Mercury 3.3hp tell tale problem

[Jon7]

Hi there, hoping someone on here can give me some ideas, I just got my engine back from an outboard repair guy, the whole thing has been quite a saga and without going into too much he basically took 6 & 1/2 months to get it fixed, has had new piston ring another piston all new seals, new shaft oil seals impeller and housing and all work was done properly, so after such a long time and a lot more expense than expected we were very excited to get our engine back this week.

Today I have a chance to try it, the strangest thing, it pumps water fine in neutral even when revving up but when in gear on the boat (10ft fibreglass row boat type) it only pumps water fine at low revs as soon as you try to put the revs up it stops pumping water. Does anyone have any ideas what this could be because after all the hassle I had with the outboard guy I just don't think I can do another episode with him unless I really have to. It just seems really weird because when not in gear it pumps water well even at high revs, as soon as in gear when you start to go over idle speed the water heats up dramatically straight away then stops pumping water altogether just blows steam, anyone know anything please I would be really happy to hear some thoughts on this. I was wondering if it was to do with the depth in the water or the angle or something, although I tried other positions for the engine, I really have no idea I just hope its easy to sort out as this is driving me nuts, the boat front does seems to rise up a lot but I didn't think it would stop flow to the engine? Thanks for your help, Jon

 

[ondarvr]

Re: Mercury 3.3hp tell tale problem

I have a 3.3, they are kind of throw-away motors, it really doesn't pay to have much work done to one.

What length shaft and what height transom do you have?

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

I have a 3.3, they are kind of throw-away motors, it really doesn't pay to have much work done to one.

What length shaft and what height transom do you have?

Ah I see, maybe I should have thought about it before paying out loads of money on it. I thought they were well respected little things

Er, that is a really good question I am not sure how to tell, it is a standard shaft or short shaft and the row boat is just a regular rowing boat style fibreglass boat, should I measure something? The propel is definitely below the bottom of the boat but I wondered if it wasn't far enough down or perhaps the boat wake somehow pushes the water past the pick up? It seems odd because it is fine whilst going really slow or revs no problem and pushes water when not in gear so I don't really know. Should I try it in a wheelie bin of water or something to see if it is ok then?

 

[ondarvr]

Re: Mercury 3.3hp tell tale problem

They aren't junk motors, it's just that the cost of repairs quickly exceeds the value, you can buy a good running one for a few hundred bucks.


Post a pic of the motor on the boat, this will help a great deal.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

Ok I will have to get this tomorrow I think as the boat is away now, I will try to get for you tomorrow but it sounds like this could be the problem I dare say that the engine is not sitting low enough, is there something I can attach to make it lower or will I need to swap the whole thing?

 

[MH Hawker]

Re: Mercury 3.3hp tell tale problem

It may be a bit short a picture will really help.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

Hi there, I have taken a few photos and placed them on sky drive here https://skydrive.live.com/?cid=41D8...#cid=41D8FE840AACFEB8&id=41D8FE840AACFEB8!126

Let me know what you think, seems deep enough to me? Could it be something to do with a seal or something in the engine itself? Thanks for your help Jon

 

[Toddboat]

Re: Mercury 3.3hp tell tale problem

Maybe it's time for a new impeller? If the old one is coming apart, pieces of it could work their way into the water tube and water jackets. If you remove the exhaust cover on the side of the motor, you can see if the water jackets have debris or salt in them. You can also see the pistons and rings, in case you ever need to diagnose another internal problem. Don't run the motor until you fix it's peeing problem.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

The outboard guy put new impeller along with piston ring plus in neutral comes out fine its just stops when above idle in water on boat so not sure why? ourboard guy says it pumped fine under load in his tank but maybe I should test in my bin?

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

I ran engine in a plastic bin of water, it was fine even under load, I don't understand why it would not be ok on the boat? The design the boat is based on is a clinker so it does widen in middle and seems to sit lower, how could i easily lower the engine some more? Could it just have been a piece of weeds or something that has now dislodged? I don't get why it wouldn't work on the boat in forward over idle but works fine in neutral? Could the middle of the boat be pushing water in a way that disturbed the pick up? Something strange about it, has anyone heard of similar? I think if i try trade in for a long shaft it will look odd on my little boat

 

[capttwb136]

Re: Mercury 3.3hp tell tale problem

Check the thermostat.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

Check the thermostat.

