Mikuni Heaters

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catalina1

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Mikuni Heaters

I have Mikuni My16 heater
It gets luke warm and issues dense black/grey smoke from exhaust.
No fault code showing.
Anyone have any experience of these ?
Does it just want a clean. new glow plug?
It was serviced by dealer 2 years ago at great expense.
 
Re: Mikuni Heaters

Why not phone Mukuni


MY16 Technical Support

The MY16 heater is equipped with a self diagnostic fault finding system to aid repair should a fault occur. NOTE: Should any part fail or if there is a loose connection then the control box will not allow the heater to start at all and a fault code should flash in the control box window. The following table should assist you in repairing the heater if you follow the instructions step by step.

This list has been compiled from experience of the MY16 on the UK market. If you discover any new anomalies please inform us so that we may add them to our list.

ON/OFF Frequency Indicates:
1 : IGNITION FAILURE

2 : NO FLAME SENSING

5 : MOTOR FAILURE

7 : FUEL PUMP FAILURE

8 : GLOW PLUG FAILURE

9 : BATTERY VOLTAGE ABNORMAL or OVERHEATING



IF THE HEATER FAILS TO START BUT THE DIAGNOSTIC IS NOT FLASHING-CHECK THE THERMOSTAT BY LINKING THE TWO RED WIRES TOGETHER. ON INTIAL OPERATION OR IF THE VEHICLE HAS RUN OUT OF FUEL THE SYSTEM WILL NEED TO BE RE-PRIMED. THIS SHOULD BE DONE BY PUSHING FUEL THROUGH THE PUMP WITH A SYRINGE OR BY USING THE MIKUNI SP21 PRIMING PUMP.

IF THE GLOW PLUG FAILS, INSPECT THE BOSS FOR CARBON DEPOSIT OR STRAY STRANDS OF S/S GAUZE. CLEAN AS NECESSARY AND ENSURE THAT THE GAUZE IS NOT BURNT OR DAMAGED. IF IT IS REPLACE THE GLOW PLUG BOSS ASSY.

1. Ignition Failure
CHECK FUEL SUPPLY > FROZEN FUEL LINE? > CHECK AND CLEAN FILTER IN FUEL PUMP > CHECK FOR BLOCKED STANDPIPE > COMBUSTION AIR OR EXHAUST PIPE BLOCKED OR DAMAGED? > IF HEATER RUNS OK FOR APPROX 3 MINS AND STOPS-SUSPECT FLAME SENSOR > IF HEATER SMOKES BADLY AND STOPS AFTER 3 MINS STRIP DOWN AND DECOKE.

2. Flame Sensing
CHECK ALL PLUGS AND SOCKETS IN WIRING LOOM > LOOK AT FLAME SENSOR;IF THE SEALANT IS PUSHING OUT OF THE RETAINING NUT REPLACE WITH A NEW FLAME SENSOR.IF NOT CHECK FOR BAD CONNECTIONS ON PCB INSIDE GLOW PLUG COVER > CHECK CONTROL BOX.

5. Motor Failure
CHECK MOTOR FUSE 12V=7.5A 24V=5A > IF FAILED ENSURE THAT MOTOR SPINS FREELY > CHECK WIRING LOOM CONTINUITY > CHECK MOTOR > CHECK CONTROL BOX > CHECK FOR BAD CONNECTION ON PCB INSIDE GLOW PLUG COVER.

6. FUEL PUMP FAILURE
CHECK CONTROL BOX > CHECK CONTINUITY OF WIRING LOOM AND INSPECT FUEL PUMP TERMINALS FOR CORROSION > CHECK CONTINUITY OF FUEL PUMP.

7. Glow Plug Failure
CHECK GLOW PLUG FUSE=25A (IF APPLICABLE) > CHECK GLOW PLUG AND GLOW PLUG RESISTOR ON 24V MODELS. > CHECK CONTROL BOX > CHECK WIRING LOOM. NOTE:THE GLOW PLUG RESISTOR IS A DIFFERENT PART TO THE GLOW PLUG -DO NOT INTERCHANGE! [24 VOLT ONLY].

8. Battery Voltage Abnormal
THE HEATER WILL CUT OFF IF THE BATTERY VOLTAGE IS TO HIGH OR TO LOW. OPERATING RANGE FOR THE 12V MODEL IS 10.5 > 14VOLTS AND THE 24V MODEL IS 21 > 28 VOLTS. CHECK THE VOLTAGE AT THE HEATER WHILE IT IS RUNNING (SO THAT THE BATTERY IS UNDER LOAD) WITH THE BOAT ENGINE OFF AND AGAIN WITH THE ENGINE RUNNING TO ENSURE THAT THE VOLTAGE IS WITHIN THE OPERATING RANGE OF THE HEATER.

9. Overheating
MAKE SURE THAT THE HEATER HAS COOLED DOWN AND CHECK THE MOTOR FUSE > CHECK THE AIR INLET AND THE HOT AIR OUTLET FOR BLOCKAGE THE HOT AIR OUTLET FOR BLOCKAGE OR RESTRICTION. NOTE: OVERHEAT CUT-OUT WILL AUTOMATICALLY RE-SET WHEN THE HEATER COOLS DOWN.

View diagnostic flow diagram >
 
Re: Mikuni Heaters

Thanks for all Info Sailor man.
As I said there is no fault code showing,
The heater fires up and blows lukewarm air,
But Dense smoke from exhaust.
Mikuni are helpful but they just said bring it in
They are not open Sat. therefore I have to post it .
I dont really want a 150 pound bill if its just a matter of a new glow plug
 
Re: Mikuni Heaters

Re Heater
I would First clean heater sounds like severe sooting but there might also be a problem with supply voltage make sure your voltage is measured at the heater should be as high as possible over 12.5
To make sure you have sufficent voltage run the engine while you try it again.
 
Re: Mikuni Heaters

Had a Mikuni in a previous boat and found that there were large lumps of soot (more like coal!) in the exhaust between the heater and the silencer. Ran much better once that lot was cleared out.
 
Re: Mikuni Heaters

If its smoking its firing, so glow plug ok, sounds like lack of combustion air , so check no delamination of combustion intake air trunking (if it has any!) or obstruction of air intake OR is the fan motor slow because of bad bearings or obstructions or is the exhaust blocked, its due to lack of flow of combustion air!
Stu
 
Re: Mikuni Heaters

I had problems with mine (clouds of smoke) until I cleared out the exhaust. It had a lot of unburned diesel in it - caused by repeated attempts to fire it up when the glow plug earth was slightly dodgy and wasn't powering the plug properly.

If it's burning at all then the plug is probably OK. I'd check the exhaust and combustion air inlet.

Mark
 
Re: Mikuni Heaters

Hi Thankyou all for the advice, Tech info etc
Ill go for a good clean, intake and exhaust and check connectors first.
Will hopefully be able to give a result within the following weekends!!
 
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