rcw

I have a 30 year old K&B .40 with a perry carb. The engine is in good shape, starts easily and develops good power. I do have a problem that I can't seem to fix. When advancing the throttle everything is fine until about 3/4 - 7/8 full throttle. At that point the RPM drop suddenly and drastically and the engine quits. It runs steady from idle up to about that 3/4 point. Changing plugs does not seem to make any difference. Any suggestions?

Bob Wisinski

tadawson

Sounds like the main needle may be set too lean . . . .

- Tim

rainedave

My Feedback: (1)

The O-rings in a Perry carb that old are probably like hard, brittle plastic by now. I have fixed up about a dozen old Perry's over the last several months by cleaning them and replacing the O-rings. It's easiest to simply take an X-Acto knife and cut the old ones off; you can't reuse them, anyway.

The good news is that I have found a cheap source for O-rings that are a perfect fit for Perry carbs. Harbor Freight sells a box of them and one is just right for the idle disk and another is just right for the needle valve (unless you have the old style with the spring).

There's a tiny slot in the idle disk with a hole in the center of it. It's between the two O-rings. Take a piece of paper and slide it through the slot to make sure it's not clogged. Don't enlarge the hole with a pin or anything like that. Just make sure it's not clogged.

Here're photos showing the O-ring set and the two that are perfect fits.

David

BTMH

O-rings in Harbor Freight box, is there one that can be used for the carb neck? My Perry carb is made of plastic.

rcw

David,

Thanks! I have a Harbor Freight just about a mile from me. I will stop there today and replace the O-rings.

Bob

stumblebum(2)

Hey Guys,
I just ran across your post about the perry carburetor "O" rings. I came up with a Perry to replace the Irving than is on my K & B 40 I'm putting back in the air after 26 years. I couldn't find the package in the Harbor Frieght Catalog. Do you have an Item or Part number for it?
Stumblebum(2)

stumblebum(2)

Whoops!!!
Sorry. I shoulda looked at the pictures first. I was so excited to find a cure I went off while on safety.

stumblebum(2)

Paulekins

old thread i know but it has saved me a big head ache i found similar ones on e bay
which i hope will solve my leaking Perry carb

http://www.ebay.co.uk/itm/3220795289...%3AMEBIDX%3AIT

captinjohn

Thanks for the link...0-rings are used in a lot of RC equipment !

Paulekins

no worries