What kind of screws are there on a Enya .35 head and crankcase. I have to replace them.
First I assumed it was metric like M3 or M4 but now I am not so sure.

Hey KKj,

To determine screw threads you need a thread pitch gauge, a good vernier caliper/micrometer and a reference chart.
I don't own an Enya, but being Japanese I think it's safe to say the threads are metric. You can use your drill index box to determine the diameter of the screw.
ie: 4mm= .157"=5/32. A 4mm screw should just fit in the 5/32" drill slot.
3mm=.118". it should pass through the 1/8" slot, but not the 7/64". This diameter is getting close to a #4 at .112" so this where a pitch gauge and vernier come in handy.

I'm certain your screws are a Metric Pitch, but I hope someone with an Enya can confirm this. Standard Metric course pitch is as follows:

M3 x .50 mm x length
M3.5 x.60 mm x l
M4 x .70 mm x l

I'm going to take a shot in the dark here M3 x .5mm x 12mm is what your after?

Happy Fly'n....

The ENYA head and front cover screws are metric. They are 3MM but they are not the same pitch as the OS screws(40FP). I know that they ARE the same as the older OS 35-S screws. I have used ENYA screws for the rear cover on the 30-S and 35-S engines. I could send you a set of screws AIRMAIL, but I need to check the postage with my PO.

Regards, Duane

[email protected]

Chances are they're a Metric fine pitch then. Try M3 x .35mm x length.

Happy Fly'n....

Thanks, but it is not that easy.
There are different screws to the head and front cover
The head screws are 2.85 mm. (and not possibly 7/64)
An M3 does not fit
The front cover are 3.4 mm (3.5mm?) Not possibly 9/64
I haven't tried with a M 3.5 because I haven't any yet.

If I had a thread pitch gauge I would have the answer.
I take my screws and go to the bolt and nut store!!

Hey KKj,

Your on the right track. The screws will be Nominal Metric size. 2.85mm is probably the right size for M3. a.15mm difference is only .005"/inch. 3.4mm is about the nominal size for M3.5

It's just a matter of determining the pitch? MECHANIC stated in his post that the O.S. screws were not interchangeable, so it leads me to believe they are a fine pitch thread.

Can you compare the thread of the M3 screw to a 4-40 bolt? Put one on top of the other and hold it up to a light. If it looks like the M3 has twice as many threads on it, chances are it will be a M3 x .35mm (fine pitch).
I calculated that the .35mm pitch works out to about 72 TPI (threads per inch). Almost twice that as a 4-40 (40 TPI). These will be bolts that may not be available at any corner store, mind you, your in Europe and it's a metric world over there. Good Luck.

Happy Fly'n....

Call Altech Marketing in New Jersey. They are the Enya importers and have a listing of all screw sizes.

You don't have a phone number?............they are not on internet?....

Actually you can go to the manufacturers question section here under the engine forum look for Enya. Jeff Green has the number at leat 10 times in the posts.

Hej!
Minicars i Uppsala säljer Enya motorer!
Där hittar du också 3,5mm insexbultar i olika längder(från Du-Bro).

Hälsningar!
Jan K
Väsby MF

OK, det är fortfarande oklart vilka gängor det är. Alla gissar men få vet.