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1989 35 horse mercury surging/power loss etc

Justin J

New member
Hey guys!

I've been scrolling over the posts here for awhile with some different issues I've been having but now it's about my own motor I need help with
I have a 35 horse mercury that came on my 88 bass tracker I bought recently which the owner said didn't run Because of possible "water in the bottom cylinder" old owner said the compression was 150 on top and 130 on bottom. Anyways, when I got it home I got to looking at it, got it all hooked back up and put it on the hose to test. Well it started right up and seemed to run ok but it was stuck in forward gear. I got that issue fixed and took it out on the water this afternoon. I could not get it to go over 7-8 mph for awhile and then it started to sort of surge and it really sounded good And then die back down on and off for a few minutes and then it finally decided to really kick up and I hit a plane for a few seconds and it does back down again to 7-8 mph... After it did that a few times it was really hard to start and would die every time I tried. I know the plugs are getting spark, but not how strong, and I know it's getting at least some fuel.

I'm going to change the plugs and wires soon but I'm just wondering what else should I try and what typ. Of issues could I be dealing with?

Any help would be awesome and greatly appreciated.
 
Sounds like you might be loosing spark on a cylinder. Make it do this, then immediately shut it down (do NOT let it idle) and pull the plugs. The wet, sooty one is the bad cylinder.

Jeff

PS: Why well be a bad coil. Seen a lot of them go bad lately.
 
Sounds like you might be loosing spark on a cylinder. Make it do this, then immediately shut it down (do NOT let it idle) and pull the plugs. The wet, sooty one is the bad cylinder.

Jeff

PS: Why well be a bad coil. Seen a lot of them go bad lately.

So it could be having no spark most of the time and then randomly gets spark on one cylinder to make it up the power for a few seconds? Pull the plugs immediately after it falls on its face? Could that be an indication of plugs and wires?

Thank you for the reply!
 
Thank you. I was also wondering if there could be a chance if the carb could be partially responsible? Or would that be a get new coils and go from there kind of deal?
 
Thank you. I was also wondering if there could be a chance if the carb could be partially responsible? Or would that be a get new coils and go from there kind of deal?
 
might sound silly but check the state of your fuel lines and connectors i had something of the same issue on boat i just bought fuel line and every connector falling apart and even male connector in the outboard was slightly bent but meant fuel was intermittent
 
Good point. I've had so much trouble with fuel feeding over the years I took some damn good advice and installed an electric fuel pump (with a pressure gage). Works great and never has 'flow problems'.

Jeff
 
Ok guys, so... I have put a new tank with new gas and a new fuel filter and changed the plugs, and I only got one coil but I tried it on both #1 and #2 and on #2 it seemed to help some as it didn't die as soon as you start it. I pulled both plugs right away and the both looked the same, no water on them. Now my issue is that the engine is not peeling out of the telltale consistently but water is pooling up in the bottom of the scowling area under everything. When it does squirt a little out the hole, it's really hot but not boiling hot. Oh also it doesn't sound like it's running at 100% still. Just sounds kind of ... Rough I guess. No rpm drops at idle or around 2000 rpm Like its missing but it just sounds rough. I'll try it on the water tomorrow maybe.
 
I forgot to mention as well, it looked like some fuel was dripping from somewhere on the carb after it had Bern running a couple minutes and shut off. Not sure where it was coming from exactly.
 
So we went out on the water for some fishing and the engine still is hard to start and doesn't want to idle slow. I have to start it and try and put it in gear real fast before it dies. Once I got it in gear and we moseyed past the no wake zone I opened her up and she ran! Ran good around the whole lake. Still kinda felt like it was missing some now and again, but otherwise it didn't sound too bad. she just won't idle. Now my question on that engine, serial number 0B341430, is there multiple different carbs that could be on it which would make getting a kit difficult?
 
will carb repair kit, part number 1395-5109 be the right kit for my engine? Its the only one I've found that has all the little bits and pieces and not just the gaskets and washers.
 
will carb repair kit, part number 1395-5109 be the right kit for my engine? Its the only one I've found that has all the little bits and pieces and not just the gaskets and washers.
hi Justin I had my boat out and still doing the same called a outboard mechanic and he says dirty carbs and as its the start of the season over here he said it would be the end of may before he could get to me unless I took off carbs and took them in my carbs are a nightmare so he says as they are 4 in a row on 1 unit. so I took them in yesterday and he opened the first 1 and it was filthy he is fairly sure it is the problem I just got boat and know it sat for a year seems the fuel we are all getting is of poor quality hes done 4 carbs this week already and loads more to do he's going to sonically clean them well worth having a look inside yours. mine is performing just as bad as yours good luck
jim
 
I'm not sure if anyone is following anymore, but I was finally able to get in and check the compression on both cylinders, and I ended up with just under 120 on top and just over 120 on bottom. I pulled the carb right now and it is sitting in soak until tomorrow. I got a rebuild kit for it and will have that done tomorrow and have it re installed. Stay tuned for an update as I plan on testing Saturday.
 
Also forgot to mention when I got the carb apart it had a lot of varnish in the bowl and when you pressed in the needle it would stick a few seconds and then drop back.
 
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