6 hp Nissan four stroke valve adjustment - how to?

[fishon71]

I have a 2007 Nissan NSF6BS 6hp four stroke - the lock nuts backed off the lower valve adjuster and fell off and the main nut backed off stopping the engine - can some one tell me the valve adjustment clearance and procedure? Should be pretty easy on a one cylinder.

 

[pvanv]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Unusual problem. Locknut may not have been locked down correctly. Valve clearance is set with a long feeler gauge (preferably the ones with the 45-degree bend in them so they fit in the area well), when the motor is cool, and piston is at TDC. Full procedure is in the Factory service manual, available from any dealer, including me.

 

[fishon71]

Re: 6 hp Nissan four stroke valve adjustment - how to?

That was useful information

 

[jrs_diesel]

Re: 6 hp Nissan four stroke valve adjustment - how to?

fishon71,

Here is a link to an article I wrote on setting the valves on a 6 cylinder diesel. While the engine is different, the procedures are very similar. Base on the parts diagrams, yours should be easier than my multi cylinder, multi valve beast of a diesel engine. I know I'll eventually have to do this to my 6HP Mercury (Tohatsu) outboard eventually as well.

I also had a locknut back off and let go while going down the road on my #5 cylinder, exhaust valves. That was self inflicted by me not tightening it all the way. Made a really odd thumping noise when it let go. Luckily I didn't bend a push rod, and I was able to re-assemble on the side of the road, and get home. Later that week I went through all the valves when the engine was cold and reset them.

http://www.dieseltruckresource.com/...aq&nr=169&catnr=7&prog=1&lang=en&onlynewfaq=1

The only other thing you need is the valve lash specifications for the intake and exhaust.

Good luck

 

[fishon71]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Well, it is super easy on a one cyl to figure out - I just put the piston at top dead center and measured the intake lash at .006 and adjusted the exhaust at the same. The motor runs fine but I wish I knew the correct numbers, I don't plan to buy a manual.

 

[TOHATSU GURU]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Did you think about contacting Nissan at 972-323-6003 and just simply asking them?

 

[jrs_diesel]

Re: 6 hp Nissan four stroke valve adjustment - how to?

You should loosen the exhaust up a bit.

On my diesel the exhaust setting is double that of the intake. My intake valve lash is set to .010 inch, and the exhaust is .020 inch. My understanding is that the exhaust valve(s) have to deal with more heat, and the larger cold gap will compensate as it warms up. If too tight, the valve could be held open slightly, losing a bit of compression, power, and efficiency. You also risk burning the valve and valve seat.

I just looked at my Mercury (Tohatsu) 6HP, and the sticker on the the front (forward) side of the block has the valve settings on it. the intake is .06mm, and the exhaust is .011mm.

 

[pvanv]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Well, it is super easy on a one cyl to figure out - I just put the piston at top dead center and measured the intake lash at .006 and adjusted the exhaust at the same. The motor runs fine but I wish I knew the correct numbers, I don't plan to buy a manual.

You should definitely consider buying a Factory service manual. Working without one is driving blind. The small expenditure is money well spent.

 

[fishon71]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Paul,

If this was my motor I would buy a book but I work on every outboard out there and can't buy books for all of them - pretty simple question I thought this forum could be more helpful than telling me to buy a manual.

 

[pvanv]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Paul,

If this was my motor I would buy a book but I work on every outboard out there and can't buy books for all of them - pretty simple question I thought this forum could be more helpful than telling me to buy a manual.

Seriously? Our shop has a service manual for every model we work on. Of course, we also send our staff to the manufacturer's school, so they are up on the techniques for the newer models.

Page 25 of the manual, Part # 003-21034-1, which covers 4A2, 5A2 & 6A2 4-stroke models, List Price (MSRP): $26.52 (You should get dealer pricing, so less to you, right?)... gives valve lash specs at 0.06-0.14mm intake, and 0.11-0.19mm exhaust.

 

[TOHATSU GURU]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Paul and I both ascribe to the same theory that everyone who touches an outboard needs to have a service manual in front of them. It's not that we don't want to help...It's about helping people who will put some effort into helping themselves first. It's like the old "Give a man a fish and he eats for a day", Teach a man to fish and he eats till the government puts in a catch limit". IE We can give you a simple setting today and tomorrow your back asking for another setting and the day after and the day after. With ye olde service manual in front of you the questions and our time answering them, is lessened.

 

[fishon71]

Re: 6 hp Nissan four stroke valve adjustment - how to?

Called Nissan as some nice gentlemen suggested - had my answer in 2 minutes, no hassle, no cost - thanks for that info

intake .004
exhaust .006