Jump to content

Mikuni mx40


Oxford Landing

Featured Posts

Hi All

Early this year had a bit of of problem with the unit mikuni mx40 heater whilst running it decided to just put smoke out of the exhaust, it was like a scene out of James Bond movie anyway all shut down decided to remove the unit and send it for servicing,  the unit returned late so had to fit it after my holiday so a bit of a time delay, once fitted would not start up and then after several attempts the glow plug gave up(melted), contacted the service company who said it was usually I must have tried it too many time without letting it cool down, possible so I ordered another glow plug fitted and guess what happened on the first try the glow plug has given up (melted) and now I cannot now get it out of the housing.

Has anyone had similar faults

If so how was it sorted

Or do I just put it in the bin

Any recommendations for a reliable unit.

I will be contacting the service center on Monday but I'm not putting in another glow plug.

Link to comment
Share on other sites

22 minutes ago, Oxford Landing said:

Hi All

Early this year had a bit of of problem with the unit mikuni mx40 heater whilst running it decided to just put smoke out of the exhaust, it was like a scene out of James Bond movie anyway all shut down decided to remove the unit and send it for servicing,  the unit returned late so had to fit it after my holiday so a bit of a time delay, once fitted would not start up and then after several attempts the glow plug gave up(melted), contacted the service company who said it was usually I must have tried it too many time without letting it cool down, possible so I ordered another glow plug fitted and guess what happened on the first try the glow plug has given up (melted) and now I cannot now get it out of the housing.

Has anyone had similar faults

If so how was it sorted

Or do I just put it in the bin

Any recommendations for a reliable unit.

I will be contacting the service center on Monday but I'm not putting in another glow plug.

Not sure why you wouldn’t be able to get it out of the housing, did you over-tighten it? Anyway it does require several cycles to get the fuel up into the heater if prime is lost. I made the mistake of doing this whilst the boat was plugged into shore power with system voltage up at 14.4v, on the third go it blew the glowplug. I fitted a new plug and repeated the process just from the batteries (system voltage 12.5v or so).

I’ve found the quality of glow plugs a bit variable. Any nicks in the heating wire causes a local overheat, and if the coiling isn’t evenly spaced (ie the wire well separated from the adjacent turn) then this can cause local overheating and even, in extremis, a short circuit between turns which significantly increases the current thus overheating the rest of the plug. I’d try again, carefully examine the heating element and do it on battery power. You have to get the old one out first, of course!

Link to comment
Share on other sites

I found that the glow plugs were not the best part of the mikuni set up. I used one for 4 plus years but had to get it serviced more than I would have liked though it certainly turned the heat out when needed. Mikuni was liked by Steve Hudson on his boats but I prefer webasto and have found them more reliable and cheaper and easier to source any bits. I wouldn't bin it I liked mine but if you are fed up then go for webasto.

Link to comment
Share on other sites

Thanks have tried a new plug after getting the old out (element burnt and was catching) running on battery power only but still won't start, has never run since service and do not want to take it off at the moment any more ideas diesel dribbles out of pipe and have enough battery power ?

Link to comment
Share on other sites

On 08/12/2017 at 18:12, Oxford Landing said:

Hi All

Early this year had a bit of of problem with the unit mikuni mx40 heater whilst running it decided to just put smoke out of the exhaust, it was like a scene out of James Bond movie anyway all shut down decided to remove the unit and send it for servicing,  the unit returned late so had to fit it after my holiday so a bit of a time delay, once fitted would not start up and then after several attempts the glow plug gave up(melted), contacted the service company who said it was usually I must have tried it too many time without letting it cool down, possible so I ordered another glow plug fitted and guess what happened on the first try the glow plug has given up (melted) and now I cannot now get it out of the housing.

Has anyone had similar faults

If so how was it sorted

Or do I just put it in the bin

Any recommendations for a reliable unit.

I will be contacting the service center on Monday but I'm not putting in another glow plug.

Wondering if you have some Water mixed with the Fuel.should the Gloplug have Water deposited on it Shorting and rapid corrosion can Occur.

Does the Gloplug actually get Hot and are you getting adequate Voltage at the Gloplug Terminals?

You could try switching on the heater with Gloplug disconnected and one connection removed from the Fuel pump,if Smoke exits the Exhaust during this Test then do it once more.you may have unburnt Fuel from previous attempts and General Damp in the Combustion Chamber.

 

 

 

 

 

 

 

Link to comment
Share on other sites

You’d think if you have fuel, air and heat you would get combustion. The controller checks for continuity on the glowplug before commencing the startup cycle, so it likely to be “in circuit” but still a good idea to check the voltage actually on the glowplug. There are a few fuses in or near the controller, maybe check the condition of those (corrosion etc).

You have fuel dripping out. Well liquid anyway.

the air pump will be running or you’d get a pre-start error.

where they all mix together there is a gauze thingy which enables the evaporation and hence combustion - have you checked the condition of the gauze? Also there are a couple of air holes in the spigot thing the glowplug fits into - check not blocked with carbon.

Link to comment
Share on other sites

The control box will not let the heater start without the glow plug añd pump connected. A self check cycle is built in prior to fire up enabled. 

It is important that the full battery voltage gets to the heater, so check for bad connections.

Battery needs to give at least 12 volts at the heater .

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.