ECU overheating?

[madness]

Hi, guys!

My ECU gets really HOT after few minutes of riding. No high revs, speed is under 60km/hour. And it is almost too hot to keep my hand on it. I suspect that ECU is overheating abnormally, and it causes ECU damage.

I'd like to ask about one thing... Could you please check it out on your SH? Just ride about 20 minutes and then put your hand on metal cap of ECU....

Thanks!

[madness]

Anyone? Please.
I wouldn't ask if in my city was any other Honda SH... In whole Russia i think i can count them by fingers...

[TommyXP]

In a short while I'll have time to perform this procedure and will let you know the results and hopefully provide some information that is useful to you.........

[madness]

Thank's!

Some ideas about problem of such overheating...

Now air flows from bottom to top, been heaten by engine's surface and heats ECU. Then this hot air flows into throttle body, and heats ECU again from inside:

Also this air is used by air-fuel mixture and it is not good, when it is hot or even warm - as colder as better.

In original set-up air flows from almost outside and it is not hot, it must be cools throttle body from inside and ECU too.

I'm already constructing a cooling system for ECU.... At least - to supply fresh air to filter, at most - whole throttle body (and ECU) will be included into scheme of air intake to filter.

RED marks areas i wannt to cut out and replace by grid, to allow more air to underseat space, where filter and thtottle body are.

[TommyXP]

I unbolted the seat attached a digital thermometer probe and then set the seat back in place and road 10 miles at ~50mph in 65° air temp. The ECU remained 'cool' to the touch........I can place my hand on it and know that it is less than 98.6°........... The thermometer never got above 100°........Now the fun begins!

[madness]

Thank you A LOT! It's quite usefull for me!

It means, ECU DOESNT HEAT AT ALL and reason is only in temperature of air around ECU.
...so sorry about 2 previously damaged ECUs! They were just burned... Life is Learning.

Well, now i'm sure, what to do! After i'll make those modifications, i'll write about results and make some photos.

[breaknwind]

Hello Madness.
My 2 cents would have to be the BBK. If you read about the BBK on this forum, you'll notice that the Malossi is known for excessive heat because of high compression. I noticed your remark about two head gaskets. That may work because it will lower the compression ratio. I don't know if it will be enough though. My stock SH never goes above 50% and the fan kicks on at about 45%.
If you decrease the compression, you will decrease the heat and also the HP. Even if you made the BBK's compression the same as a stock unit, you should still have more HP because of larger displacement.
IMHO if you can return the max operating temperature to the same as stock, the problems will stop.
Good luck

[madness]

Hi, breaknwind!

Yes, i read about BBK overheating. But my model of scooter has two radiators, as you can see at photo, and heats only with damaged gasket
In early spring i couldn't heat it to 50% with BBK. In stock it was only about 25% in spring, and when outside temerature less then +10C, i must close both radiators by tape, or temp drops to 0% of scale in 10 minutes of riding...
I'm not going to lower compression, but for case of summer overheating i'm planning to make extra ventilation of "underseat space" and split air flow to two - one directly to filter, another to engine body for cooling it.
See attached picture, GREEN intakes are for filter, RED are for engine body.

I'll post photos, when it will be done.

Anyway, thanks!

[madness]

Preparing to cut-out air intakes. Bottom cover will be cut too, it's just not been marked.

[madness]

Almost ready... Just mesh not installed.
Those white plastic "things" will supply fresh air to filter. Also upper-front intakes go there.
Middle-front and lower-front intakes supply air to engine body for cooling it.