Good compression. No spark on plug.

Tried isolating the system by connecting only the battery, Starter and kill switch AFTER re-wiring the starter and kill switch grounds to the engine rather than the engine mount ... I thought maybe the rubber mounts were insulating the ground. I even bought a new plug. No joy.

Contacted 4 local 2-stroke small engine shops. None would even come out to look at the problem. Most were terrified of LIABILITY problems with an airplane application.

Frustrated with the lack of Polini documentation. When I emailed the Polini Parts place where i purchased the radiator relocation parts, he tersely replied with a link to the Polini manual delivered with the engine.

At this point I'm pretty sure it is a grounding problem.

Any ideas out there?

[Badland-F5 Pilot]

So, plug out of the head, the plug grounded to the engine, hitting the starter, no spark?

The only other thing that may cause no spark is the magneto has an issue. You have the 303 is that correct?

You also may wish to join the following group if not already a member – they may be able to tell you how to test the magneto. You're spot on though, the documentation isn't that great and is difficult to find anything on this engine. I can only find the Italian version. Is your link to an English version of the documentation? If so, would you please post the link?

https://www.facebook.com/groups/2891995454368933/

Todd

[LA F2 Flyer]

Perhaps disconnect the ground wire for the kill switch for now. (If the kill switch is the same as mine, it needs to complete the ground for the engine to shut off.) I would eliminate one more point of failure. You can always kill the engine by turning off the fuel flow.

I can understand your frustration with this. I am sure the current heat wave isn't helping the situation any. Pictures and the link to the manual might help us, as Todd mentioned.

[ksatter26]

A week or more ago I had NO kill switch and had the same problem. I added the switch since then after talking with Peer. The ground side is pretty much isolated to it's own separate contact on the cylinder head. The actual switch is a SPST, 12 VDC/15A automotive toggle switch which I checked before installation.

I'm sure you guys have the Polini Thor 303 USE and MAINTENANCE MANUAL delivered with the engine ... in Italian and English. Not much help. I have a PDF if anyone is interested. The only reference is www.polinithor.com which is ONLY in Italian, but the local USA POLINI PARTS site (Ohio?) has it in English ... still no help.

[LA F2 Flyer]

Neither one of us have the Polini 303 - I actually have the Polini Thor 200, and the manual for that one isn't much better. Very poor, actually! Let me see if I can find it in your link and go from there.

[Badland-F5 Pilot]

No manual. I'm at the present going with the Hirth F-23, and hey Kurt, I don't even have a kit for my plane yet At least you can be frustrated I can't even do that! ... at least not yet!