Logo
FULL SITE MENU

15 hp engine cut out

T

Trent_QLD

New member
Hi all,

I've been having some trouble with my 2003 15 hp pull start tiller steer, it starts and runs perfectly for 10-20 min then cuts out suddenly (as if the kill switch is tripped). It won't restart until the motor is completely cooled down, however if the spark plugs are pulled out then put back in it starts up straight away and will run for 5-10 min then cut out again. I've replaced the spark plugs, tested the kill switch, checked the wiring loom, coils, heat sensors, cdi ect... for continuity and correct resistance to no avail. I've checked the fuel lines for flow and contamination... all seems good. Inspected the cooling system... all good there too. I've seen in previous threads of similar problems but have not seen any that have resolved the issue. Has anyone got any suggestions?

Thanks,

Trent
 
Last edited:
You said you inspected the cooling system....did you try removing the thermostat and running the engine without it? It may be possible that the thermostat is stuck closed or partially closed and causing the motor to overheat, then shut down.

The removing the spark plugs fix may just be a coincidence. I will have to think about that.

Another possibility is that it is running rich and flooding out. Letting it sit lets the plugs dry off and pulling the plugs does the same. Did your old plugs look black?

Just throwing that out there.....

While it is running pull and push and wiggle on all the cables and connections and see if that makes the engine fail. AKA....the wiggle test.

Mike
 
When it happens, if you can make it happens.
perform spark test. See if you still have spark..or not.
Dont do any ohm test.
hondadude said:
You said you inspected the cooling system....did you try removing the thermostat and running the engine without it? It may be possible that the thermostat is stuck closed or partially closed and causing the motor to overheat, then shut down.

The removing the spark plugs fix may just be a coincidence. I will have to think about that.

Another possibility is that it is running rich and flooding out. Letting it sit lets the plugs dry off and pulling the plugs does the same. Did your old plugs look black?

Just throwing that out there.....

While it is running pull and push and wiggle on all the cables and connections and see if that makes the engine fail. AKA....the wiggle test.

Mike
Click to expand...
 
Thanks for the advice guys.

The spark test was one of the first things I checked, had a good spark after it cut out.
The old spark plugs looked in good condition, they were less than a year old when the problem started.

I might have made a bit of headway this afternoon, I took Mike's advice and ran the motor without the thermostat, it ran for over 30 min without cutting out. The slightly puzzling thing is that I put the thermostat back in and it ran for another 30 min without cutting out. By that stage it was getting dark and the mosquitoes were starting to bite so I gave up. Is it possible that there was a partial obstruction in the cooling line and the extra flow from running without thermostat dislodged and flushed it out? I had previously removed the thermostat and tested that it opened correctly (which it did) but assumed the cooling system was working as there was plenty of water coming out of the tell-tail and exhaust outlet.

A cooling system problem is starting to look most likely as I replaced a few components about 10 hrs before this problem began. I lent the boat to my brother for about 12 months during which he didn't flush out the motor thoroughly enough, salt built up around the flushing port and caused considerable corrosion to the jacket and wiring brackets. I replaced the jacket, seals, wiring brackets, bolts and thermostat. Instead of replacing the flush valve and spring I put a 25 mm bolt and o-ring in the port (not sure if this should be done or not). I'm hoping it was an obstruction that has been cleared but I'm not holding my breathe, will find out before long when I take the boat out for a proper run next weekend.

Trent.
 
Hi guys

Gave the motor a run this weekend...no good.

Same issue, cut out after 9/12 min of running. Took the thermostat out and tried to restart it, no go. Removed the spark plugs for a couple of minutes then put them back in and got it running, but only for another 5 min. Unless it's a faulty temp sensor I think I can rule out over heating.

It's all been bit too frustrating and after some deliberation (and a sale at the boat shop) I have decided to buy an 18 hp tohatsu.

I think the old honda is going to be scrapped for parts... oh well it's had a good run.

I'm still open to any suggestions, it would be much better to keep it running.

Cheers,

Trent.
 
Last edited:
Back
Top