25hp 2stroke merc questions?

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scoobeb

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Well i just sold my 2011 15hp stroke yamaha for $1800 which is $400 less then i paid for it,then went out and bought a 2003 25hp 2stroke merc in near mint condition.I have a question about the tiller.It is very loose as far as going up and down almost like there is a washer missing between the tiller and the motor itself.Can that be fixed by a dealer?I wouldn't think it would be an expensive fix.Also i have 2 new spark plugs that are made for this motor but i over gaped them by a hair.The specs call for .040 and they are closer to .045.

My dealer said it won't hurt anything but i just wanted to make sure from some of the smart outboard users here.Will it be a problem?These 25hp 2stroke mercs and yamahas are hard to find near mint and when u can find one jump on it.They are also getting very pricey because people know there is none left to get.I paid a little more then i wanted to but it will be a good investment for a long time.

Any help on the few questions would be great,thanks.
 
Tomorrow I'll look at mine to see if I can see what your problem might be.I have a 2000 25e Merc.Great motors.
You'll be ok on the gap.
 
I know most motors get worn down after some use.The guy claims it has only been used under 100hrs which isn't much on this type or any type of outboard.The compression was a dead even 120lbs.I mean it has a few little things like the rubber around the cowl is dry rotted in some areas which is no big deal.Down the road i'm gonna get a new cowl for it.They are fairly cheap at around $250ish my dealer told me then i need to get new decals for it.The power head is clean as a whistle.

Plugs looked good and the motor pumps awesome water when it gets warmed up.He just replaced the water impeller and lower unit oil so that is good for a while.I wanted a manual start not electric start.It pull starts like a dream.I can't wait to try it out on my 14ft jon boat i bet it will fly.I got 20mph with my 15hp yamaha with 2 people in the boat so i would say an easy 25 to 30mph with this 25.

I really hated to get rid of the yamaha but i feel this was the right move.The only smal issue i have like i said is the tiller being so loose when it should be tighter.I am almost positive a plastic washer is missing from in between the tiller and the motor.
 
I have this motor and love it. My tiller handle is a little loose too, but being that it's my first boat I don't really know what it's supposed to feel like. It doesn't really bother me.

I've got it on a 14' gregor and it does real well on the lower colorado river. Lots of power. I haven't checked the speed on it yet cuz I didn't have a way to measure it. Now I do, so we'll see in a couple weeks when I take it out.

Only problem I have is that it's a long shaft on a short shaft transom. So my weekend project is to put on a mini-jacker. I was debating swapping it for a short shaft, but it's such a great motor I'd rather not.

Can't help on the plugs though. It's so new to me I haven't even changed them yet. If you are concerned, just buy some new ones. They're only a couple bucks.
 
Just looked at my tiller & its quite snug.Don't see what could be loose on yours.
120 lbs. compression seems a little low for a low hour motor.Mine has 150 in both holes.Make sure when you do compression test you have carb wide open.
I'm quite familiar with these motors as I use to race them.
If your looking for a cowl I might have one.
 
I have had a few of these motors slip through my fingers because i wanted to try the 4stroke thing and i just keep coming back to a 2stroke.I can tell you that i have had 3 of these motors not as good as this one so i sold them but this is a keeper.The compression on the other 2 was exactly the same 120 on each cylinder so i'm not worried they are dead on.From what i understand as long as they are within 10% of eachother it's perfectly fine.

I just tested my brand new 2011 yamaha before it was sold with less then 5hrs and both cylinders were at 120 also.Well i guess we will see how she holds up.Also when you say the carb open just push the carb open and then do it?
 
Also when you say the carb open just push the carb open and then do it?

Yes

I looked at many motors before I bought mine.Those motors have a chrome bore.When they're worn out you buy a new block.
 
Well thanks for the good advice.I think this motor will hold up just fine.I will do a compression check one more time like you said.I was always taught as long as the cylinders are with in 10%of each other that was fine.I don't know a ton about motors just the basics like compression check and all the tuneup stuff.As far as internal i need to learn.

Please don't think that i'm saying you don't know about these motors but just for kicks i called mercury and i'm sure their not the smartest people there,i asked one of there techs if a 120lb compression was off for a 25hp merc and he told me it was fine.Like i said who knows if he's right but you got me a hair bit nervous saying the compression should be higher.I have had over 10 2stroke motors from like the last 15yrs and from what i have seen on my compression guage they were usually around the 120 to 125 area.

I will do a compression check today with the carb open to see if i get a different reading.

Also with the tiller there seems to be a plastic black washer that is missing between the 2 metal wahers or spacers to tighten the tiller arm up.Anymore info if anyone has some please chime in,thanks.
 
Here is a parts diagram for an 03 25hp. I'm not sure if it's exactly like yours but you can probably find it here if it's different than yours. It should allow you to compare parts to actual and determine what's missing, if anything.

https://www.crowleymarine.com/mercury-outboard/parts/4404_140.cfm
 
That is not the same motor i have,that digram is for a 25hp sea pro which is a rebagged tohatsu or nissan.I have the black motor(considered as the classic) with red decals on the cowl,also my motor has 400cc's unlike the sea pro which has 430cc's.They have 2 totally different tillers.
 
