3 cyl vs 2 cyl

[smsscuba]

I recently bought a 1998 Johnson 35HP. Apon collection I learnt that it was in fact a three cylinder outboard.My question is what sort of advantage does a three cylinder have over a two cylinder?

 

[wilde1j]

Re: 3 cyl vs 2 cyl

Not much, in fact it probably weighs more the a 2 cyl motor.

 

[Chinewalker]

Re: 3 cyl vs 2 cyl

I believe the 3-cylinder model is a loop-charged 2-stroke, where the 2-cylinder is an older style crossflow 2-stroke. Theoretically, the looper ought to be a bit more efficient. I've never run one of the 3-holers, so I can't say if that holds true, though...

 

[emdsapmgr]

Re: 3 cyl vs 2 cyl

That 3 cyl has a lot more torque and power. It should run circles around a 3 cyl 35-according to an owner of one.

 

[Chris1956]

Re: 3 cyl vs 2 cyl

A lot of folks will say that odd number of cylinder 2 cycle motors run the best. I do not have any personal experience to say one way or the other.

 

[Faztbullet]

Re: 3 cyl vs 2 cyl

Just got thru servicing one for a duckhunter and it idles a whole lot smoother than a 2 cylinder 35hp. I agree with Chinewalker and empsapmgr it will be better on fuel and have more torque..

 

[smsscuba]

Re: 3 cyl vs 2 cyl

Thanks for all your input fellow boaters, another quick question, it came with a 4 blade prop, any difference than a 3 blade prop?

 

[Chris1956]

Re: 3 cyl vs 2 cyl

Generally more blades is for heavier loads. Higher performance boats will use 2 blade props, workboats 4 blades. There are some high performance 5 blade props, however, so the rule is not hard and fast.

 

[emdsapmgr]

Re: 3 cyl vs 2 cyl

More blade area is good for control and pushing heavier loads. The 4 blade should work well.
All the new Merc 9.9 kicker motors spin a 4 blade prop.

 

[Grumman59]

Re: 3 cyl vs 2 cyl

I have the 25hp version of that Johnson and compared to Johnson twins I've owned (40, 50) it is a beautifully smooth running engine. Also uses a 4-blade.

Only problem I've heard about with these motors is with the oiling system. Mine has been removed so I run on pre-mix.

 

[boobie]

Re: 3 cyl vs 2 cyl

This mtr was probably one of the sweetest mtrs OMC ever built. If you plan on keeping it take that &*^%#$^&*& oiling system off of it and mix your fuel 50:1. Removing that system is not hard to do and may save you having 3 scored pistons at one time.

 

[samo_ott]

Re: 3 cyl vs 2 cyl

Call me old school but I like the 2 cylinder 1 carb engines. And J/E made a heck of a lot of the 40 hp's for a long time. Simple and easy to work on and cheap. Yeah, probably less torque though.