2006 Johnson 9.9 CYL Head

[Seafarer57]

Hello, I have a question about the cylinder head on a 06 Johnson 9.9 J10RSDC. The parts list has a 338221 for the 10R and a 350949 for the 15R. What's the difference in them? The power head also has different part numbers but the crank and piston are the same so the displacement should be the same. Are the water jackets larger because of the additional RPM on the 15R? Thanks

 

[Calibra]

I have a 1999 2 Stroke 15HP Johnson engine that I purchased. After 15 or so minutes it locked up.
The end result was I needed to rebuild the engine. The power head was so screwed I needed a new one.

I ended up purchasing 10HP power head and couldn't see any difference between them.

Once all put back together, my 15HP pushes my boat at 28Knotts full which is full of gear.

 

[ondarvr]

There aren't many differences between the two models and most parts are interchangeable, but don't expect to get 15hp out of the 9.9 by changing only one item.

 

[Seafarer57]

Yea, I get what your saying. I'm studying the parts list and trying to understand the differences in the event I did. I have an older model 97 15R. The 15R also calls for a water passage grommet (1ea) in the block, curious why and what's it's purpose is? Thanks

 

[Calibra]

From 1994 I'm confident only the carb is different.

 

[Seafarer57]

The carb and also the reeds are the biggest difference. Your CYL head swap tells me the 9.9 and 15 are not a factor, I think the only other thing is the water passage jacket, I might have to get a Johnson expert to answer that question... Thanks

 

[Seafarer57]

Johnson part# 345188 GROMMET, water passage. Anyone in the forum an expert on Johnson small outboards explain the purpose of this parts purpose in a 2006 15R and why the 10R does not use it. Also what is the difference in the Engine blocks part# 438595 10R and 5005456 15R and are they interchangeable? Thanks

 

[ondarvr]

While not sure on that exact year, all the 9.9 and 15s I'm familiar with used the rubber grommet, it connects and seals the water tube at the base of the power head. It's a common problem when it swells up and blocks the flow.

The difference in the block could be anything from porting to a hole drilled for a small bracket, maybe even just painted a different color, but I've never experienced a problem swopping parts between the two.

 

[Seafarer57]

Thanks for the information Admiral and Calibra!

 

[Maraian]

Thanks for the information Admiral and Calibra!

Did you ever figure out this? Or where is 345188 grommet located?

 

[saltchuckmatt]

Did you ever figure out this? Or where is 345188 grommet located?

This is a 6 year old post, pretty sure you won't get any info.

Start a new post, post model number and ask what you are looking for or what your problem is.