2006 Honda BF150 Purchase!

Hello All,

Been lurking here for quite a while, and after purchasing a "new to me" boat this spring I figured I would add in my experiences/seek advice when need be!

My engine is a very low hour 06 BF150. Yes, it sat for a while, and yes it was/is a saltwater boat. It received all new tstats and fuel filters prior to my purchase. There is some corrosion on the exhaust manifold, but no leaks are present. The side flush port was also clogged with salt - which has been cleaned out. Boat idles fairly smooth, and will max at 6000 RPM. I do have a few questions about how it is operating, and will be ordering the service manual in August.

1. I replaced the impeller after I purchased it, and the tell-tale was slightly stronger. It was like this four about 20 hours. However, after running in freshwater this past week (~10 hrs), it seems to be weaker. Yes, I may have picked up weeds/sediment, but attempting to run weedwacker line through the telltale yielded no difference. No overheat alarms, but I do think it is running warmer overall (flipping the engine support bracket in that area seemed warmer than normal). Before I drop the LU, inspect the impeller, remove the top tstat, and do a backflush, any other ideas? I am also thinking of salt away, not just normal flushing, being added to the list after each trip.

2. The trim assembly seems to be making more noise when lowering all the way to its lowest position. One of the rod-piston water seals or gasket (it is black) is not intact (it is there, just frayed and sticking up). I am thinking possible air or water intrusion causing the hydraulic noise - can this be a simple ATF fill process and do the gasket change over the winter?

3. After the impeller change, shifting has been rougher. I have read that placing the LU back on is very finnicky. Everything is aligned (i.e. flat space facing front). However, based on age, I am also thinking shifter cables may need some adjustment now that I have been using it continuously.

Sorry for the first-post questions - I will do my best to help out!

1/ Low water pressure is usually caused by a stuck open thermostat or partial blocked where the tell tale water exits the block, best way to clear this is with compressed air while the engine is running either on a hose or in the water. Check thermostats anyway to be sure they were in fact changed and not just checked.

2/ Trim caps should be changed complete with new seals. Don't risk getting water, especially salt water into the unit or you may be up for a new valve body too, rather fix now.

3/ You may have put excessive grease on the shift shaft which can result in a hydraulic effect putting undesirable upward pressure on the shift shaft resulting in the described issue. To isolate the problem, disconnect the shift cable and try shifting manually the the motor with engine off and gently turning the prop to align the dog clutch. If it feels okay then you have a cable issue, if not, then remove the lower again and check .

iang6766 said:

1/ Low water pressure is usually caused by a stuck open thermostat or partial blocked where the tell tale water exits the block, best way to clear this is with compressed air while the engine is running either on a hose or in the water. Check thermostats anyway to be sure they were in fact changed and not just checked.

2/ Trim caps should be changed complete with new seals. Don't risk getting water, especially salt water into the unit or you may be up for a new valve body too, rather fix now.

3/ You may have put excessive grease on the shift shaft which can result in a hydraulic effect putting undesirable upward pressure on the shift shaft resulting in the described issue. To isolate the problem, disconnect the shift cable and try shifting manually the the motor with engine off and gently turning the prop to align the dog clutch. If it feels okay then you have a cable issue, if not, then remove the lower again and check .

Click to expand...

I pulled the top tstats yesterday. Some crud in there, but not nearly as bad as I thought it would be. There is definitely buildup against the heat sensors, so I need to clean those out anyway. I plan on dropping the lower unit anyway (check impeller, do the back flush), as it shifted fine prior to my lower unit service. I am hoping it is not a cable issue, as that appears to be out of my comfort zone (I have rebuilt carbs and motors, but the cables scare me!).

New seals will be ordered this weekend - it looks like a fairly simply job, but I also need to get my hands on one of the tools to do the repair. Is that a marine-only application, or can I get one of those at an advance/harbor freight/etc.?

Thanks for your response! i appreciate it!

This afternoon I removed the LU. The impeller and housing look like the day I swapped them. I flushed the lower unit, but nothing to speak of coming out.

On to the engine. I pulled the tstats, and ran white vinegar for about 45 minutes. This was followed with a high pressure hose flush. I collected the "evidence" and hopefully the picture attaches. Buttoned her up, definitely more pressure at idle from the tale.

On another note, not as much noise from the trim today...I'm not going to ignore it!

Still had some telltale issues even after the vinegar flush. It would start great for 2 seconds, then go to minor flow. I flushed all the lines and no fix.

After a morning of fishing, I was determined to figure this out. I pulled the line from the block to the vst, and that flowed great on the hose attachment. When I unplugged the top hose to the tell tale, minimal flow.....found the issue!

Took off the cover, and low and behold a nice big deposit in the porr. It looks like it would dislodge, then at startup get forced in. Removed it, cleaned up the area, and ran on the muffs...finally have normal flow!!!

Excellent! "Big deposit in the porr"???? Did you mean port? If so, which one?

Port using my phone is a bad idea!

The most frustrating part was how easy it crumbled in my hands. But more fishing tomorrow, so hoping for smooth running.