1981 85hp Suzuki Fuel Problem on 1st cyllinder

[firstboat19]

Hi everyone. I have an '81 85hp Suzuki. It idles rough, actually it stalls all the time while idling. But runs nice on higher rpm(s). I took it to shop and here's the problem: first cyllinder won't suck in any gas/air mixture from the carb. It does suck in a little at higher rpms.<br />Here's some history on the engine. I bought it this winter, it's been in storage ever since 1981, it was a demo. Never put to water, never been repaired, the paint is shiny and intact around bolts, etc.<br />Does anyone know what might be causing this? A leak? Mechanics said it's probably a faulty crank, but it would cost big bucks to replace that...<br />I was thinking it might be a leak around the flywheel - the engine has been in storage for so long! There are no visible leaks, but I need to take off the flywheel to check that out.<br />Has anyone else experienced the same problem?<br /><br />Thank you in advance,<br /><br /><br />Nik

 

[jim dozier]

Re: 1981 85hp Suzuki Fuel Problem on 1st cyllinder

Normally I would suggest a dirty or maladjusted carb idle circuit for the idle problem, especially on an engine that has sat for a long time unused. However, your comment about the #1 cylinder not sucking suggests other problems to investigate. Do a compression check and report the numbers. What exactly do you mean when you say the cylinder does not suck? Be specific. Pull the airbox off the carbs and put your hand over the carb throat while the engine is running. Is it or is it not sucking air? If it isn't you have big problems and will probably need to pull the head to check for piston damage. Or do you mean it just isn't getting fuel? If fuel is the problem check the fuel pump and the carbs as they may need to be cleaned and rebuilt.

 

[rodbolt]

Re: 1981 85hp Suzuki Fuel Problem on 1st cyllinder

hello<br /> no need to get jiggy.<br /> you may need to find a real tech not just a guy with a box o tools. the flywheel can be indexed rapidly to check for a crank throw that is off. the carbs on that motor MUST be set with a manometer. cant balance them anyother way. and it is part of PDI.iI would suspect some trash is in the idle circuits of the top carb or something like that.might take 3 min to index the crank and rule in or out the crank theory.<br /> my money is on dirty carbs

 

[firstboat19]

Re: 1981 85hp Suzuki Fuel Problem on 1st cyllinder

Thank you all for your replies.<br /><br />Comment reply to jimd.<br /><br />The top carb does not suck in any air (pretty much). Compression was good on all cyllinders when it was installed it this summer (I've only used the boat a couple of times).<br />The mechanic I was talking about even switched top carb with the middle one, and the problem remained on the first cyllinder, suggesting it is not the carb that is at fault.<br />I took a look at the repair manual I have for this engine, and it said that for 3 cyllinder engines, the rods could not be separated from the crank (I hope I understood that correct). So I guess if I need to change crank I need to replace the whole deal. Also, the repair place quoted me a $2000 price for the crank.<br />Hope to hear something optimistic.<br />Nik

 

[jim dozier]

Re: 1981 85hp Suzuki Fuel Problem on 1st cyllinder

I don't know because I'm not there but if the engine is running, rough or not, and you put your hand over the carb throat with the throttle open it should feel like its going to suck the chrome off a trailer hitch. If it don't you got a hole in the piston or something bad. Is the throttle linkage set up right? I mean is the throttle plate opening? Pull the spark plug and look at the piston top and see what's going on in there. That said, you would probably have experienced other bad things like weird noises with a bad piston, so I'm agreeing with Rodbolt its probably just a dirty carb.