Query on Tohatsu 3.5hp water cooling

[KeironF]

Does anyone know where the impellor is on a Tohatus 3.5 2 stroke. Cooling failed at the weekend and I suspect it's the impellor. Do I need to strip the gearbox off or is it behind the prop. The former I supect but just wanted to check.

Cheers Keiron

 

[Lakesailor]

It's behind the prop. Well mine is anyway, but it's rather old. Take off the prop and undo the plate behind (2 screws) It's behind that.

 

[SK700]

Hope I not telling you how to suck eggs.

Are you sure cooling has failed, the tell tails do get blocked quite easily. A quick poke up the hole with a wd40 tube might be enough to free any debris.

 

[KeironF]

Hi SK700. I think it's definetly the cooling there was no telltale and a bit of steam. Luckily the engine didn't seize so it should hopefully be OK I only ran it for a few minute before I noticed. I must admit the telltale has always been poor on the engine even though it's only 3 years old.

Cheers Keiron

 

[kirielad]

How old is your engine?

On my 2006 3.5 the impellor sits above the gearbox in the lower half of the leg. There are (from memory) 4 upwards facing bolts which need to be removed, as well as the in gear/neutral linkage.

 

[gandy]

[ QUOTE ]
It's behind the prop. Well mine is anyway, but it's rather old. Take off the prop and undo the plate behind (2 screws) It's behind that.

[/ QUOTE ]That's where it is on my Merc 2.2 which has no gear shift so the prop drives all the time. If the engine has a F-N selector then the impeller is in the leg somewhere before the gear shift.

 

[Lakesailor]

That'll be right. I don't have a gearshift. It's so old that Wills Marine can't establish if it's 2 or 3.5 HP as on old ones there were no serial numbers or gears. /forums/images/graemlins/shocked.gif

 

[achwilan]

You'll find your Tohatsu parts list with drawings here:
http://www.bateaushop.com/tohatsu/piece_detachee/2_temps.html
I have a Tohatsu 3,5 too: water pump is not behind the screw, but above in the gear case

 

[Moonshiners]

if it's not got F-N-R then as above it should be behind the prop, 2 bolts, nice and easy!

 

[kirielad]

[ QUOTE ]
if it's not got F-N-R then as above it should be behind the prop, 2 bolts, nice and easy!

[/ QUOTE ]

If its a 3.5 Tohatsu (and not a 2.2) then it does not have F-N-R just Neutral and Forward.

The pump is above the gearbox case, in the the lower half of the leg.

 

[dod]

May issue of PBO has a guide on where the pump is and instruction on removal of lower leg to change impeller.
I have same model and user manual does not give any info. Good luck.

 

[davidpbo]

Downloadable manuals here here

There was no water out of the tell tale when I first got my 3.5 due to salt blockage but engine ran cool. Most of the cooling water goes down the leg I think. In my case a piece of wire up the tell tale hole would have cleared it. If yours is overheating more drastic action may be required.

 

[gandy]

Unfortunately those are only the operators manual, and don't cover all the servicing operations, especially those that involve dismantling.

 

[Topcat47]

Just a thought, the 3.5 does not have reverse gear, you rotate the whole engine. It does have a dog clutch though, unlike the 2.5.

 

[davidpbo]

Apologies did not look at them in detail I thought I had downloaded a maintanance manual in the past. I must have stripped mine down without a manual.

 

[Lakesailor]

To everyone, not particularly Topcat.

Goodness me. It's not difficult.
Take off the prop and the plate behind it. 5 minutes.
If it's not there it's up the leg.

 

[KeironF]

Many thanks for all your advice. The impellor looks fine so it's probably a blockage somewhere.
Cheers Keiron