Need help (Any Boaties out there that know engines

redback11, Oct 9, 8:47pm
I have a 2 stroke johnson 4hp for my tinny. Does any one have an idea what a full service cost. Cheers
m16d, Oct 9, 8:53pm
Do it yourself. New plug,. and change gear oil.
frank1, Oct 9, 8:55pm
Whats the prob!--I always serviced my own--anyway what year is the motor!
redback11, Oct 9, 9:02pm
Bought of a mate of mine went fine on sale when out in the water it started to conk out. Had stale petrol tho. Then replaced it with knew stuff and wanted to kick over but wouldnt. Broke pull start cord also want to know how much to fix aswell. But want to have it checked over thats why i just wanted to know how much it may cost. Cheers
redback11, Oct 9, 9:03pm
Johnson 2 stroke 4 hp. Not sure of age
intrade, Oct 9, 9:48pm
do it your self if you pay your likely just pay for nothing like my naigbour did full service 350$ and nothing nada was done for real engine overheated 2 month later and even spyder webs where there when she picked it up from the expensive service.
nicolerose, Oct 9, 9:53pm
drain the carb
frank1, Oct 9, 9:59pm
OK--guess it would be 70s-80s motor,pull cord to replace is not a major,would suggest prob is in carb or connection to fuel tank--ie sucking air and starving fuel.--just my views from outboards I have owned.
Another thing--have u got fuel mix right!
nicolerose, Oct 9, 10:00pm
give it sh.t
bigracket, Oct 9, 10:14pm
Dirty fuel for sure, carb needs to come apart and be cleaned. RULE 1 = its the fuel LOL
bm4, Oct 10, 5:38am
go do a small boat course!
stale fuel
fuel ratio correct!
mm12345, Oct 10, 6:51am
For servicing - apart from what others have stated, change the impeller. (probably $30-40) and check that the pump housing isn't worn out.
You have to take the lower unit/gearbox off the leg to do this, it can be a b@st@rd to get bolts free, and don't forget to disconnect gear linkage.Pack bolts with grease when reassembling.If the bolts won't budge, use heat from a blowtorch to free them.
Also, I'd be taking the thermostat out, cleaning it and checking that it's opening/closing properly using hot water in a cup, and replacing it if it's a bit dodgy.Sometimes it's a guessing game finding out where the thermostat is in small outboards.
Change the plug.If there isn't a sticker somewhere telling you which plug to use, google or ask a dealer - rather than just replacing with the same plug that's in the motor.People do crazy things.
When you change the gearbox oil, check the old oil for water.A little bit of milkiness is okay, but if it's really opaque / white or there's droplets of water in it, then you probably need to replace either the input shaft seal (under the water pump) and/or the seal(s) around the prop shaft.Prop shaft seals usually get munted first from fishing line getting wrapped around the shaft and tearing the seal out.
With the motor on a stand, fill the gearbox by squeezing oil up from the bottom drain hole until it starts coming out the top hole.Don't over fill.
As for it conking out after running a while, then as others state, it's probably old fuel.If it's a model with built-in tank, check that the breather in the cap is working. If it's got a separate tank, check the state of the seals around fuel hose fittings etc.
dave653, Oct 10, 12:56pm
Buy a book! I just did for my 4.5 and 7.5 Mercs, amazing what you learn. My 4.5 wasn't running right, eventually found a split diaphragm in the fuel pump, replaced with a good one. what a difference!
crzyhrse, Oct 10, 2:10pm
Post the code off the transom and I'll tell you.
owene, Oct 11, 8:46pm
Dump it on TM and get a new Merc - 3.3HP $600 if you look around. Then, you got a warranty, no problems with someone elses junk, no risk to your life at sea and a nice new motor.
gadgit3, Oct 11, 9:00pm
2008 Yamaha 2 stroke 30hp Full service including new water pump and carb clean $150 at the local boat shop. 4Hp I would imagine alot cheaper
owene, Dec 31, 2:57am
Yep, 4/30ths of $150 is $5/hp so it should only be $20. Cool.