nissan timing again

Don Eskelund

Cadet
Joined
Apr 27, 2001
Messages
14
Re: nissan timing again

Thanks for the comeback pinkmouse,<br /><br />I bought the motor new in 1987. I believe all the 3.5s came with 2 blade props that year, while the 2.5s came with a three blade prop. The Serial# is (309-1) 56461, so it is a real early one. It has four magnets in the flywheel, all of them are there. I used the motor for four or five years. The end of the last season she started kicking back and did it more often and with more force as time progressed. I would guess we are talking 4 to 6 weeks, but this was a long time ago. I haven't really used the motor since except for sporadic attemps to diagnose the problem. New boat, large summer projects, etc., but I hope to have some time to use the old homebuilt some this summer.<br /><br />I agree I might as well remove the head, just to see what is there. From what I can see through the exhaust port the motor has not carboned up excessively. <br /><br />I am going to borrow my neighbors dial guage and check the run out of the shaft that the flywheel sits on. It seems a few thousands out here could throw the timing out guite a bit. The points break within a mm of TDC. I am using the old sliding guage I used to time my old 2 stroke motorcycles with (static). It worked good for the purpose back then.<br /><br />I doubt anything I have said has helped much. I will post again after I put the dial guage to the shaft. I do thank you for your comments, ideas, and support. It helps keep me going and keeps the frustration level down somewhat. The motor would make an expensive and ineffective anchor and I believe the enviromental agencies frown on chowdering outboards these days.<br /><br />Thanks again<br /><br />Don Eskelund
 

Don Eskelund

Cadet
Joined
Apr 27, 2001
Messages
14
Re: nissan timing again

I'm back. Shaft checked out OK: 1.5 thousands off total and I guess that needs to be divided by 2 which would be 0.75 thousands runout on the shaft. I did notice that the bolt holes through the flywheel that hold the magnets in place appeared to have been drilled, filled, and redrilled in slightly different positions. This motor could have been like this (at least to some degree) her whole life and I didn't know it until I had used a nondefective motor for awhile. <br /><br />Next step is to reassemble and try the flywheel off my short shaft 2.5 nissan on this motor and see if this makes any difference. <br /><br />I have been wondering how one mavericks a mag though. Just my curiosity getting the better of me.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: nissan timing again

What "maverick" did was disconnect the points (simulating open) at higher rpm so that the initial voltage induced in the coil fired the plug instead of building a field to be collapsed later. In normal operation it is this collapse that fires the plug. By allowing the initial voltage to fire the plug you got an "automatic" 15 to 20 degree advance and a big jump in torque and combustion chamber temp. On a racing kart you either got a kick in the butt for passing or you got very bad noises.<br /><br />JB
smile.gif
 

carolesueII

Recruit
Joined
Jun 21, 2002
Messages
2
Re: nissan timing again

Don,<br />I have a Nissan that is doing the exact same thing. Checked about all the same things you have and cannot locate the problem. Did you ever find a fix for this problem? Please advise, I am going nuts with this one also.<br />Thanks.
 

rjmtz

Recruit
Joined
Aug 15, 2010
Messages
1
Re: nissan timing again

Hi I need help on how to set the timeing on a 1998 90 hp nissan outboard :confused:
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: nissan timing again

It's timed by adjusting the linkage. The procedure and values can be found in your service manual...The engine cannot come out of time by itself, so unless someone was screwing around with it, it should be to spec right now.
 
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