Mukiwa

Hi Geoff. It could be you are right. Before they did any work they indicated the cost would be £200/300 but in the event it came to £120. So maybe they did not do much? I have been told about an injector pump specialist who is based near the Macc and as we will be up there in August I might try him. I'll keep you posted on any developments. Thanks for all the thought you have given to this. Mike

Hi Geoff. I didn't mention it but the symptoms are the same with and without the throttle cable connected. Thanks Tony. I will leave it to others as I don't know enough to understand.

Hi Geoff. I have been trying what you suggested but ended up being very confused. I will try to explain. It may help if I explain two terms I use. Low idle: when the engine is cold, when it is in gear at any temperature, if I stop the engine and start again. High idle: when the engine is hot and out of gear. With the low idle adjusted to 950 rpm the high idle is 1250. I adjusted the low idle in stages up to 1100 rpm and the high idle is always 1250. If I try and reduce the high idle nothing happens until I put it in gear and then I experience take up stall if the low idle is below 950 rpm. I'm sorry if the explanation is confusing but I don't really know how to explain it in any other way.

Thanks Geoff. I'll try that tomorrow when I finish cruising. Mike

An update. Three springs have been replaced in the governor. The slight variation in revs at cruising speed has been cured but the basic problem of revs at idle still persists. When the engine is cold or freshly started it will idle at 950 rpm. As soon as it is warm it will not drop below 1250 rpm. I guess I will have to live with it as I'm not prepared to spend any more money on this engine.

A small ball bearing in the bottom of the cup and liberal application of grease may give you what you are looking for.

Thank you Geoff I'll ask the reconditioner about that. Hi Bizzard we did try running with the fuel cap off but it made no difference. Thanks for the idea though.

I don't know Richard. I'll ask the question although at the back of mind I seem to recall someone mentioning that they are sealed units on this engine. Mike

A few hundred pound later, a reconditioned injector pump fitted, new fuel pipes, governor checked and lift pump removed and I am back where I started. The engineers are tearing there hair out. They have been in touch with Kubota and they can offer no further suggestions. As you can imagine I am extremely frustrated and to make matters worse it is now beginning to vary it's revs at cruising speed (1600). Not by much but within a range of 100 rpm. It's difficult to know where to turn next.

Thanks for all the suggestions. It is not caused by the cabling as when this was disconnected the problem still occurred. I like the idea about the filter in the lift pump. A couple of years ago I did have dirty fuel and when it was cleaned a lot of grunge came out. I will try that before I go any further. I get the impression that if needs be it would make sense to have the injector pump reconditioned rather than buy a new one.

Hi Geoff. The problem first became apparent a couple of years ago and over time has become steadily worse. It only happens at lower revs ie idle can vary between 950 and 1250 revs. Another symptom is that is does not increase speed smoothly. All the symptoms are worse when the engine is up to full operating temperature.

It's a Nanni 3 cylinder, 29 hp engine with Hurth gearbox ZF 100.

I have been having problems with wildly varying idle speeds. An engineer came out yesterday and diagnosed a sticking rack in the injector pump. I have no idea what that might be. He recommends having the pump reconditioned which will cost about £200/£300. Is this better than sourcing a new one?

I think Phil deserves a mention. He has sign written two boats for us and both times he has exceeded our expectations. As well as his sign writing, his work on cans, dippers, back doors and cabins is excellent. I cannot recommend him highly enough.

And few places more awkward than Dadford's Wharf!

Ah but the have a very interesting rugby football museum as befits the birthplace of the game.

Thanks Cotswaldsman..

Next weekend we are planning to head down the Severn to Gloucester. We want to spend sometime exploring the city. Nowhere can we find any information about how long we can stay in the docks. Does anyone have any idea? T hanks Mike

Thank you for that informative answer. It is most helpful in making a decision about propeller size.

.If I cruise at 3 mph at 1400 rpm, will my fuel consumption improve if I change the pitch of the prop to cruise at 3 mph at 1800 rpm? I assume the same hp will be required as I am moving the same weight at the same speed.

I added a 50 gallon auxillary tank some years ago on Sarah Kate. it was connected to the main tank and had a balancing pipe. Filling took place at the main tank and the take off was also on the main tank. the main effect I noticed that it was slow to fill the last few gallons as the air was not able to escape easily. There was no discernable difference to trim or boat handling. The tank was placed so that the weight was evenly distributed from port to starboard and it had internal baffles to diminish the effect of "sloshing". Hope this helps.

I think Craftmaster have changed the formula. The last bottle I bought was not that good. I still had some in an old bottle so I was able to compare and I'm convinced it has changed for the worse.