DaveyMo

How Do:

Perhaps an accomplished "Norvel-Head" give me a hand here. I'm trying to remove this engine's cylinder to check out the wrist pin. The four socket screws are not cooperating. I've tried the 1.5 mm hex and the 1/16" hex - neither is a good fit. The 1.5 mm wants to round out the socket, while the 1/16" won't fit in at all. I've measured both hex stocks and they measure 1.48 mm and 1.57 mm respectively. Could these socket screws require some kind of odd-ball size hex stock, or is the odd ball on this end of the keyboard?

Davey Mo

combatpigg

My Feedback: (3)

Davey....my 1/16" hex driver fits the screw heads pretty good and so does a 1.5 mm.
If you are having trouble with the 1/16", try grinding it back to virgin metal and hammering it down onto the screw head.
If the screws don't wnt to budge, you aren't using enough heat yet...!

Andrew

The correct size is 1.5mm. The problem many times is the allen wrench itself. Since almost all the tools we are able to get today are Chinese, they may either be mis-shapen or soft and eventually lead to rounding off. If your engine has some run time on it or has been run then allowed to sit, you may have some luck applying heat.Try to heat only the flange the screw passes thru. Adding a little penetrating oil, heating, then giving it a day or so to soak in also helps; reheat to extract..

I replace all the cylinder screws with M2 x 8 black oxide socket heads --- the length lets the screw extend below the case flange. If you ever snap a screw off, you can usually grab the screw below the flange with some needle nose and back it out. If it snaps off flush, it is almost impossible to remove.

EDIT: CP jumped in while I was typing, but his advice is the same: Heat is your friend!!!

Pond Skipper

Can anyone confirm .074 uses 2mm? I dont like the flat heads.

Andrew

PS -
I'll check tonight when I get home from work.
andrew

Pond Skipper

Looks like 2.5M x 8M

I checked the manual no info on screw size.
My caliber reads 2.44mm dia. x 7.5mm worth of threads.
I dare not fire this one up till the threads are oiled at a min.

DaveyMo

Combat-porker and Andrew:

Thanks for the good advice. I'll give it a go in the next day or two. And Andrew yes, I intend to replace the existing screws with the longer ones as you suggest. In fact, the replacement socket heads fit the 1.5 mm hex wrench perfectly.

Dave...

Andrew

PS -

I just checked on the .074 cylinder screws. The size is 2.5mm. As with DavyMo, I would choose a length that will allow the screw to extend below the case flange. I have both 2.5mm and 2.6mm screws in stock and also tried the 2.6mm --- it was too large.

andrew

Pond Skipper

Yes agreed thank you Andrew for the double check with the 2.6mm!!

I will order a set:

Du-Bro 2118 2.5 mm x 10mm Socket Head Cap Screw