Nissan NS5B-Can't get the darn thing in...

[Carl V]

Hi guys...I just replaced the water pump on a NS5B and all went smoothly, but trying to get the lower unit back into the motor has been impossible..the shaft goes in up to the spline receiver in the head but then stops dead...it's not the linkage or the water tube stopping it but seems almost like the shaft is to big for the receiver, which of course it is not..I have also tried turning the shaft to maybe seat it but it just won't go...and also put light oil on the splines but still no good.......and yes I do have the manual but it does not address the problem. Any suggestions ????

 

[pvanv]

Re: Nissan NS5B-Can't get the darn thing in...

That requires some finesse. Sometimes they "fall" into place, other times, it's a patience-testing installation. Explains why marine mechanics charge up to $100 an hour.

As an alternative, you can pull the powerhead off, seat the LU, and reinstall the head. If so, use a new base gasket.

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

There's got to be another alternative to removing the power head.... I've asked for similar help with my Tohatsu on another thread, but just in case someone only see's this thread..

Any Takers...

I've done this same re-fit on a 72 Chrysler 10Hp and a 84ish Mercury 9.9 and moving the flywheel a little always solved it. The splines on the shaft were straight, but on the Tohatsu they are curved.

Any Help or suggestions would be great....

Thanks,

Kev

 

[joebob14]

Re: Nissan NS5B-Can't get the darn thing in...

Have you tried having a buddy rotate the prop while you slide it back together?

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Thanks Joe,

I have tried to rotate the prop in Gear while trying to re-seat the drive shaft and again no luck. I'm sure there is someone out there with a tip for this one

Kev

 

[TOHATSU GURU]

Re: Nissan NS5B-Can't get the darn thing in...

It's not a tip thing....It's a feel thing. It literally goes in just like you think it does. Experience with doing it and feeling the differences in pressure as you maneuver the shift rod and drive shaft are the only secret....And sometimes even then its a PIA. IE Two engines, same model, same tech:

Engine one: 30 seconds

Engine two: 10 minutes

No difference between the two except in the mind of the tech.

I have seen more than one experienced tech give up and call over the shop flunky to do one...And watch that flunky get it right in.

So, patience, patience patience..

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Thanks very much for the advice Guru... I read it in work today and returned home this evening full of fresh in-vigor to get this thing sorted......

I've just poured myself a Whiskey nothing worked. Tried rotating the prop in both directions while putting it under some pressure to push together....Nothing....

I tried to get the feel of it, tease it, guide it..... Man I'm pi$$ed

I can't believe such a simple job is such a pain in the *****.... Any fresh ideas ?

All this before I even get my problem sorted.

 

[TOHATSU GURU]

Re: Nissan NS5B-Can't get the darn thing in...

Honestly, it's just a feel to it. You either have the rhythm and the luck or you don't. Keep trying and it will eventually go in....This is a prime example as to why a tech charges for an hour on a ten minute job

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Thanks Guru... I appreciate the help. Just getting a second Whiskey to calm the brain a little before I hit the bed. I will try again tomorrow.

Hopefully I'll get this sorted, so I can actually go about the repair.

I'll start a new thread and hopefully you'll get the time to throw some advice in there.

Much appreciated,

Kevin

 

[pvanv]

Re: Nissan NS5B-Can't get the darn thing in...

I have personally scratched my head on this job (regardless of brand of OB, BTW), then dropped the project for another job, returned to the LU install later, and it just slid into place. TG is really completely correct... sometimes you just need the right touch... and sometimes you just don't have the right touch (at that time).

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Man ohh Man, I have never in my life thought this would be such a Pain.... I tried again this evening to try get this to slide together, and nothing.... I was in the garage for another 3 hours. I think I will have to drop this one off for repair, but this kills me as I have always been handy enough around the smaller outboards and have never had to leave one in for repair. I've even done a couple of head gaskets, so I'm not a douche..... Also, a "Tohatsu" guy will be hard to find in Ireland and I want to make sure this is done correctly

A couple of questions before I give it one more go tomorrow.

I am wondering if the drive shaft separated correctly. When looking at the parts Manual it seems that the splines on the drive shaft that enter the power head are straight. On my engine, 2006 Tohatsu MFS5BS the splines are curved and I think this is what is causing the problem. I removed the drive shaft from the gear housing and noticed that the splines are indeed straight.... I am 99% sure that the power head end is curved and the gear housing end is straight as I found it ,,,, but is it possible that the drive shaft did not separate correctly???

Hopefully one of you guys has done this engine type recently and can give me a description of what worked for you..... I think that would help a lot if you have the time. From what I can feel if the shaft rotates anti clockwise (prop clockwise) and the flywheel clockwise with enough pressure these should just slide together..... Sounds simple, but from what I feel the drive shaft does not even seem to be grinding against the head unit. Sorry for all the text, I have misplaced the digital camera. I will try take a few pics tomorrow.

Thanks again for the help guys

 

[pvanv]

Re: Nissan NS5B-Can't get the darn thing in...

Ugh. You have a twisted driveshaft. Someone hit the bottom, and hard. The splines are supposed to be straight. I doubt you will ever get it back together as is. Even if you did, its life expectancy would be in question. You will need to specify long or short shaft to order the correct part number.

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Paul,

You are 100% correct.... I pinged the Prop of a Rock while fishing in a river. The Trust Washer was shot so I thought that every thing was in order. The curved splines did throw me off. I will post a pic tomorrow, the are perfectly bent. It honestly looks like it was made that way. Do you happen to know of a online store that might ship to Ireland?

Also do you think that the splines in the power head will be ok, or will I need to have a look?

Many thanks guys, Looks like this will be a costly one.

Kev

 

[pvanv]

Re: Nissan NS5B-Can't get the darn thing in...

Many dealers will ship overseas. Your UK dealer is
TOHATSU MARINE, LTD.
PORTMORE, LYMINGTON
S041 5RF, HAMPSHIRE, U.K.
44-1590-670787 (TEL)
44-1590-670520 (FAX)
Email: sales@tohatsu-uk.net

If you need a US dealer, you can email paul@obersheimersails.com or any other US Tohatsu dealer that ships internationally. You will need to specify Short, Long, or Ultra Long length.

US Prices are as follows:
369643010M DRIVE SHAFT S $110.57
369643020M DRIVE SHAFT L $116.40
369643030M DRIVE SHAFT UL $128.02

 

[Kev_03]

Re: Nissan NS5B-Can't get the darn thing in...

Thanks very much Paul,

Any thoughts regarding the fitting in the power head? Is it also likely to be bent?

I will go about getting the part ordered.

iboats to the rescue again

I owe yourself a TG a beer.

Thanks guys,

Kevin

 

[pvanv]

Re: Nissan NS5B-Can't get the darn thing in...

The crankshaft splines could possibly be bent, but unlikely. And pricey. This motor has a pressed-together crankshaft, which comes complete with connecting rod and bearing. US price 369000300M CRANK SHAFT ASSY $265.70. Significant labor to change it, as you have to tear down the powerhead.

Whoops. I missed the fact that there are two threads for two different motors going on at once here. Those part numbers and prices are for the NS5B 2-stroke. Reading this back, it appears that you have an MFS5B short 4-stroke. Different crankshaft part number.
3H6000300M CRANKSHAFT ASSY $154.38.
Same driveshaft part numbers.