motv8tr Posted August 30, 2008 Report Share Posted August 30, 2008 Hey Ernie, thanks for taking the time to go to Beans and look at my motor, I can't tell you how much I appreciate it Here is the e-mail Norm sent me.... "E.C. (Ernie) Milley was here this afternoon to do a compression test on the motor... his consesus was: 1-top cylinder 52 psi 2-bottom cylinder 150 psi 3-Engine need an overhaul 4-motor needs a new water pump/impeller The boat needs anodes on mounting brackets He did get the motor to start after taping some bare wires and putting the plugs back in but there was not much water spitting out (pump/impeller) unless you revved it up a lot but even then not a lot of water...eventually the horn sounded and he shut it off... Beans" So, I checked my manual to see what the compression should be, couldn't find it....doesn't mean it isn't there Can anyone tell me? What are anodes and why do I need them? Can I run the motor for another year before getting an overhaul as long as I get the water pump/impellar replaced or will I make things worse? Thanks again for your help Maureen Link to comment Share on other sites More sharing options...
ccmtcanada Posted August 30, 2008 Report Share Posted August 30, 2008 Uneven compression greater than 15 psi between the two will make fine tuning the engine impossible. It'll run roughly no matter how you adjust it. Loss of compression could be anything from a seal to a scored cylinder, so it's hard to say what would happen if you kept on running it...likely more damage would be done the longer it's run....but I'm not a mechanic....not even close to one!!! The impeller should be done right away, so that lower end damage doesn't occur. If it were my engine, I'd get it overhauled now rather than later....my gut says it may cost more if you keep on running it. Hopefully Bernie or Tybo (or anyone else who knows about this topic) will chime in with some good advice. Good on Ernie to come out to test out the motor for you!! Good luck! Link to comment Share on other sites More sharing options...
Terry Posted August 30, 2008 Report Share Posted August 30, 2008 I would be looking for a new new-used motor Link to comment Share on other sites More sharing options...
Wild Posted August 30, 2008 Report Share Posted August 30, 2008 Maureen this means that your top cylinder is leaking badly and not doing it's job. The reason why the compression is that low needs to be looked at soon and you cannot trust the motor to run reliably on one cylinder for another season as further damage may be likely depending on what the problem is right now. Anodes are used to prevent other parts of the outboard from corroding faster. Link to comment Share on other sites More sharing options...
Nanook Posted August 31, 2008 Report Share Posted August 31, 2008 I would be looking for a new new-used motor I have to go along with Terry ! If you get the Impeller replaced, cost? and then have to pay BIG bucks to fix the motor, you would prolly find a newer/used one for less bucks. It sounds like #1 cylider is fried unfortunatley........but,as you know I'm not a mechanic. Good luck!! Link to comment Share on other sites More sharing options...
Big Cliff Posted August 31, 2008 Report Share Posted August 31, 2008 The water pump failing has probably caused the engine to over heat and that could have caused the damage to the engine, the low compression could be caused by several things but almost all of them expensive fixes as it would require the motor to be torn down. Looking for a good used motor might be a good idea as rebuilding some of these older engines ends up putting a lot of strain on other components and often causes something else to fail. Oh the joy of owning a boat! Link to comment Share on other sites More sharing options...
TennesseeGuy Posted August 31, 2008 Report Share Posted August 31, 2008 Many of you are happy with trashing this old motor just because it needs repairing. Hope you wouldn't give the same advice to my doctors when it comes to treating my ailments? What if Maureen's motor reads this thread? Link to comment Share on other sites More sharing options...
Wild Posted August 31, 2008 Report Share Posted August 31, 2008 Well if the motor has read this thread I believe it has already googled the repair manual on how to fix a limp piston and has already disregarded any web diagnosis. However I would like some facts before sending the patient to the OR. Link to comment Share on other sites More sharing options...
TennesseeGuy Posted August 31, 2008 Report Share Posted August 31, 2008 Okay, who have you been talking to about my having a limp anything? Better yet, don't answer that one. Link to comment Share on other sites More sharing options...
Wild Posted August 31, 2008 Report Share Posted August 31, 2008 Well I have been told when in doubt to point the finger at GCD ooops you said not to answer that on right? Link to comment Share on other sites More sharing options...