Sorry if this is a dumb question but how would I do that? When I ran at the weekend anything over idle on the boat and the engine stopped peeing and was just pushing like steam and exhaust fumes, if I put into neutral it would pump fine, so I tried in a bin of water and it was fine even whilst in gear with prop turning at revs, what would I check for the thermostat please? Is it possible thermostat could make a problem like this? Should I just retry on the boat and see? I asked the outboard guy who did all the work and he said could not think of anything other than too short for the boat or maybe weed in there?

 

[ondarvr]

Re: Mercury 3.3hp tell tale problem

There is no thermostat on this motor.

 

[ondarvr]

Re: Mercury 3.3hp tell tale problem

If the transom is wide enough move the motor off to one side and try it again.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

If the transom is wide enough move the motor off to one side and try it again.

I had already moved it over on its plate last week but it comes to an edge, it could go further over but would not sit on a metal plate, maybe I can try putting something there to clamp to like some card to make sure it doesnt mark the boat and try it again to see, if not do you thinkit could just be this engine does not suit the boat? Have you heard of engines before that pump water just fine but not wholstinmotion? Sure this problem could only happen to me I may try to exchange it in an get another one but I don't think it needs a long shaft it wouldn't make sense as it would be sitting too low.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

I have tried the engine again on my boat today, when it is running in gear above idle speed the tell tale starts to heat up and splutter out water and then stops, reduce revs again its fine, it seems to be when there is water moving against the pick ups it does not have enough suction to pick up for some reason, I also tried it in a bin full of water and it work fine it seems to be when current is running past it doesn't have enough to pick up with the water going past it, I moved it all around the transom it is certainly deep enough it just seems the propeller and water motion somehow seems to make it not able to pump it up correctly. Please can anyone help me with it as this is driving me nuts!!!

 

[ondarvr]

Re: Mercury 3.3hp tell tale problem

I had a similar problem with a totally different brand of motor and it turned out there was a poor seal at the base of the water pump and as the water level on the pump area changed it would start sucking air. Had to remove the whole thing and resurface the seal area, that fixed it.

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

I had a similar problem with a totally different brand of motor and it turned out there was a poor seal at the base of the water pump and as the water level on the pump area changed it would start sucking air. Had to remove the whole thing and resurface the seal area, that fixed it.

thank you very much, most.people ive spoken to never heard of this problem, so last night I took of lower unit undone it all, I've never seen a used impeller before apart from the burned one that came out 8 months ago, anyway so this impeller had the fins bent over a little at the top, not sure if they are supposed to be like that? Also like an idiot I left it on its side and lost the gear oil somehow must be some lubrication hole under the base of the pump? There was a bearing under there at base of the shaft, so which part should I be trying to make good seal? When you say resurface how do you mean please? I am guessing they don't use a gasket sealer on these as there no sign of it, I did have another thought though, is it possible the impeller fins are bent the wrong way? So when it spins it is not spinning as freely as it could? If you get what I mean so impeller fins are bent over towards the direction its turning, which would explain why it would be such a rare problem? I think I may also order another impeller, quick silver one to make sure top quality, how will I know for sure which way the fins should be bent to fit inside the housing and form a good seal? Thank you so much for your advice, I tried to contact the outboard guy who I paid to do the work but he is not replying so it may.look like I have to sort this myself

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

Hi there, do you think I need something like this? MERCURY MARINER OUTBOARD ENGINE IMPELLER PUMP KIT 3.3HP 2 STROKE PN 16159A2 | eBay

I believe will also need some gear oil as I lost some in my inexperience not realizing that the oil would come out of the gearing when the impeller housing was unbolted, tut tut rookie mistake

 

[Jon7]

Re: Mercury 3.3hp tell tale problem

Hi guys, still having problems with this, had engine checked again in another outboard workshop test tank, he said the motor seems fine, suggested it had to be the ridge at the stern pushing the water away and creating an air passage so it sicks air when you Go faster, I am inclined tobeleive this chap was far more helpful than the last, so here's my dilemma, I've already spent a lot more on this than I wanted to and theory is the engine is great condition now for a long time, so does anyone think trying to cut down the transome would be wise? Or is there some Type of adapter plate could use? I've noticed something called a jack plate seems to be to do with bigger boats and engines? Here is the link to the pronlem again, does anyone agree that center ridge could be the problem? I would hate to start cutting the boat about and then not even fix the problem! https://skydrive.live.com/?cid=41D8FE840AACFEB8&id=41D8FE840AACFEB8!126 thanks for any advice