Timing question. 1966 18 hp Evinrude.

steviecops · Jan 14, 2005

Hi I got my old 1966 Evinrude 18 fastwin running yesterday ;o). I found it very sensitive to adjustments on the idle screw, ie, sneezing alot if I screwed it in just a fraction too much. But now it seems to be running O.K. It idles nice and seems responsive. Here's the problem. With the engine at idle, the pointer on the twist grip throttle control is pointing between the START and SHIFT position. The engine idles fine there, but if I adjust the idle speed screw to try to get the pointer to the SLOW position, the engine coughs and dies. The throttle pick up timing is spot on, and I've fitted new points set at just above .020, to allow for seating, as per the manual. I can't see any way to adjust it so that the engine idles when the pointer is on the SLOW position on the twist grip. Is this a problem? Is there anything I can do to correct it, or doesn't it matter? Thanks in advance. Steve

Dhadley · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

I've never paid much attention to the pointer being EXACTLY on the slow or shift or whatever. I always just figured that was to give folks the general idea of which way was for what. If it idles fine, shifts fine and runs wide open fine, I'd say you are home free!

matthew hardman · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

i agree if it worries you to much your local library should have a book on that motor that should give you the exact I checked it out to help me with the adjustments on my morors it is very handy good luck

Chinewalker · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

I wouldn't worry about it. There's so much slop in that throttle system that you can be off quite a bit on the pointer with absolutely zero effect on the motor's performance... Just run it! - Scott

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

O.K, thanks for the replies. I wasn't that bothered, but just thought I'd check. I ran the engine again this afternoon and now seem to have another problem! I thought it was a bit too much that everything worked right first time! The motor is difficult to start from cold, but once it starts it seems to run fine. But this afternoon, it started sneezing and coughing, and cut out a few times. I think it's running lean when it starts sneezing, but I can't understand why it only does it sometimes. I took the plugs out to check them and the top one is black and sooty, while the bottom one is oily and wet. Yet I'm getting a very good spark on both. I cleaned the carb thoroughly, but couldn't get hold of a carb kit. (I've now ordered one, and a fuel pump repair kit). Whilst cleaning the carb, the bushing that the idle needle screws into, came out! I just pushed it back in and reassembled the carb. I read on a previous thread that Paul Moir had the same problem once, but didn't see any fix. Could anyone tell me what't the best thing to do with it? I really want to get this old engine running sweet because it's a great engine. It's so strong that it'll keep trying to run even when it's all but starved of fuel! Thanks in advance. Steve

matthew hardman · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

make sure that you set the neddle valves at the right settings

steelespike · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

The sneezing is a classic lean problem.You may be sucking air in the fuel line somewhere.I would check the fuel line connections and connectors.When adjusting the idle mix set it slightly toward rich.You want to be sure the fuel system is clean or it will keep messing up your carb.Be sure the tank vent is open.The oily plug may be a leaky fuel pump diaphram though this usually seems to cause excess smoke as well. If you dont know the history it would be a good idea to do the fuel pump and water pump anyway.

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

I spent a long time adjusting the idle needle, the high speed is fixed. I thought I had it set up just right because the engine was running great, but when I started the engine again from cold, it was hard to start, then it started sneezing. The fuel lines are all new and all have new connectors fitted, so I know there are no air leaks there. I've done the water pump and the engine is spraying plenty of water out of the holes. I also replaced the thermostat and head gasket. The head feels hot, but I can hold my fingers on the top, so I think the engine is operating at the right temperature. There is however, a lot of smoke! As a matter of fact, I wondered why it was smoking so much because it's running on 50:1 the same as my other motors, and they don't smoke as much. But surely, if it was the fuel pump diaphram, the mixture would be rich? Yet the sneezing is caused by a lean condition. I'm puzzled, but the carb kit and fuel pump repair kit are on their way ;o) Any ideas about the needle bushing? Thanks. Steve

Paul Moir · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

I don't think the bushing will be a problem if it pushed back in alright. I suppose you could coat it in loctite to retain it, but the packing and packing nut should do that alright. All it needs to do is keep from turning so you can adjust the needle. Was the end of the needle in good shape? The one I had had been "staked" with a chisel to put a burr on it and hold it in. I simply repeated that process (with the needle in the bushing so it wouldn't collapse of course). I'm thinking along the lines of steelspike on this one. It's hard to tell this time of year about smoke since a lot of that is water vapor (it's cold out!) and normal 'running in a barrel' smoke. But if you think it's excessive, it could be that one cylinder is getting a different mixture than the other. That could be caused by a crankcase leak, uneven compression or a fuel pump diaphram leak. The spark plugs should tell you if that's what's happening.

