MacGregorSailors.com

Hi I am new to the site, so welcome any feed back.
I have a 2005 Tohatsu 50hp oil injected 2 stoke outboard and just recently between 3000 and 4000 revs it seems to be missing, it sound like a fuel blockage but then it goes away again for a while and then mysteriously returns. When it is missing I open it right up and it seems to clear its self, but this has happened on my last three outings. I took the plugs out and cleaned them, thet did look a bit oily, not sure if this is correct or no. On tick over it is absolutly fine and she starts first time, I have changed the fuel filter so it cant be that. p.s. I am not the best at anything mechanical so please speak in my language!!
Yours Bob.
p.s. plug type i was informed to get was NGK BR8HS-10 is this the correct plug please?

hi
these engines suffer from a couple of issues that coud give you the mentioned headache. I have had something a little similar.
Make sure your tank inlet valves are open! Obvious, but I think we've all been there.
These lumps have a rather stretched fuel pump capacity. Any leaks in the fuel line can cause problems, Also, the diaphram of the actual pump is something that could do with being kept fresh. Stiffening or splits here will again cause problems.
I've just changed these items, though won't be able to test it for a while
Then we'll be in the Aegean for about 2 months cruising....
you can download a manual from my site. Otherwise, these are very robust lumps.

Hi thanks for your reply, I have heard that pin holes in the fuel line can cause this problem. As the engine is 6 years old and on the original boat I doubt the line has been changed, I will renew this first. Thanks again.

you could pressure test it.. unless it's been left ou tin the sun it may not be the culprit. the motor end is auto sealing, so i fyou can stuff a couple of bar into the tank end with the empty hose underwater you should see soon enough if it's misbehaving. In fact that's such a goo idea I'll be doing the same with mine tomrow!
I do try to make sure I'm through the cash at the right areas... a coule of fuel lines & primer bulbs can purchase much niser bits of kit
good luck!

Ok thanks, but for what it costs i think I''ll just buy a new fuel line and some new plugs and try that first. As I said sometimes its as sweet as a nut all day and then it plays up for a while. But touch wood not completely let me down.
Cheers.

are you uk or us based?

My E-tec was doing similar things-replaced the primer bulb and problem solved.

Bob

Also check thosde pesky quick connect fittings. the O ring goes bad after a while and leaks air into the fuel line

Ok thanks for the last three inputs, better go shopping for fuel line, spark plugs, primer bulb and those pesky Quick connect fittings
Im UK based, Cornwall

p.s. note to bscot who sent messagw about the E-Tech primer bulb. I take it that 'HUFF AND PUFF' is your boats name? What a brilliant name, like it and thanks for reply i will be trying that today.
bob

Cornwall.. great place for a Mac!
Are you a member of the super mac owners assoc? if not why not?

Cornwall? I keep my M on the Tamar - Cornish side of course . Where do you sail from Bob?

Paul

kitkat... you've been rumbled... jacobs' ladder on the back of your boat?

bob the builder wrote:p.s. note to bscot who sent messagw about the E-Tech primer bulb. I take it that 'HUFF AND PUFF' is your boats name? What a brilliant name, like it and thanks for reply i will be trying that today.
bob

That's her name--hope your running issues are fixed--let us know the outcome

Bob

Hi, reply to all that helped. I have changed all the fuel lines, primer bulb, fuel tank connectors, fitted a Delphi fuel filter and new spark plugs. Noticed that a couple of the rubber washers in the connectors were a bit dry and cracked and the chap in the chandlery said that this could be letting in air. Anyway she seems to be going well at the moment but not took her out under load yet, hopefully this has sorted it and I'll let you all know after her next outing.
Thanks again yours Bob.