2001 Merc 25hp..tiller

[Decoy2]

Hello,<br />Just found the site today. Great site. <br />I've recently had issues with my 25hp merc...here goes..I let it sit up from May 05 til Sept 05, (I know this is not good) so I had to have the Carb rebuilt by a local boat mechanic. Just yesterday was the first time that I was able to try it out, it started right up (would not previously do this) and ran for about 15-25 seconds... then shut off, I reached down and the bulb is pretty flat, so I pump it and it starts right back up, and again repeats the above situation. So I finally just started pumping the bulb and it ran like brand new..(as long as I pumped the bulb)...So any suggestions? I was told that the fuel pump is built in the carb? I guess there is no visual check, the mechanic could have done? Next, could it be the gas line/tank? Any easy way to test this, other than purchasing a new one?<br />Thanks for any help...<br /><br />Decoy

 

[Laddies]

Re: 2001 Merc 25hp..tiller

If the bulb is going flat then the fuel is being restricted in the line or tank on the tank side of the bulb, but if its not going flat and by pumping the bulb it runs alright its the hose connecter or fuel pump

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

It's not going totally flat but very close to it, but it does run just fine when the bulb is pumped...<br /><br />Decoy

 

[Laddies]

Re: 2001 Merc 25hp..tiller

Ck the tank pickup first to see it's clean, if thats not the problem ck the fuel pump

 

[Laddies]

Re: 2001 Merc 25hp..tiller

After finishing the last post I remembered that a few yaers back Mercury had some bad hose assm. that the bulb caused a simular problem to yours the ck valves in the bulb would stick sometimes

 

[inlineal]

Re: 2001 Merc 25hp..tiller

Amen to that Laddies..Merc bulbs gave us so much trouble back then we just flat stopped stocking them...Used nothing but Sierra products since with good results...Seems it was Mercury's 3GAL tanks that the pickup was too long and was makin a seal at the bottom of the tank..We were removing the pickup pipes and cutting off a half inch or so..

 

[rayjay]

Re: 2001 Merc 25hp..tiller

Make sure you have the gas cap vent open.

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

The vent is open.<br />Just to clarify from above, Should I try a new/different hose first or do you mean, modify the intake inside the tank? Thanks, I'll give these things a try today..<br /><br />Decoy

 

[ehenry]

Re: 2001 Merc 25hp..tiller

I'd try a different hose assembly before I did anything. Even if It doesn't fix it you'll have a spare if you need it.

 

[rayjay]

Re: 2001 Merc 25hp..tiller

Buy a new hose assembly and just stick the end of the hose down into the gas cap opening and see if the motor runs. If it does then connect the new line to the fuel fitting on the tank and if the motor starts acting up you know it's the fuel feed line in the tank.

 

[Wiggy]

Re: 2001 Merc 25hp..tiller

I had exactly the same problem just the other.....found out the ball bearing in the fuel connector had fell out thus causing the engine to suck in large amounts of air and no fuel. Check this, as I could only run the engine whilst pumping the bulb, and it had the same symptoms as you're describing.

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

Ok, bought a new fuel line, connected it to the tank...same result, still shuts off after the gas goes through the hose, so then I removed the fitting on the tank side and put the hose in the gas to rule out the tank, same results...<br />So, is the fuel pump (diaphram) the only thing left that it could be? I called a local marine today, they said around $45, is that about right?<br />Thanks for all the help!<br /><br />Decoy

 

[ehenry]

Re: 2001 Merc 25hp..tiller

In your first post you said it was sucking the bulb flat....right?? Do you mean the bulb is no longer round or that its not pumped up hard anymore? I may be wrong but if the bulb is getting sucked flat that indicates to me that the tank isn't vented like it should be. Laddies is the authority...what ever he says is what I'd do.

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

In a couple of post lower,I said that it was not totally flat...It is definitely not a venting issue, I even put the hose directly into the tank and started the engine like this, with the same result..So really, you are right, I should have said it was not hard anymore. I plan to get the diaphragm kit this weekend and try that, I'll post the results..<br />Thanks again for all the help.<br /><br />Decoy

 

[ehenry]

Re: 2001 Merc 25hp..tiller

Will the engine keep running while you pump th bulb?

 

[KIGuy52]

Re: 2001 Merc 25hp..tiller

My on-line parts source charges around $39+s&h for the diaphragm kit, so your dealer's price is reasonable.

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

EF,<br />Yes it runs fine while pumping the bulb..<br /><br />Thanks KI..<br /><br />Decoy

 

[Decoy2]

Re: 2001 Merc 25hp..tiller

Ok guys...I don't know what else to do...other than take it in to a professional...I replaced the fuel diaphragm kit, and the same problems occur...Here's everything I've done...<br /><br />Made sure gas tank vent is open<br />Replaced gas hose (fittings and hose)<br />Put gas hose directly into tank (to eliminate tank problems)<br />Replaced Fuel diaphragm kit<br /><br />It still runs great, if I continue to pump the bulb, while it's running...<br /><br />Anything else you guys can think of before I take it in?<br /><br />Thanks again..<br /><br />Decoy

 

[KIGuy52]

Re: 2001 Merc 25hp..tiller

Contact the Mastertech (Bill Kelly) at Maxrules before you take it in. He has paid on-line technical assistance and though it costs $20, it's cheaper than taking it to the shop. Tell him what you've already done. I bet he can tell you what's your problem is. This guy really knows his stuff.<br />www.maxrules.com

 

[andy6374]

Re: 2001 Merc 25hp..tiller

I'm inclined to believe its probably the fuel pump (even though you rebuilt it), let us know what the Mastertech says. I say this because by pumping the primer bulb you are doing the job of the fuel pump. I'm not sure on your engine, but the fuel pump usually uses the suction created by one of the cylinder during compression. Maybe that hose from the cylinder to the fuel pump is bad, hence getting no suction.