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Hi Paul The bushing in mine was completely smooth, and as you say, tightening the packing nut held it enough to be able to adjust the needle. The end of the needle was in good shape. The spark plugs were new yesterday and on taking them out to inspect them today, the top one is black and sooty, the bottom one oily and wet. So something different is happening on one of the cylinders. Compression is just under 100 on the top, and just over a 100 on the bottom. My carb kit and fuel pump kit won't be here til next week, so I'm a bit stuffed until then. Is there anything else I could be checking? Just as an aside, how much up and down play should there be on the magneto plate. I noticed that while the engine was running, the magneto plate was moving up and down a bit. When the engine cut out, I moved it by hand and there is about 1/8 inch play in it. Thanks Steve

OBJ · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Hi Steve....take a look at where the roller is in regard to the reference mark on the came when the engine is at it's best idle. If it's still above the mark, the throttle plate is still open. When you go below the mark and the engine stalls, it usually means the needle needs to be open more or you have some other problem as the guys have mentioned. Do be aware of running to lean on the needle. Sounds like, from your description, that you are a little to far in with the needle. And another $.02 cents worth...

on occasion you might have one cylinder that is not firing or fires intermittently at low end and will make ya' think that it's fuel related. Might pay to just recheck the point settings and connections under the flywheel. OK...I'm done....

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Hi OBJ I've actually had the engine idling well with the roller to the right of the mark, (looking from the front), and not touching the cam on the

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Hi OBJ I've actually had the engine idling well with the roller to the right of the mark, (looking from the front), and not touching the cam on the magneto at all. That was after initially getting the engine running, and spending time adjusting the needle. This sneezing thing seems to have started since I left the engine sitting for a few hours. I will take the flywheel off and check everything under there again, although I've checked with a spark tester and the sparks are very good with just a slow half pull on the starter cord. Thanks Steve

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Oops!

OBJ · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

OK Steve....if the roller is off the mark at a good idle and it dosen't kick and act like a spoiled child, the settin must be close. But again, do be aware of running with the needle in to far.

Paul Moir · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Stevicops - search out Joe Reeves post for fixing a 'wobbling armature plate'. It works really well, and I don't think I've seen a pre'75 OMC outboard that didn't need it. The wobble makes for a noisy ignition plate and sometimes if it's bad enough the coils strike the flywheel. Even worse, it throws the timing off since the adjustment on the points goes wonky. OBJ's got a good point about one of the cylinder's dropping out at idle. It would be a good idea to re-read the plugs after killing it while it's running 1000-rpms in gear or so, to rule that out. Is your fuel pump connected to the bottom crank chamber or the top one? (I think it's the top but I want to be sure) EDIT: Some of the above is a little outdated...

steviecops · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

OBJ The engine did idle very well with the roller off the cam, that's why I thought I had it made! But when I restarted it from cold, it behaved just as you described! Kicking and showing off! I might have another go at adjusting the needle, but it shouldn't really change just from sitting, should it? Paul Thanks, I'll check out Joe's post for the wobbly plate. I'll try killing the engine at 1000 rpms tomorrow. The fuel pump is connected to the top crank chamber. Thanks Steve

Paul Moir · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

It could very well be the fuel pump causing the top to run rich. If you take off the pump and pump up the primer, sometimes you can see fuel dripping out of the pressure pulse port if the diaphram is ruptured. Not long ago one iboats member was having similair troubles. He ended up completely filling the bottom crankcase chamber with gasoline via a broken fuel pump!

G DANE · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

I've experienced two different problems with the 73 25HPs, same block as yours, giving exactly same symptoms as you have. 1: Leaky upper cranckshaft seal, causing upper cylinder to draw false air, instead of air/gas mixture. When you fatn up iddle micture to make upper cylinder run, lower will flood and foul plug. Condition will be visible by stator plate and flywheen underside contaminated by thin oil from leak. Luckily this seal is replaceable on that particular motor without disasembling cranckcase. Available both from Sierra and J/E dealers. 2: I once spent a month to troubleshoot a little weak ignition on lower cylinder causing it to miss at iddle. Turned out to be a weak condenser, causing combustion on lower to be poor and plug to foul. Make sparks jump a 5/16 gap, when pulling starter cord, if the lower one is weaker, you have your problem narrowed down. This lowtension ignition can really tease, but is great when everything is fine and working. My bad condenser was a new one I just put in. When sparkplug was new, it iddled fine on first trip.

G DANE · Jan 14, 2005

Re: Timing question. 1966 18 hp Evinrude.

Wobling armature plate is a classic on those. I also had one where the screws in the intake manifold had rattled loose - causing excessive sneezing - evinrude flu !! It should iddle with the roller off the cam, iddle speed is adjusted by advancing spark, so is rmp at slow speed. Mine had 120 psi on both, btw.

Timing question. 1966 18 hp Evinrude.

Chief Petty Officer

Supreme Mariner

Seaman Apprentice

Fleet Admiral

Chief Petty Officer

Seaman Apprentice

Supreme Mariner

Chief Petty Officer

Admiral

Chief Petty Officer

Supreme Mariner

Chief Petty Officer

Chief Petty Officer

Chief Petty Officer

Supreme Mariner

Admiral

Chief Petty Officer

Admiral

Commander

Commander