Any Mikuni Users/Experts out there ?

[nipper]

 

Thanks for that Nipper, you'd o thought he'd have it all in hand.......well he has but engineer is booked for next weekend to service the boat.....I'll have to make sure there is a fuel filter ready for him.

Thats good!

 

 

Quite a lot of boats that come out of boat yards, having been bought by proud new owners and then have engine problems, all due to old fuel, blocked filters and the bug.

 

It always pays to check and replace all filters and then inspect those old filters for grud and the bug!

 

Happy days!

 

Nipper

[nb Innisfree]

No such thing as a 24v plug, the unit has a resistor and uses the standard plug so easy to get from Mikuni or a Beru equivelant from other sources.

 

For the OP, there I've just remembered there are no flash codes for either of the 60s so it will be old school diagnosis, start with the fuel as that's the easiest.

Agree about the plug but our 24v MX60 has a flash code.

[nb Innisfree]

There are actually two distinct model of MX60 not just a 12v & 24v model, the overheat reset button would not help the OPs symptoms as his is trying to start, with an OH trip that would not happen.

When I investigated parts for our 24v MX60 I could only find two models, one 12v the other 24v, both mechanically identical except for the glowplug resistor on the 24v, but the older 12v model was much simpler electrically, the 24v one had a control box that Miluni states is same as MX40. In fact the circuit board on ours is printed with MX60/MY16(?) and possibly MX40 though I can't remember that bit. Tried everything to cure smoking and coking including trying Mikunis control box they use for testing, nothing worked but it was cured when ULSD became available.

[NMEA]

When I investigated parts for our 24v MX60 I could only find two models, one 12v the other 24v,

I can send you the parts lists for the type one and type 2 MY60 if you like, I assure you there are two, four if you include 12v & 24v

Finally managed to get the picture sorted....

 

Here is the unit, have traced all wiring and I haven't found a control/led unit.

OK, stop looking for the control module, you will not find one.

[nb Innisfree]

I can send you the parts lists for the type one and type 2 MY60 if you like, I assure you there are two, four if you include 12v & 24v

Fair enough, I'm not disputing that (I assume you mean MX60 rather than MY60?) My bit of research was 12 years ago so I'm probably way behind things, or maybe I'm more incompetent than I thought! Whatever it seems my original post is wrong and I'm not qualified to contribute so I think it best to keep quiet on the subject!

[NMEA]

I wouldn't think that for a moment, it wouldn't be the first time a customer had made suggestion to me that proved useful.

[Blazeaway]

I have ordered a new glow plug (and a complete gasket set too as a precautionary/spares item)

 

I will go and get a diesel fill up in case its fuel starvation, and test the fuel line as suggested to see if any is getting to the unit. I will also fit the new glow plug.

 

Its odd I can't find a control unit though, what on earth is controlling the sequenced start up ?

[NMEA]

Its odd I can't find a control unit though, what on earth is controlling the sequenced start up ?

I your case a few primitive bits and pieces under the black cover in top, but not a control unit in the acccepted sense.

[Blazeaway]

I your case a few primitive bits and pieces under the black cover in top, but not a control unit in the acccepted sense.

 

OK cheers, I'll go back to simple diagnostics, check fuel and ignition first see if that throws up anything.

[Blazeaway]

The parts arrived today, so went and fitted the new glow-plug and tried again.

 

Same problem as before, so checked diesel flow which was poor, appeared to be a lot of air bubbles.

 

Bought 30 litres of diesel and dropped that in the tank and then we had good diesel flow at the pump.

 

Tried another start-up still no good.

 

Removed the wires from the new glow plug and connected them to the old one and earthed it so we could see if the glow plug was heating, result was it was stone cold.

 

Onto the control panel.......RESULT Found the control box hidden under a pile of wires, and found 2 blown fuses. Replaced them both and tried again RESULT Mukuni fired up and we had hot water in the supply pipe.

 

However: still got a small problem, there was a phenominal amount of smoke which I thought would burn of, but even after 20 minutes its still really smokey, it wasn't on the survey last week. So something has changed and not sure what.

[NMEA]

However: still got a small problem, there was a phenominal amount of smoke which I thought would burn of, but even after 20 minutes its still really smokey, it wasn't on the survey last week. So something has changed and not sure what.

Numerous failed start attempts = puddles of diesel in the heat exchanger and exhaust, this can produce loads of smoke, I have known it take a couple of hours to clear so be patient for a while and keep it running hard. The carbon coating on the heat exchanger walls also gets coated and absorbs the diesel, but that tends co clear much faster.

Edited February 3, 2015 by NMEA

[Blazeaway]

Thats fanastic hands on experience, I will give it a good hard run for a few hours.

[Blazeaway]

RESULT !!!

 

With the help of you guys, especially NMEA as I got into the fine detail the Mikuni lives another day.

 

Ran the unit for 2 hours today, all smoke gone and all rads on full blast got the boat to a toast 28 centrigrade, bit too hot really.

 

Looks like the main cause was 2 blown fuses, not sure what they were protecting though. Probably caused by really badly crimped cables at the connection to the top mounted module. What didn't help was that the main diesel tank was almost empty and I didn't know that, so also fuel starvation.

 

 

THANK YOU EVERYONE FOR YOUR INVALUABLE HELP AND SUPPORT.