Go to the link, click "parts catalog" on the left side of the screen, and enter the appropriate info to get the breakdown for the motor you have>
 
Well i went to my local marina today and it is gonna be less then $100 to get the tiller like new.The labor is over $100 an hr but since i bring them the stuff i can't do to them for the past 15yrs they cut me a break to $75 an hr.The parts are like $20 to completely re do the tiller as far as making it tighter.It's missing 2 washers and they sell them in a pack of 4 so their going to take it apart and put all new washers in it for me.Now all i need is a new prop and i'm ready to fly.

From what i gather most people seem to use a 13pitch as it seems to be the best all around for everything,hole shot,speed etc....

Anyone have a good aluminum prop they can suggest is really good or they will all perform the same.I figured to get a new quicksilver at my marina for $95,seems like a fair price.If anyone has an extra cowl in good condition please let me know.The one i have is ok but the rubber around the bottom is getting rotted out.I may just buy a new one as i priced one for $269 at my marina and i need to get the decals also but that is down the road as the one i have will be fine for a while.

Man i can't wait to see how fast this thing goes. :D .I got over 20mph with my 15 so the 25 should do really good.
 
Well got my motor back finally from the marina.Not to bad,$72 to fix the tiller like new and tight like it just came out of the box.The tiller has a number of plastic washers and bushings in it and for some reason it was missing one plastic bushing that was a whole $9.

She is almost ready to go,just need to do a spark plug change,get my 6 gallon tank going(Speaking of gas tanks is a 6gallon tank big enough for this 25hp or should i go bigger?How many miles could i expect to get from 6 gallons of gas with mostly wo throttle with some slow speeds in between.Does anyone have some input on this?I know my 15hp didn't need much gas as a 3 gallon was plenty.

I am gonna head out on the water monday.I'm pumped to get some fish and getting to my fishing holes fast.Well i f anyone has some input on the gas tank size please let me know ,thanks
 
Well that seems like i would get close to 42 miles to a full tank from what u wrote crazymanme2.I guess i will do trial and error with the six gallon and if i need to go bigger i will go with a 9 gallon if needed to down the road.I have one of the last gas tanks before the new epa tanks are in.My 6 gallon was only $26 now they are no lessthen $50 and that is from walmart.Man i saw the new gas lines at walmart and they were get this $48.Wow that is nuts.I work at wally world so i get a monster 10%discount :roll: .Better then nothing i guess.I have a ton of new gas lines from the old batch not this new expensive stuff.

It's crazy how much money it costs us little people to fish.Just for a tank and line your looking at over $100.The government needs their money.Oh well need to get some sleep i have a long day of getting the boat ready.Thanks for anymore input on gas tanks.
 
Well i did my full tune up today.I put new spark plugs,new lower unit oil and a few extra things like greasing all the spots and a new fuel filter that is on the motor itself.

Well i have 2 small issues i need help with.

The first i know these run on a thermostat,but is it normal when it first comes on to dribble for a while like a few minutes then the water was coming out strong like it should.Does it need a few minutes to warm up before it spits water hard.My yamaha would spit it out hard from the start so that is why i'm asking if this is normal.

Also i know the knob controls whether the idle is high or low but when this motor was running it ran awesome but i can judge by hearing the motor it just sounded like it was idleing high even when the choke know was at its lowest.Do these 25 merc 2strokes just idle high as a norm or after some use and a good warm up it will go down.It ran good don't get me wrong but the idle seemed a bit high.Any info on this please?
 
Well i fixed the rpms today and knocked it way down with a few turns of the idle screw.Now i need to just hook up the water/fuel seperator on the outside of the boat and i'm ready to go.
 
The first i know these run on a thermostat,but is it normal when it first comes on to dribble for a while like a few minutes then the water was coming out strong like it should.Does it need a few minutes to warm up before it spits water hard.My yamaha would spit it out hard from the start so that is why i'm asking if this is normal.

That's normal for Mercs of this vintage.Mine does the same thing.Still not used to it. :oops:
 
You realize that you turn your choke knob to adjust idle also [-X

It changes your timing not your butterfly in you carb. #-o
 
I changed the choke knob 38 different ways and for no go for some reason.Every merc i have ever owned the choke knob always knocked down the idle but not this one at least not enough.The idle screw was way to high and as soon as i gave it a few small turns it was perfect.I got the idle way down like it needs to be so i can't do any damage to my lower unit.Now i got me some ethanol free gas and i'm ready to roll.I love the sound of reving this motor it sounds like a racing car compared to my little 15 yamaha.You can just feel the power of this motor you know what i mean.It's built for power and speed.Well i will let you know what my top speed on my gps with me and with me and a buddy.

It will probally be simillar,maybe a few mph difference.I love yamaha's but the merc 25 just takes the cake for all the 25's i have seen for overall power and top end.I called merc a few yrs ago and talked to a tech about these motors and he even told me if you can get your hands on a great merc or yamaha 25 get.According to many people who i have talked to if it is true or a myth who knows that almost all merc 2strokes are more powerfull then advertised.I was told by a tech who has been with merc for 27yrs the 25 is more like 33hp,if thats true who knows.
 

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