tn27 impeller 375688 now sierra 18-3001 ??

Outboard Related Only
crosbyman
Posts: 801
Joined: Tue Mar 10, 2015 11:39 pm
Location: Montreal Canada

tn27 impeller 375688 now sierra 18-3001 ??

Postby crosbyman » Mon Jan 22, 2018 12:25 pm

will the sierra 18-3001 fit directly as a replacement to the original 375688 prop ???

I have a spare JW impeller on hand.. would that fit a TN 27??

User avatar
Mumbles
CYBER SHERIFF
Posts: 3563
Joined: Mon Mar 09, 2015 3:42 pm
Location: Victoria BC

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby Mumbles » Mon Jan 22, 2018 1:03 pm

The new impellers thickness and diameter are the same as the original but the TN shafts were slightly larger in diameter than the later small OMC motors. If the impellers bore is honed out a bit, it will fit right in.

This applies to the TN-26 but I'm sure the TN-27 shaft size would be the same.
Still searching for a rudder and hardware to fit a KOBAN. ☺

Member of the http://uppercanadachapteroftheaomci.yolasite.com/

FrankR
Posts: 3011
Joined: Tue Mar 10, 2015 6:32 pm
Location: Florida

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby FrankR » Mon Jan 22, 2018 1:34 pm

Mumbles wrote:The new impellers thickness and diameter are the same as the original but the[color=#FF0080] TN shafts were slightly smaller in diameter than the later small OMC motors. If the impellers bore is honed out a bit, it will fit right in.

This applies to the TN-26 but I'm sure the TN-27 shaft size would be the same.[/color]

Slight typo there I think. The TN shafts are larger, not smaller than the 3, 5.5, 7.5. So, bore the impeller out to fit a TN-xx.

crosbyman
Posts: 801
Joined: Tue Mar 10, 2015 11:39 pm
Location: Montreal Canada

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby crosbyman » Mon Jan 22, 2018 3:16 pm

great I'll test this out with my spare impeller for a JW

User avatar
Buccaneer
Posts: 2244
Joined: Mon Mar 09, 2015 9:34 pm

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby Buccaneer » Mon Jan 22, 2018 3:48 pm

I saved this in my files from a long ago post,
regarding TN-28's. Are they they same as the TN-27's?
Also, a page regarding the carbon seals.
Attachments
TN27-28DSSealInstall.jpg
TN27-28DSSealInstall.jpg (123.24 KiB) Viewed 134 times
Sierra3001LBL.png
Sierra3001LBL.png (324.08 KiB) Viewed 134 times

crosbyman
Posts: 801
Joined: Tue Mar 10, 2015 11:39 pm
Location: Montreal Canada

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby crosbyman » Mon Jan 22, 2018 4:21 pm

thanks... saw that article in the Johnson maintenance bible... i'll measure my tn27 shaft and drill the impeller out

thanks

User avatar
Mumbles
CYBER SHERIFF
Posts: 3563
Joined: Mon Mar 09, 2015 3:42 pm
Location: Victoria BC

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby Mumbles » Mon Jan 22, 2018 4:37 pm

FrankR wrote:
Slight typo there I think. The TN shafts are larger, not smaller than the 3, 5.5, 7.5. So, bore the impeller out to fit a TN-xx.[/size]


Slight typo is right! I was just checking to see if everyone was on their toes this morning and you certainly were! Thanks for catching that! :oops:
Still searching for a rudder and hardware to fit a KOBAN. ☺

Member of the http://uppercanadachapteroftheaomci.yolasite.com/

FrankR
Posts: 3011
Joined: Tue Mar 10, 2015 6:32 pm
Location: Florida

Re: tn27 impeller 375688 now sierra 18-3001 ??

Postby FrankR » Mon Jan 22, 2018 4:45 pm

All TN's are same size. I'm thinking the shaft is 0.437" but could be wrong. Now I gotta go out and measure one. A few years ago, I tooled up to bore those things to sell, but discovered that another club member was already doing it. So I didn't go into competition with him. Now I don't remember who it was.


Return to “Ask A Member”

Who is online

Users browsing this forum: PCurry077 and 9 guests