Honda BF90D stuttering in the 3500 rpm range

skiptowns98033

As I advance the throttle between 3,200 and 3,800 RPM, the engine hesitates and recovers 2-3 times. below that or above that, it runs smoothly. Carl at EQ looked it up and said surging was either the low pressure fuel pump ($200) or the Electronic Control Module ($1,000) We had EQ do a 400 hour service a month ago when we bought it so everything - plugs, filters, etc - should be good to go. There's fresh fuel and and Stabil in both tanks.

Anyone had this happen? I think I know where this is heading - a new ECM for $1,000+ but if that's NOT it, there's no going back.

Thoughts?

Dan & Lori
Plan C
Cornet Bay, WA

Ray · Posted: Fri Sep 05, 2014 1:32 pm Post subject:

http://www.c-brats.com/viewtopic.php?t=19060

ssobol · Posted: Fri Sep 05, 2014 3:04 pm Post subject:

My BF90D had the ECU replaced under warranty for surging in mid RPMs. See the thread mentioned above. Have them check for Honda SB#61.

In my case Honda was reluctant to replace the ECU until all the other possibilities were eliminated. Honda would tell the repair shop to check something and report back. Then Honda would tell them to try something else and report back again. After a lot of checking (including the low pressure fuel pump), they finally replaced the ECU. It took awhile to do this, but it was all covered.

Honda probably would have saved a fair amount of money in shop labor and other parts by just changing the ECU right away (according to their own SB) instead of trying everything else they could think of first. Just by going by the number of engine hours accumulated in testing they spent more on labor than the ECU costs. When this happened to me the list price of the ECU was about $899. I'm sure the internal cost to Honda is a lot less.

I did get 4 months from free winter storage out of the deal too.

skiptowns98033 · Posted: Fri Sep 05, 2014 8:31 pm Post subject: Thanks everyone!

Looks like I have my answer. I appreciate the quick response!!

Dan