Any Mikuni Users/Experts out there ?

[Blazeaway]

Had my new boat 24 hours now and hit my first problem.

 

On the survey, a week ago, the surveyor ran the Mikuni heater for about an hour, no problems at all rads got really quite hot.

 

Yesterday I turned the Mikuni Heater on (I think its an MX40 ?) and it ran OK for about an 1/2 an hour then I noticed the radiators were not hot, so checked the control panel and the red malfunction lamp was flashing.

 

I tuned the system off wait about a couple of minutes then turned it back on, now the unit does not run at all, any ideas ?

 

FYI I have about 1/4 tank of diesel, the room thermostat was set to 25 and it was well below that in the cabin.

 

[nicknorman]

Inside the black control box on the heater is an LED light. When there is a malfunction it gives a number of flashes. If you tell us the number of flashes we can look at the manual and tell you what is wrong.

 

Presuming the battery supply voltage is adequate, the next most likely thing, if the heater makes no attempt to run at all (ie no faint whirring sounds from the water pump) is that the glowplug has blown. These should be considered "consumables" and I always carry a spare. I think we have got through 3 in 4 years. Quick and easy to change, about 5 minutes if you know what you are doing.

[Albion]

Inside the black control box on the heater is an LED light. When there is a malfunction it gives a number of flashes. If you tell us the number of flashes we can look at the manual and tell you what is wrong.

 

Presuming the battery supply voltage is adequate, the next most likely thing, if the heater makes no attempt to run at all (ie no faint whirring sounds from the water pump) is that the glowplug has blown. These should be considered "consumables" and I always carry a spare. I think we have got through 3 in 4 years. Quick and easy to change, about 5 minutes if you know what you are doing.

The glow plugs will often keep failing due to carbon build up along the lower part of the coil winding of the glow plug. This is caused by the two angled air swirl holes in the glow plug holder being blocked. It is essential to keep these clear or the problem will recur again and again. When the carbon builds up on the coil windings then, due to the inter-turn short so caused, it often keeps blowing the main fuse just as the unit goes into glow plug heat mode just after the combustion chamber air purge stage.

Roger

[nicknorman]

The glow plugs will often keep failing due to carbon build up along the lower part of the coil winding of the glow plug. This is caused by the two angled air swirl holes in the glow plug holder being blocked. It is essential to keep these clear or the problem will recur again and again. When the carbon builds up on the coil windings then, due to the inter-turn short so caused, it often keeps blowing the main fuse just as the unit goes into glow plug heat mode just after the combustion chamber air purge stage.

Roger

Yes true, but in our case there is no carbon build up and the holes are completely clear, ditto the mesh. I think the glowplug inevitably has a limited life even under ideal conditions. I blew the last one after several start attempts required to prime the fuel system after I had removed the fuel filter for cleaning, probably my fault for being on shore power at 14.4v at the time.

 

Regarding the OP, it can't be the main fuse blown because the switch light is still flashing. The control box checks for continuity of the glowplug circuit and If it finds the glowplug has blown it doesn't attempt to even start the light-up process.

[Blazeaway]

Thanks folks, on my way down there shortly so I'll take heed of the advice and see what I can find.

 

Thanks again for your help.

[Albion]

Yes true, but in our case there is no carbon build up and the holes are completely clear, ditto the mesh. I think the glowplug inevitably has a limited life even under ideal conditions. I blew the last one after several start attempts required to prime the fuel system after I had removed the fuel filter for cleaning, probably my fault for being on shore power at 14.4v at the time.

 

Regarding the OP, it can't be the main fuse blown because the switch light is still flashing. The control box checks for continuity of the glowplug circuit and If it finds the glowplug has blown it doesn't attempt to even start the light-up process.

I didn't suggest that this was anything to do with the OP's reported fault, merely that it was a fault associated with the inter-turn shorting of the glowplug.

Roger

[NMEA]

Firstly you do not have an MX40, you have an MX60, that is easy to spot. Coil wound glow plugs are a "sure to fail item" that's why modern units have a ceramic pin instead, however it is unwise to assume anthing, as has been suggested have a look at the control box which is mounted close to the heater and count the flashes, no need to ask what the fault code is as there is a list of codes on the box itself. The Mikuni range is now defunct and spares, even some consumables are becoming difficult to source off the shelf without a wait ( glow plugs are not an issue as they are not a Mikuni part) so let's hope it's something simple and no real surgery is required, I am squirreling away any servicable parts I can lay my hands on.

