I have a 2000 18 ft, Bayliner with a 125 HP Mercury outboard,My problem is, if I am cruising along at approx. 1500 rpm's and i want to throttle up a little, lets say to 1800 rpm's. It just jumps up to 3500 or more with just a touch of the throttle, I didnt speak to a mechanic about it yet. But I was told by a friend that my outboard has 2 carbs. It runs on 1 carb at low rpm's and will kick in the other carb at higher rpm's. It appears to me that my throttle cable is hanging up and when I apply more throttle it releases, causing it to jump up to a higher rpm, I hope I explained this ok. I was wondering if any one out there has any info on this problem.
Would appriciate any info on this..
This is my first time on this site, I am not sure how to sign this or leave my Email add. Piscesstar@aol.com
Thanks Rock...........

Hang tight Rock, somebody other than me that knows about these things will be along soon to help you out. You might not want to put your email up on a public forum les you want spam. There's a personal message (PM) system available for that. If you go to "My Stuff" and click on "My Profile" you can put it there to get notified whenever somebody PM's you.

In the meantime, welcome aboard.

Most outboard systems I have been around have a "tension adjustment" near the user throttle handle. Have you adjusted the tension?

With my outboard, the effect you describe happens around 2500 rpms. I am aware of this when i'm trying to throttle in the "gray area".

A 2000 Mercury outboard enigne is nowhere near the advanced and user friendly stage that today's vehicles possess. Your engine does have some designed compromises.

If something can be done, someone will toss out other ideas besides tension adjustment.

"A 2000 Mercury outboard enigne is nowhere near being as advanced and user friends friendly as are vehicles engines area. There are designed compromises that are made to keep prices down. Just keep that in the back of your head."

Sorry, but I just had to make that more readible, D.

YIKES!

Okie, I edited it.

rock - welcome. i don't have any experience with outboards but i'm sure you'll get plenty of advice soon.

and don't anyone even THINK about correcting my grammar as i am hopelessly anti-semantic. in fact, i hope i spelled grammar right. i meant my writing style and that kind of stuff, not my mom's mom.

Sheesh, BT, anti-semantic? Let's keep that to yourself or the Friday night meetings around the fire, alright??

'Cruising' along at 1500 rpm is just barely above idle for an outboard...My '95 115 Mariner outboard on the Party Cruiser is an inline 4 with 4 carbs, the bottom 2 of which are 'dead' at low speeds, so I'm familiar with the "feeling"... Not sure, but I think you have a V4 with 2 carbs? At any rate, the second carb(s) will be right on the verge of kicking in at that speed, and just a nudge of the throttle can kick it, and it'll feel like a supercharger just came on (because you just instantly doubled your power!), and hitting 3500 rpm sounds just about right...

The question then, is: does it do this ONLY at or near 1500 rpm? Or at other engine speeds? If only around the 1500 range, I would bet it's perfectly normal (if not a bit frustrating!)

Rock never came back.

Yes I think that your response was on the money Farwarfloten, I do have the twin carbs. I spoke to a mechanic and he told me the same thing about the other carb kicking in abruptly. It is quite annoying. You have to be careful when you are in the gray zone. Thanks a lot for the replies.
Rock................
PS I think this is a great web site.

Not sure how the second carb is actuated but if it a "Cam and Wire" type it could be the cam is set to hit it high spot a bit prematurely. See if it can be rotated one way or the other on its shaft.

A good service manual might help, there are several publishers the put them out. Seloc is the brand I have used for my boat.

Did 'we' ever get this problem solved?

Sounds like the throttle linkage is hanging up on something (a snag) and then once it gets past a certain point it jumps to where t *should* be.

It could be either the throttle cable or the linkages/cables within the engine cowl.

Rock, come back and let us know.

Second carb kicking in

--if it's like my second TWO carbs, and I'll assume it is-- it's actuated strictly by air flow. My manual states that at lower rpm's, residual oil from the higher cylinders is enough lubrication for the lower cylinders, so they don't even put an idle circuit in the second carbs. And it's just a matter of when the engine is pulling enough air to draw fuel thru the carb to start firing the second pair of cylinders. Mine come in at around 2500 rpm, but I'm pushing 7000# of pontoon boat with a 13" pitch prop, so it's not all that "abrupt", but it's definitely noticible!

Thanks Guys. I really havent done anything to the motor yet, Ihave been so busy with other things that i have that problem on the back burners. I appreciate all the advise i recieved, So thanks again. This website is great
Rock.....................

I am thinking that at 1500 rpm the boat isn't on the plane yet and as soon as you give a few more beans it gets on the plane and then takes off. This being the case you will just have to get used to it. I have similar problem towing knee boarders just takes a little practice that's all.
Hope this helps
Ardy
South Australia