Greencoachdog Posted August 31, 2008 Report Share Posted August 31, 2008 Mo, I agree with the others that say not to use your motor until it has been fixed properly (everything). You'll run a very high risk of damaging the motor further and it will probably leave you stranded somewhere that you'd rather not be. As far as buying a new or used motor... I don't know that it would be worth puting a new motor on a boat with as many years as yours has. A used motor, well you may be buying someone else's problems! If you buy a used motor, have a compression check done before buying it and replace the impeller before using it! Replacing the impeller is part of a maintainance schedule anyway! The low compression reading on your #1 cylinder now is probably from 1 or more of 3 things... 1. a valve, 2. Broken piston rings, or 3. a scored cylinder wall... all of these can be fixed right now. A rebuild on your motor will be expensive, but probably less than buying a used motor. You may be able to wait until this winter and get a good deal on a rebuild jobs when marine dealers are at their slow period. Looking back on your motor, it has been a very durable/tough motor to have lasted all these years. You know whats wrong with this one and what has to be fixed... buying a used one... you just never know. Link to comment Share on other sites More sharing options...
Wild Posted August 31, 2008 Report Share Posted August 31, 2008 Of course low compression could also be due to a warped head or blown gasket , broken piston or as simple as seized rings... you just have to remove the head to inspect the cylinder as a first step before deciding what to do. If the lower end and the crank are in good shape and the cylinder walls are within repairable specs then let's weigh the options. But first find out the real problem with at least a head removal. Link to comment Share on other sites More sharing options...
motv8tr Posted September 1, 2008 Author Report Share Posted September 1, 2008 Thanks for all the input and suggestions, it's appreciated. I am not in a position to purchase a new motor at this time and as was mentioned buying another used one just invites more potential challenges...plus they're pretty darned expensive. Jack (Nanook) put me in touch with a mechanic in Buckhorn, so I will talk to him, see if he will take a closer look at the motor and I will go from there. Thanks again Maureen Link to comment Share on other sites More sharing options...
Guest skeeter99 Posted September 1, 2008 Report Share Posted September 1, 2008 sounds like the overheat and head gasket blown if the impeller was shot the top cylinder is the farthest away for the impeller hence low flow of water or just bubbles causing it to blow very, very easy fix have done a couple in my day and I am still young gasket might be around $50 to $75 or less and even the install at $100 anf hour is still less than $200 i bet my salary it is only the head gasket you have the classic symptoms Link to comment Share on other sites More sharing options...
Big Cliff Posted September 1, 2008 Report Share Posted September 1, 2008 Are you offering to fix it if she supplies the parts? If so, I'll be happy to help anyway I can, I have all the tools just not much time and I don't usually work on outboards. From the sound of it she probably isn't going to have it back in the water for a while and by the end of this month things should start to slow down a bit for me. Link to comment Share on other sites More sharing options...
Bernie Posted September 1, 2008 Report Share Posted September 1, 2008 It is a possibility of a head gasket leak Maureen. If it's a small Johnson twin cylinder they are usually an easy fix. Half an hour to an hours work to replace normally. You need to pull the cylinder head anyway to check it out. An overheated engine can score pistons/cylinders and seize rings. Don't junk the motor until you get it checked out. Link to comment Share on other sites More sharing options...
sirfish Posted September 1, 2008 Report Share Posted September 1, 2008 Mo, I don't want to sound like a "Debbie Downer" but, If it is a 3 cyl. OMC and its the top cylinder with that low compression chances are you broke a ring. Hopefully you stopped the motor and haven't run it as the broken piece of ring will pound the head and piston ruining the head also. If this is the case then a resleeve is in order along with a piston and new or if can be found, a used head. In any event you are looking at a hefty repair bill. This is the voice of experience talking as I have gone through it and found that this was a common problem especially with the VRO motors. Where for some reason the oil doesnt mix right for the top cylinder and it overheats and there go the rings. Take the top plug out and with using a penlight shine it into the plug hole while hand rotating the flywheel until you get a good view of the piston. Look for any gouges on the piston. if it is smooth with a little carbon buidup then you pretty well eliminate that problem but if it is all marked up $$$ If it a head gasket leak then it should be blowing white smoke out the exhaust. Check out www.marinedoctor.com this is a very reputable site with many knowledable mechanics onboard. Good luck. Link to comment Share on other sites More sharing options...
ecmilley Posted September 2, 2008 Report Share Posted September 2, 2008 no problem maureen, didn't have my leakdown tester or borescope with me to give 100% answer, but pretty sure it's in the piston. hopefully just the headgasket but i didn't have the tools or time for the teardown, but have overheated many engines and sometimes the ring gaps get hot enough the expand and touch which will break ringlands, just hope for the best but be prepared for the worst Link to comment Share on other sites More sharing options...
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