Edit to add, the flashing light on the MX60CFD control panel simply means it's trying to start, it will glow steady when the flame is established. The malfunction light tah is flashing means just that. Also a room stat and or Thermstatic Rad valves are not a good idea on these evaporator heaters.

Edited February 1, 2015 by NMEA

[Blazeaway]

I've been and had another look at it and can report as follows:

 

I can't find anything like a control box, just the panel in the photo and the heater unit.

 

The unit does try to fire up, it goes through a sequence, and I can faintly smell diesel smoke then it shuts down and the panels malfunction light flashes continuously, about once per second.

 

I did find a bad connection on a multiplug and fixed that but still same outcome.

 

So still searching for the problem.

[nicknorman]

I've been and had another look at it and can report as follows:

 

I can't find anything like a control box, just the panel in the photo and the heater unit.

 

The unit does try to fire up, it goes through a sequence, and I can faintly smell diesel smoke then it shuts down and the panels malfunction light flashes continuously, about once per second.

 

I did find a bad connection on a multiplug and fixed that but still same outcome.

 

So still searching for the problem.

I'm not familiar with the mx60 but the mx40 has the control box mounted on the side of the heater, in ours it's just a rectangular black box perhaps 6" x 4" x 2". One screw to remove the lid and then you can easily see the LED and count the flashes. Your time will be best spent trying to find this box / led rather than guessing the problem.

 

Edit: looks like the control box is mounted separately on the MX60, but if you follow the wires from the switch panel, they should go via the control box before reaching the actual heater.

Edited February 1, 2015 by nicknorman

[NMEA]

The length of cables that were supplied with an MX60 kit mean the control box must be close to the heater, The symptoms you describe in post #8 are simply fail to ignite, that could be no fuel, 1/4 tank reading is irrelevant if it has a dip tube correctly installed that will be well off the bottom of the tank, or the unit could be fouled with carbon. You can check the fuel presence by disconnecting the output side of the fuel pump and see if you get spurts during the start up attempt. The MX60 is different in many respects from the MX40, including the glowplug boss and control box to mention just two so let's not confuse the issue with well meaning but uninformed and potentially misleading information.

Edited February 1, 2015 by NMEA

[Blazeaway]

I checked all over near and around the unit still didn't find a control box spoke with previous owner and he didnt know one either, does it definitely have one ? On top of the unit is a 2x2x6 inch box with cables in/out is that it, 4 screws not easy to get at so couldnt open it.

[NMEA]

No, the box mounted on top of the MX60 is a cover for the resistor unit, but on some there are also timer modules too, best if you PM me an email address and I can send you the parts manuals and workshop manual, there are actually two models of MX60 so I'm working a bit in the dark if we get into anything more specific.

[nicknorman]

The MX60 is different in many respects from the MX40, including the glowplug boss and control box to mention just two so let's not confuse the issue with well meaning but uninformed and potentially misleading information.

In my defence, mi'lud, I was sucked in by the OP mentioning MX40, although of course a proper look at the photo of the switch clearly shows MX60!

[NMEA]

I wouldn't worry, actually I forgot there were two models of MX60 for a moment, I don't see one from one year to the next but Jan was a bit like busses I had three to sort, one a scrapper and two fixable.

[Blazeaway]

No, the box mounted on top of the MX60 is a cover for the resistor unit, but on some there are also timer modules too, best if you PM me an email address and I can send you the parts manuals and workshop manual, there are actually two models of MX60 so I'm working a bit in the dark if we get into anything more specific.

Cheers I'll pm a msg. Got a photo of the unit just having trouble uploading it.

[OldGoat]

Firstly you do not have an MX40, you have an MX60, that is easy to spot. Coil wound glow plugs are a "sure to fail item" that's why modern units have a ceramic pin instead, however it is unwise to assume anthing, as has been suggested have a look at the control box which is mounted close to the heater and count the flashes, no need to ask what the fault code is as there is a list of codes on the box itself. The Mikuni range is now defunct and spares, even some consumables are becoming difficult to source off the shelf without a wait ( glow plugs are not an issue as they are not a Mikuni part) so let's hope it's something simple and no real surgery is required, I am squirreling away any servicable parts I can lay my hands on.

