running on 2 of 4 cylinders

[fullsize_chevy]

Does anyone know if there is a way to get a 2004 mercury 115 carbureted 2-stroke to run on all 4 cylinders all the time? By design, it runs on only 2 cylinders until 2000rpm. At 2000rpm, the other 2 kick in like turbo.

 

[Laddies]

Re: running on 2 of 4 cylinders

The reason it idles on 2 cyls. is there is no low speed circurt in one carb. the reason that was designed into the engine was to help it get off the pipe so to speak, when the engine was first started the would ldle alright but when ran up to speed they would not come back to idle inless shut off and restarted is the way it was explained to me

 

[jimmbo]

Re: running on 2 of 4 cylinders

No idle circit? Hmm... So what prevents the engine from seizing from lack of lubrication? Don't say oil injection, cause Merc doesn't injcct the oil into the crankcase, but just premixes the gas/oil just before the carbs

 

[Fishallot]

Re: running on 2 of 4 cylinders

You've gotta change the carb if you want that motor to idle on all cylinders. A small amount of oil/fuel enters the engine to keep it lubed just not enough to make the cylinder fire.

 

[rodbolt]

Re: running on 2 of 4 cylinders

we hve tried a few times to add idle circuits and swap the bottom carbs with a set of top carbs to improve idle quality and midrange. we were never succesful. there are some air jets on the upper stbd side that are covered with epoxy you can play with. I have had good results on occasion with it, the manual says not to touch them but occsionally we do. but with all 4 carbs idling the idle becomes ragged and unstable sometimes it takes a few minutes to get it below 1000 rpm. my experince is to keep the set up you have now and work with it.

 

[WillyBWright]

Re: running on 2 of 4 cylinders

The subject has been covered many times. Do a search. You'll go blind before you're able to read all of it.

 

[fullsize_chevy]

Re: running on 2 of 4 cylinders

I've come to the conclusion that it's probably not worth me doing anything about it. It's not that bad. I thought I might ask in the off-chance there was a simple, harmless solution. On a side note, the feature is pretty nice for trolling. The one thing I don't like about it is it is hard to get it to warm up. If it's around freezing temp outside, it doesn't run smooth after running at cruising speed for 10 minutes or so. I guess it needs all 4 cylinders to fire to get it to good operating temps. Thanks everybody...

 

[mixerjv]

Re: running on 2 of 4 cylinders

"The subject has been covered many times. Do a search"<br /><br />Search function seems not to be working. It's not picking up anything before the forum shutdown.