Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 9:00:12 AM (updated 9/1/2014 9:18:08 AM)

  I have talked to you several times on the phone. You suggested I try the four blade prop on my 20 foot Sylvan Pontoon boat and so far it does great. I installed a new OEM Mercury 50 hp 2 cycle power head on this boat in the spring. I rebuilt all three carburetors and of course replaced all fuel lines. I run non-ethanol gas with sea foam added often.

       The one small problem that worries me is when its cold and first starting off I can get 5000 to 5200 rpm's at full throttle. Yesterday it would scream and I thought finally this engine has broke in. I went about two miles and let it sit for about an 30 minutes. When I started back across the big water I could never get it over 4600 rpm's . It just did not have the same sound as when I first took off. I just want to make sure this engine does not blow like the original one did. I am using the oil injection as all the parts were new on the new power head. It is using oil from the tank so I  do I know its working. I also am still mixing about an once per gallon to be on the safe side until this engine has about 50 hours on it.

     I tested the compression about two weeks ago and all cylinders are 120 psi. I had tested the compression with the engine cold a few days before that and all I could get was 95 psi but they were all even. It did sort of worry me but I was told this was fine. The next time I tested the compression I made sure the engine was warm and the throttle was at wide open position and thats when it showed 120 psi. I am a mechanic and been working in things for over 50 years but not much experience with marine engines. I do understand 2 cycle engines as I have worked on many in the past except boat engines.

    It may not be anything to worry about but it was showing the same signs as it is now just before the other engine went south. I am planning on installing a heat gauge to monitor the temps, just to be on the safe side. No alarms on this boat works and from what I read the oil alarm is not much good anyway as it only monitors how much is in the tank. I never let that get low. Thats why I am installed the temp gauge to see what my engine is running at. Like I said I may be just paranoid about all this but after spending what I did I want to make sure this new engine lasts me a long time. Thanks for any help and always enjoy reading your replies here. You do know marine engines. I just wish you were close to lake martin.

   One thing I have not checked and I know I should is the fuel filter. I thought I had told the person that helped me install this engine to change it but to tell you the truth I never checked. I need to replace it first and then let you know. Will any aftermarket work ? Maybe 5/16 inline that I could take with me. This is a 50HP Mercury 2000 model.  I will post back the results. I also will install a water seperator filter on it and maybe some clear line to see if I am getting air. What you think on this suggestion ?

Thanks 

Name:	CAT BOAT -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 10:40:47 AM

Not sure what to say.  Did you replace the Reed Valves when you replaced the powerhead?  Perhaps they are weak or one of them is broken?

Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 3:58:20 PM

I did not replace the reed valves. It seems as if the reed was bad it would not have run for the mile yesterday at 5200 rpm's. This engine cranks the time you touch the key and idles great. I was just at the boat and it used  oil yesterday alone with about 3 gals of fuel so I know the oil injection is working perfect. It also has a new fuel filter on it. This problem was there starting in about 2009, could have even been that way before but my son did not pay any attention to it. I now own the boat so I will try to figure whats going on. Like I said it may not be nothing and just me thinking that something is going on.  I rebuilt the carbuertors two times since 2009 myself  and really did not see anything wrong with then then. I will keep you updated.

Name:	GoneFishin -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 7:35:19 PM

Take it to Cat's shop and let him hook up his diagnosis software  program. I am sure you can trust  him to bill you fairly. 

Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 8:53:36 PM

  This is an older engine with carburetors and I don't think any software will pinpoint the problem. It is not fuel injected and has no computer to control the fuel. I think I have it narrowed down but thanks for the info anyway. I am going to try a 3 blade 9 degree prop and see what happens. I have one for backup and will install it when I get back to my place on the lake. Like I said its running fine but just worried about the top RPM's this Mercury is supposed to turn. I know lots of things could cause this but I just don't want to burn this engine up again. Cobra

Name:	CAT BOAT -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/1/2014 9:14:17 PM

There are MANY diagnostics available to you.  Vacuum check the carbs.  (Vacuumate system)   Ignition Mate system to check ignition.  Ohm the coils.  Maybe there is nothing wrong.  But normally, if you think there is, then it is.  Your call, curious as to what you find.

Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/2/2014 6:27:08 PM

I was trying to edit my post and hit delete. Oh well. I will update what I find and thanks Cat for the info. Cobra

Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/4/2014 7:37:04 AM (updated 9/4/2014 7:39:36 AM)

  Cat, I removed the cover Tuesday and noticed oil everywhere. I found the oil line off the block on the starter side of engine. There are four barb fitting, two straight and two 90 degree ones on side of block. Both have short lines on them. One had blown off and from looking real close it looks like he used the incorrect size.

      I got the right one and replaced it with zip ties. This is the second time an oil injection line has blowed off this engine. The first time was within 2 hours of getting this engine back running. I had noticed after running it last week it used more oil than normal from the tank. This was just a mistake that was made by the person I hired to do the job that should never have been made. The original line was a thick black  hose and what I was give at a local boat shop yesterday was clear line that looks like line trimmer line.

     I just happen to have a piece from the last time and I used it instead. I have still been mixing oil at the rate of about 100-1 just to be sure on break in. I am not even sure what purpose these tiny oil lines serve ? Would this effect the running of the engine if these lines blew off ? 

      I know the first time the oil line came off it would not idle and it made a mess. I cleaned everything up and it looked new again. When I removed the top cover this week again I witnessed a  mess again. All the oil injection is new being I bought a new OEM power head so would you think I should leave the oil injection as is or should I just disable it and mix my own.

     I am tired of worrying about something happening that could damage this new power head. I am not sure how exactly to remove the oil injection and would appreciate it if you could shed some light on how to do this. I would just bring the boat to you but I am in AC and you about 60 miles away. I also do not have anything to tow the boat with as of yet.

       I have read from many boat forums where some say remove the oil injection and some say leave it along. I have no alarms working and from what I understand these oil alarms are not much worth to begin with as they only tell me my tank is low ? I would also like to install a manual temperture gauge where I can see just how hot this engine is running. Could you suggest where I can purchase one or maybe sell me what I need. I can do the job when I get this boat out of the water this fall.

      I know I am asking lots of questions and if you don't want to answer me I understand. You are the only person who has took the time to help me on marine engines. I worked on engines for over 50 years but never marine ones. I appreciate you being here on the forum to aid in any small problems people have. I enjoy reading your replies to others.

       I drove this boat yesterday after replacing the oil line and got it to 4800 rpm's and it seemed to run fine. Maybe the tac is off but I know last week it hit 5000 rpm's but only for a short time. It cranks fine and idles fine. I can live with it getting only 4800 rpm's as it is running great again. When I drove it last week I could not get over 4500 so maybe this line being off could have been the problem ? Thank for any tips. Cobra

Name:	CAT BOAT -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/4/2014 8:30:28 AM

This is probably something we need to look at first hand.  I will check and see when we have service calls in AC. 

Name:	cobra -	Reply
Subject:	Cat, maybe you can shed some light
Date:	9/6/2014 4:18:04 PM

 I got it running much better Cat. The timing was off 5 degrees. I checked it at idle and @4900 rpms while moving down the lake. Brought it back to dock and changed it to what them manual said. I replaced all three plugs and all new oil lines. I think I will just leave it along as it ran great yesterday. I run it for over an hour and not a problem. It will now crank the time I touch the key. Thanks anyway.