Edit to add, the flashing light on the MX60CFD control panel simply means it's trying to start, it will glow steady when the flame is established. The malfunction light tah is flashing means just that. Also a room stat and or Thermstatic Rad valves are not a good idea on these evaporator heaters.

 

 

Oh dear - do I read that aright? "Mikuni range is now defunct"? Before I panic and ring those nice folks in Fareham in the morn - to me that means ALL their heaters; MX40 and 60.

Shurely not - lots of info and items for sale on the importers' site for the '40, though that could not mean a lot.

Whilst I've disturbed your Sunday rest could you shine some light why my battery monitor system insists the glow plug is drawing 500 amps, 'specially as the CB is 25 amps... I assume there's some noise around to fool the electronics, if so how to suppress?

[NMEA]

All their heaters not just the MX40 & MX60 but the MY 16, 30 & MX range too they are still providing spares back up obviously and I think Mikuni UK may still have a couple of 24v units available but Mikuni ceased manufacture in January. Mikuni UK are also now importing a replacement range if heaters, they, like the old Mikuni are priced at the bottom end of the market but more sophistocated than the Mikuni which I have always liked despite their somewhat agricultural nature. A very competant and decent heater but very long in the tooth in design and efficiency terms. I do know Mikuni UK tried to order sufficient stock to continue supply for a while as they have a loyal following but they never arrived, I have been fitting their new range of air heaters for a while now.

Oh dear - do I read that aright? "Mikuni range is now defunct"? Before I panic and ring those nice folks in Fareham in the morn - to me that means ALL their heaters; MX40 and 60.

[Blazeaway]

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[nb Innisfree]

Two models of MX60, 12v and 24v, 12v is more basic electrically. 24v is electrically similar to MX 40. Can't speak for MX60 12v model but 24v one has an overheat reset button on the top of the box mounted on top of heater, has a blank rubber grommet to keep water out, pressing firmly on this will activate the reset button underneath.

[NMEA]

Two models of MX60, 12v and 24v, 12v is more basic electrically. 24v is electrically similar to MX 40. Can't speak for MX60 12v model but 24v one has an overheat reset button on the top of the box mounted on top of heater, has a blank rubber grommet to keep water out, pressing firmly on this will activate the reset button underneath.

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.

[OldGoat]

All their heaters not just the MX40 & MX60 but the MY 16, 30 & MX range too they are still providing spares back up obviously and I think Mikuni UK may still have a couple of 24v units available but Mikuni ceased manufacture in January. Mikuni UK are also now importing a replacement range if heaters, they, like the old Mikuni are priced at the bottom end of the market but more sophistocated than the Mikuni which I have always liked despite their somewhat agricultural nature. A very competant and decent heater but very long in the tooth in design and efficiency terms. I do know Mikuni UK tried to order sufficient stock to continue supply for a while as they have a loyal following but they never arrived, I have been fitting their new range of air heaters for a while now.

 

 

Oh.......

Best lay in a stock of parts (the only thing I've needed in 15+ years was a glow pin thinghy. Where can I get a 24V pin?

 

Thanks for the info at least!

[NMEA]

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.

Edited February 1, 2015 by NMEA

[Blazeaway]

Finally managed to get the picture sorted....

 

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

 

[nipper]

Um!

 

Just a suggestion from someone who probably doesn't know what he is talking about.

 

As it is a new boat to the OP, I was wondering whether the fuel system for the heater had its own fuel filter?

I know mine has.

 

But, there again, if it was a new boat to him, he would, of coarse, changed all the boats filters, wouldn't he?

 

Nipper

 

[Blazeaway]

Um!

 

Just a suggestion from someone who probably doesn't know what he is talking about.

 

As it is a new boat to the OP, I was wondering whether the fuel system for the heater had its own fuel filter?

I know mine has.

 

But, there again, if it was a new boat to him, he would, of coarse, changed all the boats filters, wouldn't he?

 

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.