Tohatsu 25 Crank

[haddon]

I need to know of a good place to get a crank shaft reworked.
Or if there is anyway to do it yourself.
Also any reason a c25 would burn the main bearings.

This will be the third time i am going into this motor.
First the main bearing came apart.
I replaced the crank with a used one.
Next lost compression on bottom the rings had stuck and piston galled the wall
so i replaced with a used block and new pistons and rings.
Then 2 weeks later used crank has went out but i thought it was weak but its all i had to work with now 2 weeks means 2 to 3 hours a day for 2 weeks.

 

[Sea Rider]

Re: Tohatsu 25 Crank

The crank shaft comes in peaces, so any part can be replaced standard new, will need a press to open & close shaft, a machine shop can do it, will need to send crank case, new parts and factory specs to press close crank shaft and check sideway tolerances, don't know if this applies to all models as you are not specifying model.

Issues could be : crank case lube obstruction, clogged lube hose, poor general lubrication, by main bearings you mean top & bottom or middle ones ?

Happy Boating

 

[haddon]

Re: Tohatsu 25 Crank

middle ones
and lube tubes you mean the plastic ones on the side of the block ??

 

[Sea Rider]

Re: Tohatsu 25 Crank

middle ones
and lube tubes you mean the plastic ones on the side of the block ??

Yes side of block, has a small check valve inside. Is the middle bearing original one, the one with tiny pin that secures on crank case ?

 

[haddon]

Re: Tohatsu 25 Crank

yeah they are all orginal bearings on the cranks with the pins

 

[Sea Rider]

Re: Tohatsu 25 Crank

yeah they are all orginal bearings on the cranks with the pins

If you have changed them, prob crank case & crank shaft out of tech lateral tolerances or maybe poor lubrication from case & lube hose. Have you had issues with crank pin also, or just ball bearings ?

Happy Boating

 

[haddon]

Re: Tohatsu 25 Crank

by crank pin
You mean the little pin on the side of the bearing that rest on the block face??
those pins seem fine and the cranks were original from tohatsu the first one was the one that came from the factory in the motor.

The first crank the middle bearing the balls seemed to explode. There is only really one real bearing in the middle the other one is like a aluminum bearing shaped disc i am sure it has some sort of bearing inside but it does not look like a normal ball bearing like the rest of them.

The big queston is where can i get the crank fixed i mean 1000 buck for a new one is out of the question. Can i send it some where we dont mind spending money on it just need to be within reason. We paid over 200 buck for the used one. Now i have not broke it down again to see how the used one came apart but i know from the feel that its the bearing again or at least one of them would be nice if it was top or bottom one i know i could replace them but i would rather have all new bearings.

I even thought about pressing one apart my self i mean i got 2 so if i screw up it would just be for fun.

 

[Sea Rider]

Re: Tohatsu 25 Crank

The crank pin is the cylindrical part on which the needle bearing of the connecting rods rests inside, yes there is one and only middle ball bearing, next to it a round part called labyrinth packing (still don't know what is for).

Being all of us on the forums to help, would be a good idea to count with someone skilled to do the job, surely a good samarithan will appear, maybe Paul or TG can recommend someone or do the work for themselves if happens that parties don't live at extreme distances one from another.

Happy Boating

 

[haddon]

Re: Tohatsu 25 Crank

yeah i was hoping someone would know of a shop i could mail it off to or something

Does the crank have splines or is it smooth I had read that some are smooth but i cant see how i would stay in time without spines

any help is appercitated

 

[TOHATSU GURU]

Re: Tohatsu 25 Crank

There is a place in either South or North Carolina called Ackermans...Or something like that, but you need to re-evaluate your project based on what you haven't been able to do so far. These cranks do not have issues so you need to determine why you are having problems, before you put the engine back together again.

 

[haddon]

Re: Tohatsu 25 Crank

All I can think of is that tube.
the first crank I just chocked up to the motor being old i mean we rain it for like 10 years as a commerical motor quit the business then used it once or twice a year the next 10 just to pole fish then this year dad started back the crank had a lot of use. The next problem was galding the piston i think that was the the used cranks problem the lower tie rod had a lot of wiggle. I had my dad take it back to the guy we bought it from to see what he thought its a tohatsu dealer. Dad said he thought it was ok but i am not sure if dad asked him and the dealer is over a hour away. I then put it back to gather with the used crank again hoping it would last maybe a year. Then the coil pack we bought in spring went out so how while i had it took apart so it then went back to the dealer who put the new coil pack on. He did tell dad that it had a bearing rattle but that is normal on old cranks.

So to sum up
this is what i think.
Original crank just crapped out from age.

Used crank has to much side movement in the lower tie rod which caused the rings to stick which caused the galding.

Used block the Dealer sold us most likely had a stopped tube which then kill the bearing in the used Crank.

And it looks like every part i have got from that dealer has been crap including the new coil we bought in spring.

Plus side dad is going to look at a 1992 boat and 1992 evenruide 25 all for 1000 bucks if it runs good its coming home, but i still need to get this motor back running i really loved it was as fast as a 40 would run like nothing else.

 

[TOHATSU GURU]

Re: Tohatsu 25 Crank

My best advice is to look for a good used engine and use the current one as a spare parts source.