Before I start to strip the fuel system...

[Hightower]

....I'd like to ask opinions about my soft primer bulb and fuel delivery.

Some of you will be aware that a few weeks ago that on a jouney down Wooten Creek the engine coughed and spluttered to a stop. After a few initial checks and a prime on the Bulb I managed to get the outboard started and continued on my trip.

Altho not conclusive I suspeced the primer bulb/fuel system.

The last few cruises I have been monitoring how hard the primer bulb feels after each stop and everytime I tried the bulb is soft.

Yesterday I primed at the begining of the trip only and after about 6 restarts during the trip (drifting for fish) I had the same symptoms as before (splutter and stop). The Bulb was soft as before and after priming the engine started fine.

I have the bulb between the tank and filter/seperator, should I try to move this to beween the filter and engine, the bulb primes fine so I think this is OK. The only other resons for air getting into the system is either from the pickup pipe bottom (which I doubt) or one of the pipe conections leaking air into the system whilst under vaccum when the engine is drawing fuel.

Any suggestions?

[Nasher]

Andy

Sorry to hear you are having problems again.

It may be of no help at all, but:-
I hardly ever touch my primer bulb, and each time I have its always been soft, some engines just don't need it, so I'd check to see if your Rude needs it before stripping it all down.

I'd start by checking any fuel filter under the cowl.

Nasher.

[m chappelow]

how about the air bleed screw on the tank not fully open or vibrates closed slightly,or how about the non return valve on the bulb sticking open ,other than that apart from what you have done checking fuel line connecters and what nasher said about the fuel filter it could be a small hole in the fuel pump diaphram or badly worn one ,suppose you could try a piece of clear piping between the bulb or carb or fuel pump and get a large syringe or blow or suck with something and see if any air bubbles appear .

[Nos4r2]

Might be worth checking the fuel hose where it joins the connector. I've had the inner of the double thickness hose crack and let air in which stopped the engine before. It wasn't visible til I removed the connector from the hose.

[m chappelow]

could be an 0 ring thats worn in the fuel connecter or if its had some heavy usage the brass pin could be worn .if it has one .is there any really tight bends on the fuel pipe on the engine side ie filter ,pump ,carb as after a while the metel pipe ends may have cut through the rubber or not fit right and thats weeping air in ,

[Hightower]

Thanks for your replys.

I pumped the bulb hard before flushing my engine today, started the engine and observed the bulb, sure enough after a couple of mins the bulb went soft again. At this stage the bulb was above the fuel filter and any hose bends so I can only assumm that either air is entering the fuel hose where it connects to the fuel tank and rising into the bulb or is entering some other part of the fuel system (filter being the a likely suspect).

There is no smell of petrol anywhere on my boat

[PeterR]

Hi Do you have an inboard tank or external 25ltr ones .for the 150 you require large bore fuel hose from memory 3/8 if you havent you ru n the risk of fuel starvation and its asociated problems.Fuel filter as already suggested is a must.And for the cost definately the bulb only last month it was the cause of almost identical symptoms on a 90hp 2 stroke although carb mariner.check you are using the corect 2 stroke oil.I,ll think about it more and if i think of anything else will post

[Hightower]

It is an inboard fully vented tank and all installations for the outboard is correct.

[Nasher]

Originally Posted by Hightower

Thanks for your replys.

I pumped the bulb hard before flushing my engine today, started the engine and observed the bulb, sure enough after a couple of mins the bulb went soft again.

Should the Bulb really be hard whilst the engine is running?

I thought it was only supposed to be hard before starting.
To be hard during running there would need to be pressure in the line.
Or have I got it all wrong?

Nasher.

[Hightower]

Originally Posted by Nasher

Should the Bulb really be hard whilst the engine is running?

I thought it was only supposed to be hard before starting.
To be hard during running there would need to be pressure in the line.
Or have I got it all wrong?

Nasher.

My Oil priming bulb is rock-ard. By my reconing if there is no air in the system then why would the primer bulb be soft?