Tohatsu breaker points

[Bosunsmate]

I pulled my outboard out today to get it ready for spring and it didnt start. I figured id clean the breaker points but i ended up squashing the whole breaker point part beyond repair with the flywheel bolts. When i tried to re-straighten it the little pole it swivels on broke off along with the bit that drags along the inner flywheel to open the points
Its a Tohatsu M3.5A
These points seem to be NLA
Any tips regarding replacements?
They have a three diamond mitsubishi sign on them. I think ive linked it to being in tohatsu motors up to 2005
Thanks

 

[pvanv]

Tohatsu has not used points in over 20 years, the points are NLA from Tohatsu. Not sure what parts houses you have in NZ, but in the States, you might get lucky by taking your damaged debris to a NAPA store or other olde tyme parts house to see if you can match up something from a different application.

 

[Bosunsmate]

Thanks for the tip PVANU
I will try a few parts places and see what i can find. I live in the country so unfortunately it may be a while.
Also ive read since that Mercury may of being involved with this motor and the points on their 3.5 look very similar if not the same- hard to tell from photos since they arent in my hand. Their schematic for the motor looks exactly the same too albeit with fins on the flywheel.
Those points seem to still be available- however very expensive. That find led me to other points made by Yamaha and also Mariner which look identical too.
These similar looking points are on the Merc mariner 3.5- 2.5 and yamaha P models or something a rather.
http://www.buitenboord.com/dk/yamaha-utenbordsmotor-contact-breaker-assy-p65-p95-p-15.html
http://www.southcentraloutboards.com...-80181m-nc0917

So hopefully i do get a match.
Il post back what i eventually find out

 

[Bosunsmate]

Ive got some points, not the same that were in there but very close, they are daiichi points.
The three diamonds was daiichi, not mitsubishi.
Hoping to put it back together tomorrow.
Just wondering what the flywheel torque and points gap should be and any other tips?
Looks like the cam lobe that opens the point is on the flywheel, so i suppose i will need to adjust the gap through the big holes in the roof of the flywheel

 

[Bosunsmate]

Also do i grease the rubbing block or just lightly oil the wicking pad?

 

[pvanv]

If your points have a wick, you can use points cam lube (light, high-temp grease) on the wick.

 

[Bosunsmate]

thanks, it has a wick so il look out some light High temp grease,
any tip on the flywheel torque or points gap?
im picking its probably around 50 foot pounds?

 

[Bosunsmate]

Well i put some light grease on.
I had to modify the bolt hole on the points a bit with a drill as i couldnt get the tightening screw right through it.
I set the points at 0.14" or 0.36mm for those of us who use metric
I tightened the flywheel to about 40 foot pounds and she started after a couple of pulls.
However i noticed that the Pisser tube wasnt working but there was some stream out the holes at the bottom of the leg.
i felt the head and it was heating up far too fast and kept on going

 

[Bosunsmate]

I tried blowing down the pisser but got no joy.
I decided to pull the head, luckily the four bolts came out very easy
Here is what i saw,
Well i cant seem to upload a photo. But the head and cylinder jacket was just full of salt. Half a cup at least. No way this kicker would of got my 14foot fibreglass main boat home if i needed it too, which was its brief.
I then put her in a tank and pulled her handle a few times to check water was entering fine through the lower inlet port into the cylinder jacket.
I also poured water down the very rear hole on the crankcase (its right at the headgasket surface, the fifth hole there that isnt part of the four headbolts) to check that the exit of the water to the exhaust there is not blocked too.
After i had cleaned out all of the cylinder jacket i then scrubbed the mating faces and since moneys tight i reused the old head gasket, i put some gasket sealant around the mating faces, keeping well clear of the fire-ring and then after putting a dab of oil on the clean threads i tightened the head back on.

By the way mine looks almost exactly the same as this 2004 model apart from different decal
https://www.youtube.com/watch?v=TUkOjWjHix0

 

[Bosunsmate]

The fire-ring on the headgasket hardly seemed compressed at all so i thought i could give it another go.

I also ended up cutting the outlet T for the pisser. I cut it at the right angle so icould then put some wires straight down and into the waterjacket. After doing that it was very clear. I then used a zip tie just to be sure it would stay in place on the slightly shorter plastic outlet. The pisser hose bent easily down to the leg even without the use of the right angle T

Il run it tomorrow and report back.
This motor seems to be like all the late 90s model yamahas ive had too so i suppose what i found with the salt crystals is applicable to most of these small motors. Seems like on the bigger motors there is more waterflow or more surface area to dissipate the heat or something but what i found was a gigantic amount yet it had still got my dingy around on a couple of short trips last season but it must of being getting near BOING heat levels.

