2 or 4 stroke! What do I have.

[noclue]

Wow there is a ton of great info on this board unfortunately most of it seems to be over my head. I recently purchased a 64 Glasstron V-Hull with a 66 Johnson 100Hp outboard. When I purchased the boat the seller told me it was a 4 stroke. However the manuel he gave me was for a 2 stroke. So I figured I had the wrong manuel however when I took the engine cover off I found that my engine and the pics of the enigine in the manuel were identical. Now to be honest I dont really know the difference between the two other than that 2 strokes are allowed on all lakes while some lakes do not allow 4 strokes. Is there any quick way to tell? I included my model number below.

Johnson
100HP
4VML12M

The seller told me the engine was re-built a year ago but has not been started since then. When I inspected the enigine there was definitly eveidence of some recent work (new o-rings new bolts in place and just a general look like something had been done recently). Since im not very mechanically gifted I have elected to take the engine to the shop to have a tune-up but since I cant even tell the difference between a 2 and 4 stroke I'm wondering if you guys can give me some advice on what I should ask the mechanic to do so I dont look like a complete idiot and have the guy charge me for things I dont need. Thanks in advance for any help you guys give me.

 

[WillyBWright]

Re: 2 or 4 stroke! What do I have.

It's a four-cylinder two-stroke. Two-strokes are the ones being banned on more and more lakes, at least the ones with carburetors. When it was rebuilt, a tune-up would've been don as well. I would hope that the water pump was too. I would just ask for an evaluation and commissioning. that's where they check things over in general and get it ready for you to use. Base what you want done on the results of the evaluation. Hopefully it needs nothing. That should cost you about an hour of labor.

 

[05GlastronSX]

Re: 2 or 4 stroke! What do I have.

make sure you use a TCW-3 rated outboard 2 stroke oil and mix at 50:1 ratio. DO NOT use 4 stroke oil or another rebuild will be in order. read up on here about two strokes to learn more...like you said, a lot of good info and very intelligent people.

 

[AguaSki]

Re: 2 or 4 stroke! What do I have.

make sure you use a TCW-3 rated outboard 2 stroke oil and mix at 50:1 ratio. DO NOT use 4 stroke oil or another rebuild will be in order. read up on here about two strokes to learn more...like you said, a lot of good info and very intelligent people.

I agree with 05GlastronSX. If you don't know the difference between a 2 stroke and a 4 stroke, then I would not run the engine until you have a better understanding. We all have to start learning at some point, and I think you would be best served by understanding the why the 50:1 ratio of TCW-3 oil is so important. One quick outing without the proper oil ratio can damage your motor. Just do some searches here on iBoats and the web in general. Before you know it you will understand that you have a good motor, and how to keep it in great shape. Enjoy.

 

[studlymandingo]

Re: 2 or 4 stroke! What do I have.

What everyone is telling you about TCW-3 is important. Two-strokes do not have any internal lubrication other than what is in the fuel. On a two-stroke, the fuel mixture is pulled through the crankcase into the combustion chamber, the oil in the fuel is what lubricates all of the moving parts. No oil in the fuel means everything gets the lube washed off, then no lube. No lube = failure of critical engine components. Make sure that you familiarize yourself with oil mixture ratios and never run that motor on straight gas.

Welcome to iboats!​

 

[noclue]

Re: 2 or 4 stroke! What do I have.

Thanks for all the replys I appreciate it. I found a great article with diagrams on maxrules.com about 2 and 4 stroke engines I thought it gave a very good overview of the two different types of engines. I cant find the link now but it would be really helpfull to anyone that is in the same position im in which is knowing close to nothing about my motor. Im thinking my best course of action now would be to get the manuel specific to my engine and have a professional get her running. From there I think I should be able to keep up on the general and preventive maintnence. Thanks again for the help. Im sure this wont be my last question!