140 Johnson port side fuel

Ordneb

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I have been working on a 140tl79r that had been sitting for several years. I rebuilt the carbs, the water pump, thermostats and lower unit seals. It fires right up but only on two cylinders. The port side does not appear to be working. When I pull a portside plug wire there is no change. I have spark to all 4 cylinders but I swapped power packs to see if the problem would follow it. It did not. So, I would guess that I'm not getting fuel to the port side. I have replaced all the fuel lines as well. I did not get into the reed valves. Could that be where the problem is? I'm not sure how fuel is delivered to each side, but I would think that the top carb would feed the top cylinders, etc. So if both port cylinders are not firing, now what? The portside plugs are slightly damp after I run the motor and I know that they have good spark. Starved for fuel? Any suggestions would be most appreciated. Thanks.
 

Ordneb

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I did not rebuild the fuel pump. The filter is fine and the pump sends fuel to the starboard side cylinders so I would think it's okay too. If the top or bottom cylinders were not firing it would be likely that a carb was not working. But both top and bottom cylinders on port side are not firing. Not sure what to look for. If the fuel pump was failing wouldn't all the cylinders fire now and then?
 

Ordneb

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Compression is 120-122 on all four cylinders. Or it was before I started the motor up for the first time. I'll check it again.
 

emdsapmgr

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Your swapping of the power pack is a good test. If one pack was bad, the no-fire problem would move to the other head. It did not, so you'd think it would be a fuel-related problem. Unlikely the reeds. Could be a fuel restriction on the port side of both carbs. That would be really unusual. During your carb overhaul did you remove the high speed and idle jets to visually inspect them? Your assumption that if the starboard plugs fire, then the carbs are getting fuel and it would seem normal that the port side of the carb would also have fuel. Also when running with the plugs in, test the spark plug wires for firing with an inductive timing light. The flashes from the gun will show the quality of spark on each wire. Compare to the starboard head. Sometimes plugs act differently when firing under compression.
 

Ordneb

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Thanks for the ideas. I'll do a compression test tomorrow. I did not take the jets out when I rebuilt the carbs. I did pay special attention to trying to make sure that they were blown out. I'm with you on the carbs. The starboard side fires so they should be dispensing fuel to both sides. When I pull the plug wires off of the port cylinders there is no change in how it runs. NONE. There is good spark to all four cylinders. I'm stumped unless the compression test tells me something. I'll let you know.
 

SilverSS07

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I think I finally found the problem with mine that had similar symptoms. The cowl is grounding out the plug wire on the bottom port side. Try running it on the water with the cowl off and see if it's any better.
 

Ordneb

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Hey Silver, thanks for the suggestion but my problem exists even in the yard on the muffs with the cowl off. I just ran a compression test and still have 120+ on all four cylinders. When I took out the plugs the port side were wet on the electrodes and the starboard side were dry. Made me think that maybe my spark wasn't strong enough - weak coils. With my homemade spark tester (screwdriver to a ground) I can't really tell any difference between any of them. All seem to have more than adequate spark - jumping more than 7/16". Is there a way to test coil output with a multi-meter? What should it read? And, wouldn't it fire even with weak spark? Man, I'm stumped. Someone suggested that I had stuck exhaust rings but even if that's true that wouldn't affect firing would it? Thanks guys.
 

SilverSS07

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Wish I knew more to help ya. Definitely make sure carbs are clear. Did you swap the coils? You can test the coils with an ohm meter. Assuming it's the same as my 1983 140 the specs are 0.1 + minus 0.05 for primary winding and secondary winding should be 275+or minus 25 ohms. Have you checked the plug wires? I would think it's has to be ignition related too since it affects one side.
 

emdsapmgr

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You just noted that the port side plugs were wet. To me that indicates that the fuel is flowing through the carbs to those two cyls. Also, wet plugs can be a sign there is no spark. I'd think you want the port plugs to look like the starboard ones, where there is spark and fuel-and the engine runs on those two cyls. Again, I'd check for spark on the port two plugs with a timing light to confirm they are sparking-when the engine is running.
 

Ordneb

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I'll try to run down a timing light tomorrow and see what happens. When the engine is running, even though it is only on two cylinders, nothing happens when I pull the plug wires on the port side. Rather, the only thing that happens is I get zapped! So there is spark there. Maybe not enough though. I was going to swap out a coil but I can't get the positive side wire out of the plug and I didn't really want to make a bunch of splices. I'll let you know how it goes tomorrow. Thanks guys.
 

jakedaawg

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I suppose if the exhaust cover was broken or loose or leaking that you could not be getting the right fuel/air charge into the port side. Very remote but check to see that it is tight anyway.

Are you sure the plugs are wet with fuel and not water?
 
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SilverSS07

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I was looking around last night and found a thread somewhere where someone had a similar problem and it was the timer base. The timer base connects to each powerpack- one or port and one for starboard. Switch them and see if the problem follows.
 

Ordneb

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Well Silver, I think you might have solved the problem. Before I read your last post, this morning I took off the carbs and blew them out again. Not dirty, but made sure the idol jets were open and everything was in order. Put them back on, started her up and whamo, the port side is now working. Unfortunately, or maybe not, now the starboard side refuses to fire. Both top and bottom were cold and when I pulled plug wires there was no change, so obviously running on two cylinders again, just a different side. I don't know if the info you found on timer bases is the answer, but it could be. Do you recall if the problem was strictly limited to one side, and could it or would it be intermittent and possibly change sides? I don't know how the timer base works, but if it is something that doesn't simply burn out then it could possibly change to the other side. Electrical geniuses to the rescue please. I know nothing about the timer base except how to change it out. Pricey part, but worth it if it does the trick. Could I just be doing that poor of a job cleaning my carbs and moved some kind of blockage to the other side? Doesn't sound too likely, but at this point I can't rule anything out.

Anxiously awaiting your advice. Thanks.
 

emdsapmgr

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If you are handy at electrical troubleshooting, have a look at this website: cdielectronics.com. Probably best to check the cranking output voltage on both the timer base and the stator. The website shows condemning output voltages, which are accurate. You will need a special "peak reading" voltmeter in order to check the output voltages. The timer base puts out something like 0.4 volts and the stator a minimum of 150. But check the website for your specific engine's normal voltage outputs. Power packs do odd things when they don't get the correct voltages/signals, so back up and test these two expensive items first.
 

SilverSS07

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Sorry I haven't been on here. Every time I tried to log on the site was down. I don't remember where I found it try to Google timer base Joe Reeves and you should be able to find it. I'll see what the fsm says later when I get home but like emdsapmgr said the cod site is good but you'll need a dva and multimeter to test it. Did u try switching the connections to the power packs and see if the problem follows? From what I read carb problems should affect top or bottom cylinders, power pack or timer base affect port or starboard side.
 

Ordneb

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Well, after checking everything I could, weighing all the evidence and after a long talk with a master boat mechanic, I stuck my neck out and ordered a timer base. I do not have a dva and could not do the electrical testing, but logic tells me that my problem has to be the timer base. The part should be here later this week and I'll let you know the results. Prayers are most welcome!
 

SilverSS07

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I would say it's the timer base since the power pack is good. Sorry I searched again and couldn't find what I found the other day lol. Haven't been on here as much since I bought a mig welder the other day and am trying to teach myself how to weld:). But from what I read before if it was a left bank/right bank issue it was a power pack or timer base. I'm anxious to hear your results as well!
 
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