1974 Mercury 110 9.8 Not Sucking Water

[GreenWeenieWizard]

I'm in a pickle. The motor I have above is paired with a 1989 BassTracker. The BT has a 19.5" transom, and the motor supposedly has a 20" driveshaft. Problem is the cavitation unit sits about 1.5" above the bottom of the boat.

Runs great until I get on plane. After that, the engine shuts off after a bit. It can't be getting water.

Has a two bladed prop.

Would a three bladed prop assist in getting water through the system? Would a newer outboard make up the 1.5" difference?

I even ordered a 20" housing, driveshaft, and gear selector for a 20" setup. After receiving them, I saw that they were the exact same things I already have.

Just got the boat and motor as a package. The previous owner still had the receipts of all the work put into the motor to get it running right. Does great in the barrel.

Thanks for any help!

 

[racerone]

Any pictures ??-----Have you replaced the impeller ?-------Looked at the washer on top of the water tube under the power head ?

 

[GA_Boater]

Welcome aboard.

You can put a 28 bladed prop on and it won't help pumping cooling water.

Do you have a jack plate? And did the work show the impeller has been replaced?

Before looking at a new motor, can you post some photos from the side showing the motor tilted down.

 

[GreenWeenieWizard]

I will take some photos tomorrow in the daylight.

I do have a new impeller to try just in case the one on it is bad.

I do not have a jack plate.

I have not looked at the washer, either. I've yet to tear into the motor thoroughly.

Thanks for the heads up on what to look for.

 

[tpenfield]

Sounds like you potentially have a few things going on . . . transom may not be the right high for engine (or vice versa) and maybe impeller is not up to the task (wearing out). As the others have said, a few pictures of how the engines is relative to the transom and hull bottom would help.

 

[GreenWeenieWizard]

Let me know if you can't see the photos.

Thanks!

 

[racerone]

Just another case of a short shaft motor 15" on a long shaft boat.----Who did you order the 20" parts from ??-----Just another classic mistake I think.

 

[merc850]

The water pickup is that stainless steel plate on the bottom of the anti-cavitation plate your motor is way too high water must be on or covering the plate. If you ran it out of the water the impeller and possibly the pump have been damaged, not to mention overheating the motor.

 

[tpenfield]

Just another case of a short shaft motor 15" on a long shaft boat.----Who did you order the 20" parts from ??-----Just another classic mistake I think.

+1 short shaft motor . . . on a long shaft transom.

 

[GreenWeenieWizard]

When measuring the driveshaft housing, it measures out to 20".

All the parts I received on eBay were from Marine Sellers that listed the items as 20" compatible.

Was I measuring wrong? I measure the entire driveshaft housing. Should I only measure from where the cowl ends to the cavitation?

I just assumed that the clamps were made a bit differently since it is an older outboard.

New to the game of working on outboards, so I greatly appreciate everybody's advice.

 

[flyingscott]

You measure from the part of the transom clamp that sits on the transom to the cavitation plate. The measurement will be about 18" for a short shaft and 22" for a long shaft

 

[racerone]

You have a 15" transom motor !---And some sellers simply do not know a lot of the facts on outboard motors.---Yes , you measured wrong !

 

[GreenWeenieWizard]

Well, thanks for the advice. Apparently I'm a dingleberry.

Like I said, just a newbie in this. When looking up stuff before for other things with my boats, this site has been excellent.

Thanks again! I'm sure I'll be bugging you guys more.