D4 300 Impeller Change

[Bobby P.]

Had a little bit of a high temp read (197) when cruising at WOT with the boat loaded. When I dropped down to 3000 rpm, I went back to the typical 185 that is a constant.

I checked the strainer, but there wasn't much.

I figured I replace the impeller.

Is there a video out there for changing the impeller on the D4 300?

Thanks,
Bob

 

[Bruce Moore]

I'm only aware of this factory video for changing the impeller on a D3-200 but you might find some helpful tips.

Cheers,

Bruce

 

[Bobby P.]

Done!

Took about 45 minutes. 6 screws on the plate. Pulled old impeller out with good pair of needle nose. Used 3 zip ties to compress impeller. Slid her in and put it all back together.

a lot easier than the genset!

Bobby

 

[Goodtogo]

Did changing the impeller solve the problem? I had the same problem and changed the impeller and it did not solve the problem.
Mike

 

[JamesC28]

I run at 185 until I push it to WOT, then it goes up to 203. Assumed this was normal. Should I be worried?

 

[Cutwater28GG]

I’m at 185 all the time.

 

[Mr. Ed]

I run at 185 until I push it to WOT, then it goes up to 203. Assumed this was normal. Should I be worried?

Similar experience: 185 normal, and 196 and steady at WOT for more than 3 minutes. Seems okay to me.

 

[Bobby P.]

It did not change the problem.

I’m on a long run right now and have been running it between 3000 and 3250 for the last three hours. It stays right at 185. If I push it to wide-open throttle at 3400 it jumps to 193. I go back to 3000 and it jumps back to 185. I don’t recall this happening last year.

 

[Bobby P.]

Correction on my numbers. When I get to wide-open throttle at 3500 RPM it jumps to 196. I bring it back to 3200 RPM after about 2 to 3 minutes it drops back to 185. The odd thing is it never lose by one or 2° it jumps entirely between 185 and 196. I wonder what the factory team can say about this.