The other thing i found interesting was that the piston had an arrow on it pointing down. Its a looper but in all other motors ive worked on the arrow has being facing up.
If it was installed the wrong way i would expect it to run really bad and not get a 75 kg guy and a ten foot dingy up on a plane.
Maybe someone whos changed a piston on these can enlighten any listeners on that.

Anyway hope this helps anyone with one of these motors/ or something similar.
By the way the points i got were for a suzuki GT380 which needs one of two different points (they are very different, the one i got had OEM 33170-31010
The points were Daiichi (Japan) DN44R/L
The interesting thing was the flywheel had a Daiichi symbol on it too

 

[pvanv]

We don't usually re-use head gaskets; I can only hope it works for you.
That block does not run especially hot, but apparently your PO didn't flush it.
The arrow is to align the piston to reduce slap. Actually, it might run stronger pointed backwards, but won't last as long. My parts book doesn't specify arrow direction, but I would also expect the arrow to point up.

 

[Bosunsmate]

We don't usually re-use head gaskets; I can only hope it works for you.
That block does not run especially hot, but apparently your PO didn't flush it.
The arrow is to align the piston to reduce slap. Actually, it might run stronger pointed backwards, but won't last as long. My parts book doesn't specify arrow direction, but I would also expect the arrow to point up.

Yes i wouldnt be surprised if the PO never flushed it. When i went to pick it up he said il start it to show you it works, i said thats not necessary, thinking he would go get a bucket and fill it with water. He to my horror amazement just turned the fuel tap then pulled the starter cord and stood there reving it up right on the dry pavement.
Interesting about piston slap but actually running stronger as it does seem quite powerful as much so as my last yamaha 4, bit of a concern though as its not good having a dodgy safety kicker back up
cheers

 

[Bosunsmate]

No Title

Well put it back in my water bin and it fired up well so im glad the headgasket behaved and saved me a few dollars and rural postage.
The pisser stream was solid, right from low idle up to fast revs where its pushing out even stronger. Ive read online that these things often dribble out, thats what mine use to do, id say that a dribble means you have a problem somewhere and it might be best to chop that T like i did and poke a wire in the hole in there for starters.
I retorqued the head and noticed the sparkplugs im running are ngkbr6hs whereas the sticker on the inner bottom cowling says NGKB8HS10 or Champion L8C
Not sure if its worth changing since its running good......

I ran it dry and its now drying in the spring sun before i put her into storage in the bow of my runabout/speedboat, hoping keeping her tied down and contained there will minimise the porposing i get and keep her out of salts way.

 

[pvanv]

I believe your sticker is either from a different motor, or is damaged some way. My documentation (for the model with electronic ignition -- not points) shows that the M3.5A should run the NGK BP6HS for the States or BPR6HS (with resistor) for Canada. The #8 plug would be 2 steps colder, and would foul faster.

 

[Sea Rider]

On 3.5 engines arrow must point to exhaust port, all other portable models points to flywheeel. All 3.5 runs on number 6 heat range plug. If piston is badly assembled will have balance issues. There's 150C° temp difference per each +,- heat number.

Happy Boating

 

[Bosunsmate]

No Title

ok thanks, il remove the sticker and happily stick with current plug.
I cant quite recall where exhaust port was.
It definitely wouldnt be at top of the cylinder.
If exhaust port was at bottom of cylinder then great its correct.
If exhaust port is on port side then piston would be incorrect as itd be wrong by a 90deg turn, but thinking about it i dont think a piston could be installed 90deg in the wrong direction as the connecting rod big end would be on the wrong angle to connect to crankshaft.....

 

[Sea Rider]

If powerhead is already out of engine pan, turn block upside down and check exhaust, the dirtiest, most carbon up port, that's exhaust. You can assembly that piston with arrow pointing intake or exhaust port. This issue happened to me, luckily the error was inmediately corrected, have not tried running a 3.5 with piston assembled backwards though to see what happens.

Intake, exhaust ports are usually located sideways of cylinder, not up or down.

Happy Boating

 

[Bosunsmate]

If powerhead is already out of engine pan, turn block upside down and check exhaust, the dirtiest, most carbon up port, that's exhaust. You can assembly that piston with arrow pointing intake or exhaust port. This issue happened to me, luckily the error was inmediately corrected, have not tried running a 3.5 with piston assembled backwards though to see what happens.

Intake, exhaust ports are usually located sideways of cylinder, not up or down.

Happy Boating

Ok thanks, ive got her sealed up in a drum in the woods at my place ready for use, so i might just leave it as she has being for the past year or so ive owned it but il post back if i do undo it