Craig F

Can anyone tell, or better yet show me where to put the tap on a Ryobi crankcase? I
want to tap it for smoke but I want to drill it in the right place. Also should the engine
be disassembled for this? I wonder if any debri that gets in there will just blow out the
exaust. Thanks for any help....Craig

andrew66

i would definately take the engine apart before doing any drilling. the filings will get into the rod bearing, and the main bearings in the case.

davewallace

My Feedback: (29)

Craig,
I took a look at one of my Ryobi's that is still tore down ,because of no oil. The cylinder is held on with two screws. If you remove the cylinder, leaving the piston attached to the case, you will see the mounting flange at the bottom. You can drill and tap the back of the flange, about 3/4th inch in from the end. There is a lot of meat here and the hole will go directly into the transfer port. Use a 8-32 tap or one that matches you fitting. A DuBro pressure tap fitting would with a 8-32 thread. You can do it on either side and you won't have to disassemble the mount,carb etc. After drilling,tapping and installing the fitting with gasket or sealant, clean the filings and oil the bore. With the piston at the top of the stroke,align the ring gap with the pin in the ring grouve. Insure that the gasket or sealant is in place on the top of the case flange. Compress the ring and slip the piston into the cylinder. Seat the cylinder and install the two retaining screws.

Dave

Craig F

andrew66, I thought about that as I was typing!! Davewallace, thank you, that's the kind of info
I needed. Craig

av8tor1977

My Feedback: (6)

Gotta ask... Are we talking about tapping for a pressure pulse for a pulse pump like the B & B unit, or are we talking about where to tap the muffler where the smoke oil goes in????

AV8TOR

Craig F

pressure pulse to push oil out of the tank into the muffler.....Craig

av8tor1977

My Feedback: (6)

Not really the best way to go, but it's the cheapest. Be sure to add a one way valve in the pressure pulse line, and another in the line going to the muffler.

AV8TOR

Craig F

Besides the possible leak from a blown off hose, what else is the down side?

av8tor1977

My Feedback: (6)

Just seems to be problematic, and you may not get enough flow either. Give it a try and let us know. Be sure your tank and lines don't leak under pressure.

AV8TOR

ROOSTERLEW

Do I understand this right, you are using crancase pressure instead of an oil pump?

Craig F

I have done it in the past with great results, even on a 40 2stroke!!! I flare the copper lines a little where the hose attaches
and wrap wire around to help hold it on. As far as not enough oil, I had to put a resricter valve ( is that spelled right?) on
the Toro to slow it down a little, workes GREAT !! used a du-bro # 225 valve. On the 2 stroke people said it wouldn't work
because of even pressure but I did it anyway and it worked great. I put a nipple on the muffler where the one was for
the fuel pressure and the other REAL close to where the exaust enters the muffler,(most heat) and it worked fine. Everyone
at the field wanted to see the inside of the plane cause they never saw a forty size 2stroke smoke. I sold that plane and now wish I didn't.