Mystery problem

timw · 24 October 2005, 09:42

A bit of a problem with my Yamaha F225, and I wonder if anyone has any ideas.

It has been running sweetly all summer, but yesterday afternoon on the Thames, picked up a builders bag on the prop. Immeditely went into neutral and removed the bag. This is not an unusual occurrence on the Thames.

Once cleared, off again and everything fine until 2 minutes later engine died. Cranked it over and it tried to run but wouldn't.

Quite a tide running so dropped the anchor and sitting in the middle of the river tried to get it going. I squeezed the fuel bulb and noticed it wasn't very firm bit after a few squeezes felt fuel in it. Tried engine again and ran for 30 seconds and then died. Did this several times but couldn't keep it running.

Luckily a passing RNLI life boat gave me a tow back to my mooring.

After 20 minutes tidying up and putting covers on etc, I tried the engine again, and it started and ran fine. I let it run for 5 minutes, revved it and every thing is fine.

My question is could this problem be related to the debris on prop incident, or is there anything I can do to check things, as bit hesitant to go out if this problem repeats itself especially if it was to happen on a busy stretch of river.

I thinks it's fuel related...the filter was new 6 months ago.

Any ideas gratefully received.

p.s. there was plenty of petrol in the tank!

Nick Hearne · 24 October 2005, 10:14

I would replace the fuel bulb as it is cheep and as Bogi told me is a very common cause of fuel problems!
I was getting a same problem with my Opti & replaced the bulb, the old one would work only intermittently squeeze it & no suction, give it a shake & it would work again!
Also much cheaper than replacing the diaphragm in the fuel pump

but hey we live & learn

codprawn · 24 October 2005, 11:33

It may have been the engine management system having a bit of a fit trying to protect your engine - sometimes they take a while to realise the problem has gone away!!!

Searider · 24 October 2005, 11:52

Quote:

Originally Posted by Nick Hearne

I would replace the fuel bulb as it is cheep and as Bogi told me is a very common cause of fuel problems!
I was getting a same problem with my Opti & replaced the bulb, the old one would work only intermittently squeeze it & no suction, give it a shake & it would work again!
Also much cheaper than replacing the diaphragm in the fuel pump

but hey we live & learn

I would definately recommend changing the fuel bulb if yours is not a genuine Yamaha / Quicksilver one.

My boat had a "Tempo" fuel bulb fitted and I've had numerous random shut downs. Apparently the Tempo bulbs, whilst looking good have a tendency for the shuttle valves to jam. - Runs ok now that a Quicksilver one is fitted

Nick Hearne · 24 October 2005, 11:54

Quote:

Originally Posted by Searider

I would definately recommend changing the fuel bulb if yours is not a genuine Yamaha / Quicksilver one.

My boat had a "Tempo" fuel bulb fitted and I've had numerous random shut downs. Apparently the Tempo bulbs, whilst looking good have a tendency for the shuttle valves to jam. - Runs ok now that a Quicksilver one is fitted

Good job I replaced the Tempo with a Quicksilver one then

timw · 24 October 2005, 14:40

Thanks for the comments,

It's due for a service so I've booked it in. They concur that it could be the bulb, but lots of other things too.

Apparantly they will plug in a laptop and a full story will appear!

Searider · 24 October 2005, 17:25

Quote:

Originally Posted by timw

Thanks for the comments,

It's due for a service so I've booked it in. They concur that it could be the bulb, but lots of other things too.

Apparantly they will plug in a laptop and a full story will appear!

Laptops aren't all they're cracked up to be. When I first was trying to find the cause of my cutting out I took the boat to my friendly Mariner dealer. He plugged in his Laptop (DDT actually) and noted that I had had 20 "almost" overheats - ie a bit "warm" but not enough to sound the alarm.
He spent all morning sorting out the overheats assuming that this had something to do with the cutting out. Took the boat away and problem still there

The cutting out got worse until the engine would not run at all. It was at this stage that the problem was discovered - there was no fuel in the engine but the bulb was solid.

New bulb for £7

Cheapest ever outboard motor bill

Soupy · 25 October 2005, 21:52

Have had more than my share of fuel problems (water in fuel/tank and engine of course) this year. Now all resolved - pleased to say. However, when working on tank or putting seperator filters in etc - always had to draw fuel back up to bulb due to lots of air blocks and resulting in old petrol siphoning methods (i.e. a petrol mouth)! So how do U replace a bulb without introducing air?

Pete7 · 25 October 2005, 22:16

Squeeze bulb, place thumb over open end of fuel hose, release bulb, release thumb, fuel starts moving up fuel line,continue and repeat. Replace engine connector when fuel appears at end of line.

Pete

Rogue Wave · 26 October 2005, 00:22

Would that be a mark one thumb or the new type?

Pete7 · 26 October 2005, 08:39

Mk1, thick stubby type are normally the best.

Cookee · 26 October 2005, 09:17

Every fuel bulb I've ever come across will pump air and fuel - never had to use my thumb!

DJL · 26 October 2005, 13:19

Quote:

Originally Posted by Cookee

Every fuel bulb I've ever come across will pump air and fuel - never had to use my thumb!

I agree.

I use one regularly (or not so regularly as the neighbours might say) to pump fuel from the boat into the lawnmower. That always pumps air and self primes.

Hensh · 26 October 2005, 19:04

Quote:

Originally Posted by DJL

I agree.

I use one regularly (or not so regularly as the neighbours might say) to pump fuel from the boat into the lawnmower. That always pumps air and self primes.

Priming bulbs will suck air and there is no need for bleeding the system on carb models as the carb float chambers will do that for you. Even the the injection engines are self perging.

timw · 04 November 2005, 13:07

Many thanks for your replies...but the mystery deepens.

Despite the engine being able to idle, underload it cuts out.

However, on linking the engine up to a portable tank, it runs fine.

We have changed the bulb as well.

So the problem appears to be that the engine is unable to draw fuel from the main tank.

I guess this may be something to do with fuel lines / breathers. Everything visible looks OK, but there is no inspection hatch to look at the tank

I suppose we will have to cut a hole and make a hatch to have a look at it.

jwalker · 04 November 2005, 14:00

Does the fuel come up the pipe to the engine easily? If not, work down the piping, opening it at each connection, and try again. If you find that the blockage is in the tank section and you are unable to suck it clear, then blow it back into the tank. It could be that it will never recur.... then again, it may.

However, it's a bit less drastic than attacking the floor and opening the tank.

jyasaki · 26 November 2005, 07:21

Quote:

Originally Posted by timw

Despite the engine being able to idle, underload it cuts out.

However, on linking the engine up to a portable tank, it runs fine.

Sounds like it *could* be the fuel pump in the engine (unlikely, though, if it runs fine on the portable.)

One thing to try is to leave the filler cap open a bit to bypass your breather tube.

Does the fuel bulb on the primary system collapse when you're running? If so, it points more to fuel line clog.

Oh, and you might want to change out the filters again (I'm assuming you've got a cannister type filter in-line somewhere.) The on-engine fuel filter should be relatively cheap.

Luck;

jky