8 hp Yanmar (81CD27)cuts out mid throtle after new pump and

[Paul Kamins]

I have a friend who is a mechanic and he tried to fix his fathers new boats problem by changing the fuel filters(which were clean), the fuel pump and it still cuts out and stops mid throttle. It will idle all day. If if cuts out mid throttle, if will start right back up. He is thinking there might be an occult flapping area in one of the hoses, but I told him I would see if anyone else has any other suggestions. Thanks, Paul.

[David van den Burgh]

Could it be that the fuel pickup in the tank has a screen (or something similar) - like Cape Dorys - that is getting blocked up? Once the engine dies and suction ceases the gunk falls to the bottom of the tank, allowing the engine to start again and operate normally at idle until the throttle is cranked up and gunk again starves the engine of fuel.

Just a thought.

David

[Dave Disbennett]

We had a similar problem on a new boat . It wouuld run fine and then randomly die as if starved for fuel. Iturned out Yanmar came up with a new air intake system and the hose that drew air into the intake would suck itself onto a wiring harness, theengine would die the hose would let loose and the thing would start and run normally. This wa all figured out after several hours of sea trials and tearing the fuel system apart.

It is also possible that a fuel hose is delaminated and collapsing internally. I've seen that more than twice.

Good Luck

Dave

[M. R. Bober]

I'm going with Dave, the younger. On TIA MARI (CD27' 1979), I spent an exciting afternoon head down in the port cockpit locker after the engine quit. It stopped for no reason (fortunately I was in a safe location.) After a few minutes, the engine would restart--normally--but quit again as the engine speed was increased.

I removed the standpipe from the fuel tank (be carefull when replacing it as it is easy to cross thread into the aluminium tank fitting,) and found a black tarlike snake of goo in the pipe. There is a small piece of stainless steel screen in the 90degree fitting on top of the standpipe. It traps goo. It is a known cause of trouble. Consider removing the screen. The filters downstream will catch any debris that the screen would have.

Mitchell Bober
Sunny Annapolis (which is not the home of the GooGoo Cluster) MD

[Bob Miller]

You also might want to check to see if the fuel tank air vent is ok. When I first bought my CD 27, it would run for a while and then die. It turns out that saltwater splashed up on the fuel vent fitting (located on the transom) and got all crusty and no air was going into the tank...then I would not be able to pump fuel out at speed, but idle was ok...just a thought.

- Bob Miller
"Good Times" CD 27