Honda BF150 uneven rpms

M

msgchef

New member
Got Seaweed out for my first run. I noticed something in the engine rpms, at 4000 the engine seemed to be uneven in its sound, just a bit of up and down in revs rather than one smooth sound. It disappears at higher rpms and lower. I didn't play around too much to determine the range but will do so next outing. Hopefully I am explaining it well enough to get some guidance.
thx
Paul
 
Indeed, lots of info
Most not very complimentary of Honda Support.
My inexperienced question is.. Other then probable performance issues is there a negative effect of the health of the engine running extended time at that rpm level.
thx
Paul
 
IF it's the same issue I had with the ECM on Plan C, Les at EQ said it would not be a problem. Hopefully it's either under warranty or you have better luck with customer service than I did.

Good luck!
 
oh no, 2006, way past that. Talking to Ray, previous owner, he seems to be in the camp, it's slight spot of in between economical running of the engine and just when the V-Tech system kicks in to add power with less fuel economy. He said when he ran it, it was a range of 100-200 rpms and just try and stay out of cruising in that range.
We'll see with more time on the water, what I learn.
thx again
Paul
 
I had a similar problem with a new Honda 50 efi. Found water in the gas and debris in the gas tank. A clean out and fresh gas fixed it. Good luck
 
I agree with Marty
rule out bad gas, water in fuel, dirt, dirty fuel system, old fuel filters, replace gasoline with alcohol free gas,check battery cables at battery and on outboard, etc .......first
 
Honda EFI engines around that time frame had a problem with surging. Honda had a fix for it, don't know if it was a recall or not.
 
That's a good checklist to work, it will take some time. Some of those items are visual checks, how does one check for bad/old gas? I have 85 gal left from Prev Owner. It will take some time to run thru that.
 
My '08 BF90D had this problem. It was a few hundred RPM surge/sag. It occurred in mid range RPMs. Above 4K and below about 2K the surging did not occur.

Honda changed the ECM to fix it. I just squeezed in before the expiration of the warranty.

The guy who had the boat before me (he bought it new) said he never had a problem with the motor. However, he only ran it fast or slow (trolling).

Look for Honda Service bulletin 61 in the C-Brats tech library.
 
Pull and inspect plugs
Either re use them or replace, most will do the later for peace of mind and is inexpensive.
Add anti seize to threads and boot grease to the tips

Check plug wires for cracks or breaks and check they firmly
attach to the plugs.

It could a bad wire, loose plug or poor connection.
You are checking all related components but condemning the ECM which is expensive

How old is the gas?
An external fuel filter like a Racor that uses a clear bowl is very useful to check for water and dirt
If not present I recommend installing one
Then take a cruise for a couple of hours and check the bowl contents.
The tanks may need to be drained and cleaned,

If ECM is the problem, I would post the info with us and file a request for replacement with a dealer and Honda.
Maybe they will replace it and offer at reduce price, and they want to see the bad comments. It is worth the effort
 
m2cw having a good relationship with a dealer, shop and mechanic would be better and they could work magic (maybe) with Honda.
 
You are close to Mobil East Marine in Alliance, NC. They are an excellent dealership for CDorys and Honda outboards. I would discuss your problem with Gene the Owner. He has always been able to help me with my outboard issues. Good luck!
 
Yes, Gene is going to be my mechanic. I met him prior to buying and he spent allot of time sharing knowledge. He runs a good shop.
thanks
 
We had a very slight pinch (we had our paddles in the splash well) in the fuel line that caused a similar problem.

Good luck.
 
Get a portable gas tank and hook it up to the motor. See if the problem is still there. This was one of the many things Honda made the shop were I took my boat do before they would change the ECM (even though there was a service bulletin describing the problem and the solution).
 
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