Tohatsu 3.5A2 fuel line issues

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Hello,

Tag 3.5 A2

I picked up a 13ft aluminum boat and it came with this mounted to the back, I took it off to fix the transom and decided to look at it today

No numbers on engine anywhere, id with decals and the Tohatsu website


1)Good bright spark
2)Plug looked good
3)Cylinder looking through plug hole looked good
4)good compression (no gage just felt good with throttle closed and plug in)

It turns over so my reason for the thread

The fuel line is a "stepped" rubber fuel line with a small and big end (which is cracked and not long enough or pliable to cut back)

20170622_150009_zpsz0ta5itt.jpg


it needs to be replaced, where to buy?

The small end goes to the vacuum fuel pump?

20170622_143608_zpssb7bdces.jpg


and gas tank on back side

What fits here, beside the line going to carb?

20170622_145957_zpsrvz9kk16.jpg


Also this is not connected to anything and it looks like it has been cut

20170622_150016_zpsl1ro4kzb.jpg


I haven't had luck finding pictures online
 
Last edited:

pvanv

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Apr 20, 2008
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The M3.5A was originally designed for gravity feed fuel to the carb. That clear fuel line must go, it hardens and is unsafe when used with gasoline. Your motor has been setup to use an external fuel tank in addition to the internal tank (not typically necessary, since they use so little fuel). That device on the side of the motor is not a regulator, it's a vacuum-operated fuel pump. The connector below the pump is where the external tank used to connect. The hose on the front of the motor is the vacuum pulse to the pump. You can take all that stuff off the motor (cap or plug the front vacuum port), get new fuel line from any dealer, and you can just run on gravity feed. You may also want a new internal fuel tank, which is shaped and mounts quite differently than the one on your motor, and uses a fuel shutoff **** with strainer..

Based on age and appearance, you will also probably want a new water impeller, which is located on the prop shaft between the prop and the LU gears.
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Thank you, i will grab some new line today

And if she runs i will change out impeller for cooling
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Sorry for picture quality, the sun on white panels was not friendly

I replaced the lines per current setup to see if she fires up, THANK YOU PAUL!!!!!
20170623_173353_zpsq28rr6uv.jpg

I didnt replace the clear line yet, nothing in stock in the mountains of TN.

I had nothing coming out of carb, took it apart and main jet and needle valve was gunked with a white glue like stuff, cleaned and put back together
20170623_152400_zpsnmdilwfw.jpg


20170623_152414_zpsirrhxz0i.jpg


20170623_152418_zpsaovjdbnu.jpg


next was starting her, little bit of gas in carb and she sputtered, pulled a few moar times with choke on and flooded the ole girl

so remembering the 80's and youth, I pulled plug, left choke open and throttle open and dried her out

put plug back in, 1 pull with choke one and then back to open, she fired right up, I guess 85* doesnt really need a choke

she sat idling like an old dirt bike or 3 wheeler!!!!

Throttle response was VERY crisp!

Put into a tank I cut off today and......where is the tell tale water supposed to come from? I guess the passages and impeller need replacing any ways

20170623_174711_zpsdduuvfw3.jpg


water depth was above the only holes I could find on lower unit

20170623_174842_zpsglhwe72b.jpg


I kept my hand on the head/cylinder the whole time to not overheat

THIS HOSE had air coming out of it? is this a engine vent? or the tell tale with no impeller to shove water through

20170623_174734_zps5xjfffeo.jpg


Thank you!!
 

pvanv

Admiral
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Apr 20, 2008
Messages
6,500
Unless that tank requires the fuel pump, you could route the hose from the carb right to the tank, eliminating the fuel pump, but then you would need the fuel **** of the newer style tank. That hose that is blowing air is the telltale. Clearly you are not pumping water. Depending on condition, you may also need the pump case and gear case head; there isn't any stainless liner or wear plate for the pump, so those aluminum parts can wear, and cause too much side clearance at the impeller. Fuel mix is 50:1.
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Cool thanks, will pull apart and check pcs

50:1 check! same as chain saws, no ethanol also

Will pull lower today
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Tore down tonight, there is a reason monkey's shouldn't play with anything other than bananas

It doesn't matter if it is car/house or boat related

So i pulled out the prop cotter key, removed prop and the key fell out (1/2 inch long nail with head still on it)

I shook my head, went to loosen 2 bolts, yup, lower one, tab is broken off
Pulled cover, the impeller (it was whole just a couple dry rotted broken vanes)
Pulled it and drive pin
Next was impeller housing..
Guess what?
Lower tab broken off

Here are parts and best is yet to come!!!


20170626_185315_zpswoauzptj.jpg


Flipped over, see shiny ring where prop rubbed?

20170626_185322_zpsxvyhu9a2.jpg


The cause for wear mark?

The monkey got out of the trunk! And grabbed wrenches...errrr

No wonder it leaked water and wouldn't pump yo cool motor....
20170626_190102_zpsvby73yqf.jpg


You think they over tightened the bolts?
This is...
Why people get paid to work on stuff

So i need housing, bearing, seal, impeller and cover

Best place to get part?

Biggest problem is how bad was this overheated?
 

pvanv

Admiral
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Any dealer for parts.
If compression is still good, you probably survived any overheat.
 
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TGuy

Petty Officer 1st Class
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Mar 17, 2005
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217
doubt a monkey would screw it up that bad. Most likely reason is in the headlines of the newspaper you have your parts on..."Suffering from the opioid abuse of others". :)
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
doubt a monkey would screw it up that bad. Most likely reason is in the headlines of the newspaper you have your parts on..."Suffering from the opioid abuse of others". :)
Actually....you are partially correct ;)
 

pvanv

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Parts are available, but not as cheap as you might think. Will cost over $50 for the castings, bearings, seal, and o-ring.
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
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Checked compression a couple times last night

Choke open
Throttle open
Dry, except for residual fuel

3 pulls each to reach max# 30, 70, 90#

Repeated test 3 times, same results 90# max

Small 2 stroke, rope pull, this should be okay, correct?

Whatcha think?
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
Thank you!

Well photobucket has done a number to the interwebz, I was going to do a thread here, but I can't host pictures :mad:
 

bansil

Petty Officer 2nd Class
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Oct 27, 2016
Messages
115
THANK YOU!!!! off to read tutorials
 
Last edited:

pvanv

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Will need your email address, also shipping name/address. Please PM that.
 
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