How To Service - Mercury Mariner / Tohatsu 30hp 2003 2 Stroke Outboard - MA30ML / M30A4

[@rogerpaice4806]

An Extremely comprehensive explanation with additional mechanical advice that applies to all small to medium outboards 2.5 hp - 30hp & comes from good training and experience, follow this advice you will stay safe and enjoy trouble free sea-time. Thankyou - RP UK.

[@MarineEngineServicing]

Thank you very much! 🤙

[@brettgoodwin3422]

A good, concise video. I like how you take your time and cover the lot. I had trouble with the gear linkage on mine and didnt even think of using penetrating oil. I gave up as I thought I would break it and ran the impellor another year. Ill try your way now. Cheers from Australia

[@MarineEngineServicing]

Thanks for the kind words 👍 Glad you enjoyed the video

[@alangranton9601]

Great video. Thank you for taking the time. Have you worked on Tohatsu TLDI engines? Mine will need servicing and winterising in October.

[@MarineEngineServicing]

Servicing is pretty much universal, once you’ve done a few they mostly follow the same standards. Obviously there some exceptions and differences between manufacturers, cycle type or fuel delivery.

[@age.8599]

Hi there great video ! I have the same motor , experiencing good running for a while then cuts out is hard to start sometime just fires back up, replaced spark plugs , suspected carb or fuel issue ? Do u have video for carburetor service ?

[@MarineEngineServicing]

Thanks for watching and enjoying, at the moment I don’t have one for this specific engine. But I do have videos on carbs for other engines. Easiest thing would be to use some fresh fuel and try that ( cheapest option ) A carb clean especially on the the idle / pilot jet. Sometimes with the engine running you can hold the palm of your hand over the carb intake and this creates a massive vacuum which can sometimes clear the carb if it’s partially blocked. But really the only way to fully clean it would be to take it apart. Some carbs have a float bowl drain screw which can be taken off with out having to disassemble the whole carb which can drain any muck or water out the bottom. Could also be a weak fuel pump not delivering enough fuel to the carb which then cuts out due to fuel starvation. Then you pulling the motor over re primes it. Again this can be rebuilt or replaced

[@scottroberts7962]

Hi, just after some advice please! I have a mariner 40hp 6e9. It starts up but the pull cord is really hard to pull out sometimes and sometimes comes out smoothly? When it’s hard to pull it’s almost like it slips a bit then starts then slips a bit. Any advice would be appreciated. Cheers

[@MarineEngineServicing]

Hi, sounds like it could be the recoil starter, that’s where I would start. I believe it can be removed with a few bolts. Maybe needs some WD-40. When you say it slips it could be down to worn prawls which engage on the flywheel, these then retract when the engine is running / recoil is stopped. They fly out when the recoiler is pulled hard and should engage on the flywheel

[@traciewarren915]

just what i needed have mariner marathon this video helped a lot ,same outboard looks also like a tohatsu could you tell me how many splines on the prop . , big thanks help me put the new HT leads to the correct cylinder ,i took them off before i went into hospital and forgot what lead went where so bought new leads and gave enough lenghth so i could swap them over if i got it wrong thanks again bun

[@MarineEngineServicing]

Glad you found the video of some help 👍 I believe the spline count is 10 on this engine but I’d double check, I don’t have access to the engine anymore to check for you.

[@thahay5353]

Any advice for if the gear selector shaft won't separate at the sleeve?

[@MarineEngineServicing]

Heat and penetrating oil

[@thahay5353]

That what I thought, have tried penetrating oil and freezing but not heat yet

[@MarineEngineServicing]

@@thahay5353 only other thing to try in addition to heating the collar up would be to use a pair of grips top and bottom and try to “pull” the parts apart. You might be able to twist slightly as well but I’m not sure how much twist you’d get due to alignment

[@ClintMicale]

Great vid thanks mate

[@MarineEngineServicing]

No problem 👍

[@tezzzier]

Great Vid thank you!

[@MarineEngineServicing]

Glad you liked it!

[@MrSealife64]

Nice work but there is still lots to be improve. Take flywheel off and make a rebalance and the engine will run smoother.

[@MarineEngineServicing]

Thanks for the tip

[@MrSealife64]

I did that to one of mine

[@thegunnut221]

Great video . But man that engine really needs some spray lube to stop any further corrosion on all those bolts under the cowling.

[@MarineEngineServicing]

Thanks for the tip 👍 I usually spray the block down with WD-40 or light oil

[@trustthedogsheneverlies644]

LPS works great too and you can select a viscosity you like. It sticks around for longer IMO :)

[@andrewlewis9255]

Hi there, i have the same engine (mercury version). my motor pumps a lot of water out of the upper exhaust port with a little less out of the tell tail than yours. i have spoken to my local mercury guy and he said its normal with these engines however yours does not do it. any ideas as to what causes this?

[@MarineEngineServicing]

Hi, If you have a good flow of water but not much coming out of the tell tail then it could be a blockage on this rubber hose. I would remove the tell tail hose and clear it, could be dried salt or sand etc. With the pipe off ( or proven clear and back on ) start the engine again and see if you get more water now. If not it could be a packed water jacket or at least the lower section of it. This will need clearing with the exhaust jacket plate off. Also check your thermostat housing for sediment build up and also a good time to check the operation of the thermostat. The tell tail isn’t the end of the water cooling path but an indication of cooling water. So it blocked doesn’t normally mean a failed water pump etc. But it’s a very good way to show water flow. Hope that helps 👍

[@andrewlewis9255]

@@MarineEngineServicing thanks for the reply. It is definitely not a blockage in the tell tail tube. That is clear. I’m not sure what you mean by a packed water jacket? I will have to google that one. Is removing jacket plate and clearing as you’ve mentioned much of a job? I will check the thermostat and test as you’ve have in this video.

[@andrewlewis9255]

Think I found the problem. The thermostat is quite corroded and was stuck open

[@MarineEngineServicing]

So normally where the tell tail hose is pushed onto the barb fitting, that cover is the exhaust jacket cover or cylinder jacket cover where cooling water fills etc. normally the cover is held on with a few bolts and a gasket. Sediment and salt can settle and dry there causing a blockage of the tell tail. If you’ve got water coming out of it you should be ok.

[@MarineEngineServicing]

Good shout on the thermostat 👍

[@ΚΩΣΤΑΣΒΟΥΒΟΥΤΣΗΣ-κ7ω]

Πώς βρίσκουμε τα σημάδια για το αβανς;; Ευχαριστώ ωραία δουλειά !!!

[@MarineEngineServicing]

If your referring to timing marks, it’s on the left side of the engine under the dented flywheel