Help Possible Fuel Starvation tank switch

Dero · 10 October 2015, 19:45

Can anyone advise the best method of switching between tanks. I have an ongoing an issue with fuel starvation at full revs and we think it could be the brass switch valve maybe smaller diameter than the fuel line which maybe causing fuel starvation at high revs. We are going through the causes and this is the only thing we haven't tried. A trusted friend has said that this is a common problem to the extent that he has removed the switches on all of their rescue boats.

Just wondering if anyone has had the same problem and what is the common method of switchover of tanks,

I have a 80 hp fuel injected 2 stroke with 2 23 litre tanks?

Any ideas would very much appreciated

willk · 10 October 2015, 20:52

Have you changed your fuel filter recently?

I used to run 90hp Etecs through those brass taps - never had an issue with fuel starvation - anything but!

willk · 10 October 2015, 20:55

OK - when you say you've tried everything - have you actually tried running the engine straight from a tank with no tap, filter, etc? A small kink somewhere could cause it, so could a damaged/blocked pickup. Or a faulty breather. There's a myriad of possibilities. I'd cut out everything and build up the system bit by bit until it calves - then you have it!

Dero · 10 October 2015, 21:03

Thats the next step running one tank with a new first line water separator filter.

This my first rib so i am on a steep learning curve. We have already installed a electric pump (replacing the bulb) although the engine seems to sound sweeter I still have the cut out at high revs which i discovered today. We have checked the fuel lines for air etc previously. Getting frustrated but i appreciate your help and advice

willk · 10 October 2015, 21:07

What revs does it cut out at? Could it be a limiter?

willk · 10 October 2015, 21:08

Quote:

Originally Posted by Dero

Thats the next step running one tank with a new first line water separator filter.

I'd suggest no filter initially (just make sure tank is clean). There should be a filter in the engine to deal with a few small particles of dirt)

Dero · 10 October 2015, 21:13

4800 revs I will get back on the water next week and try again thanks a lot!

willk · 10 October 2015, 21:21

Quote:

Originally Posted by Dero

4800 revs I will get back on the water next week and try again thanks a lot!

Not a limiter so. Thinking more - I'd swap out the engine filter too - just in case that is stuffed. Something is choking supply - just a matter of pinpointing what. I got caught out by a dirty filter not so long ago - so I tend to think that direction. It could be anything...

Daniel · 10 October 2015, 21:33

My big opti was suffering fuel starvation at WOT and I quickly traced it to a replacement primer bulb.

When replaced (again) with a genuine mercury one voila - no problem.

As it was only at 80%+ throttle (50lph or more approx) I wouldn't suggest this likely in your case. But thought I'd add it into the discussion.

Dero · 21 October 2015, 21:15

thanks all for your thoughts and advice

jeffstevens763@g · 22 October 2015, 07:22

i had a 90 Suzuki 70lt main tank two 25lt reserves quarter turn valve 1/4 inch bore [yellow on the fuel separator] on the 70lt line with a remote lead switchable between the two reserve tanks going into a fuel water separator with no issues primer bulb on each line. primer bulbs fail as does fuel lines, breather holes block,filters,hole in fuel pump diaphragm.