Honda BF100A overheat warning when flushing

[chris101]

Hi,

I was flushing my 4 month old (5 hours run time) Honda BF100A today on the drive, using bellows & garden hose, had what looked like a steady flow from the tell-tale and could feel the water temperate warming up as normal, ran it for probably no more than 10 minutes when I heard the engine overheat warning alarm, with same message on the computer display, I immediately shut the engine down.

On restart a minute later it immediately came up with same warning, so left it to cool for 5 minutes, warning went off. Tried the same process again and after 5 or 6 minutes no repeat warning so shut it all down again.

Any ideas what I've done wrong here? Always flush it within 4 hours after use in saltwater, and its only been out 3 times.

Any chance the engine could be damaged now?


Many thanks

[spartacus]

I doubt you've damaged it.

Depends by kind of muffs you have - I've seen versions where the hose splits so water is fed in on both sides of the water inlet. If in doubt - it may just be easier to run the engine in a large barrel so the leg is fully submerged.

Could just be the overheat alarm is very sensitive. I'm sure other Honda owners will add to this.

[chris101]

Many thanks, I'll be trying it again tomorrow with the leg in a barrel.

Now I just need to work out how to drain off 60L of E10 fuel!

[jeffstevens763@g]

Our water pressure is low if I’m using the hose and the wife turns the kitchen tap on the hose drops off dramatically just a thought

[Orwell boy]

[QUOTE=chris101;846600]Hi,

I was flushing my 4 month old (5 hours run time) Honda BF100A today on the drive, using bellows & garden hose, had what looked like a steady flow from the tell-tale and could feel the water temperate warming up as normal, ran it for probably no more than 10 minutes when I heard the engine overheat warning alarm, with same message on the computer display, I immediately shut the engine down.

On restart a minute later it immediately came up with same warning, so left it to cool for 5 minutes, warning went off. Tried the same process again and after 5 or 6 minutes no repeat warning so shut it all down again.

Any ideas what I've done wrong here? Always flush it within 4 hours after use in saltwater, and its only been out 3 times.

Ha Ha ,just a Honda thing i think,i have 100hp honda and when running in winter on muffs i too get alarm sounding after a short while ,as jeff suggests poor water pressure is contributary ,personally i have had honda 90hp previously and that was same ,wouldnt worry ,doubt it will do it on the water or in your tank ,but dont run it with the alarm going
Mabe you dont know but with your honda you can buy an engine drop lead and a nmea2000 starter kit and light up all the data including engine temp on your garmin which i am guessing will be standard on your highfield !

[Orwell boy]

Originally Posted by chris101

Many thanks, I'll be trying it again tomorrow with the leg in a barrel.

Now I just need to work out how to drain off 60L of E10 fuel!

Take the inlet off the fuel filter and join a piece of fuel pipe through the drain plug in the hull (this avoids any need to go uphill) ,catch your fuel in a can on the floor behind the trailer

[chris101]

Many thanks for the replies, quite reassuring. Will have a go at draining the fuel tomorrow, finally got some time on my hands to get these little jobs done having come down with Covid!

[JohnW]

Originally Posted by chris101

Many thanks, I'll be trying it again tomorrow with the leg in a barrel.

Now I just need to work out how to drain off 60L of E10 fuel!

Why do you need to drain the E10?

[chris101]

I just assumed that it was best to start the new season with a fresh tank of fuel (as it wont be used over winter)

[charliee]

Hi Chris101, Personally I'd get the E10 out and run some E5 thru. Long term the E10 will separate and the ethanol will absorb water and this may lead to issues down the line.
I suspect the heat alarm is due to a lack of pressure - can you get the prop and pickup into a large bucket of water as it works much better that muffs?

[Matt]

Agree with getting E10 out of it over the winter.
This year I've actually drained the E5 out of my tank - and am currently jerry can-ing it into the cars.

Re overheat - yeah. it's not just about getting a bit of flow, but also a bit of pressure to go into all the right nooks & crannies. In the old days, when people took thermostats out of their Merc V6's, without a restrictor washer they wouldn't get enough pressure, a hotspot would develop and they'd blow the motor. The americans think the water needed time to warm up - but this is BS and doesn't follow any thermodynamic principles.

What it did need was a bit of back pressure to get shot of any air or steam pockets in the block.

Anyway, you'll be fine, modern engines & ECUs are pretty decent at protecting you.
On my motor (I built it & the ECU), I struggle to keep it cool on the hose at all, there's just too much heat coming through the exhaust manifolds. I've also put a temperature rev limiter in - so if the temperature goes over, I think, 80 (73C thermostat), it limits me to a fast idle.

[midlife]

My 225 Honda does the same , they don’t like running on muffs for longer than 5 mins and need lots of water flow