limd

Hi I have a YS 61R bench mounted for running in. I am currently running a 12.5 x 8 prop and 20% castor . The engine is fitted with a tuned pipe.

I can only start the engine when I prime the carby. The needle valve is 2.5 times open . The engine fires up then stops. The throttle setting is on idle with full trim "on" . When I advance the throttle SLOWLY the engine dies. I have tried the needle valve in a variety of settings with no luck. The plug is an OS no8.

Any help would be appreciated. Thanks

Dave

Dave Shadel

First of all, is the tank building pressure? If it is, the regulator obviously is not passing fuel.
The needle setting is very rich at 2.5 turns, but the engine should operate there. Normal setting is about 1.5 turns open.
If the engine has been stored for a long time the regulator needs to be disassembled and cleaned.
It is also possible that the gaskets have swelled and are blocking the fuel passages between the regulator and carb.
Let me know what you find.
Dave

limd

Dave,thanks for your reply. Tried turning the needle in to 1.5 turns. The engine started with priming but died again (as soon as the primed fuel in the carby runs out).

I took all the pipes one by one of the engine and blew through them. The front nipple on the engine where the instructions say to connect the fuel clunk too was impossible to blow air into. This leads me to suspect that something is blocked as you indicated could be the problem. I then tried to suck from the rear nipple which is supposed to blow back into the fuel tank. That was no good either.

What would be my next step?

Grateful for your help

Dave.

Dave Shadel

Blowing and sucking on the fittings is a complete waste of time and won't tell you a thing as you are only working on either side of the regulator. They will always be plugged. The problem is BETWEEN the regulator and carb most likely as there are passages in the crankcase which allow fuel to go between them. There is also a pressure hole from inside the case to drive the diaphragm. Everything needs to be taken apart and you must make sure that all the passages are open.
You did not answer my question about tank pressure. Is the tank pressured up and is the check valve working correctly.

Dave

limd

Dave,

Problem solved. The tank wasn't building pressure. Fixed that and have just spent the last hour running a couple of tanks through the engine. Thanks for your help

What would you recommend for a fuel mixture ?. Here in Adelaide its far cheaper to mix your own.

Once again many thanks
Dave

STEVE LENZ

My Feedback: (45)

Dave i have new 61 L It will not idle after three tanks of fuel. when i give it throttle it spits small amounts of gas out of the carb and die's. The tank has lots of pressure, turned lower regulator screw just about all the way in did not make a difference.props were 11-8 and 12-6 I am new on line here so bare with me if i have this listed in the wrong forum

Dave Shadel

What is a 61L? YS has never made one of these to my knowledge.
You may have damaged the regulator by turning the screw all the way in. Your problem sounds like a leaking regulator plunger, but we cannot tell without seeing the engine.
You might be better to send it in to us for an inspection. The service dept. address is:

YS Service
1295-C Industrial Court
Gardnerville, NV 89410

Phone:775-782-4562

Thank You,
Dave