1999 125 Merc bogs, wont plane boat

[13lokei]

Having no spark on number 1 cyl I installed a new trigger and that took care of one problem. One problem that i cant seem to trouble shoot is a bad bog. The boat starts well ideals good but when i try to take off it just wont plane and is bogging badly. This is a 1999 125 hp merc elpto, all gas connection are good and anti siphone valve is not cloged. The fuel pump is working correctly and all cylinders are firing. One thing i noticed that is strange is the timing. At ideal its at 4 degrees ATDC, if i put it on 4 Degrees BTDC it wont ideal down and stays at 1800 rpms at ideal with carbs shut all the way down like they should be. The prop is same its has always had back when it ran great. Any ideas? Thanks

 

[xxturbowesxx]

Re: 1999 125 Merc bogs, wont plane boat

Bogging is usually a symptom of fuel delivery.. does it bog then if you take it past a certain point die? if so that may be a powerpack..Check and clean the carbs,check the tank or run on a portable tank,and check the lines for obstructions.. If it doesn't fix it then move to checking the spark..

 

[markfisher]

Re: 1999 125 Merc bogs, wont plane boat

i need help, got 1999 mercury 125hp,outboard, its little shaking on idle,a nd tachometer gage arrow on 4 (when it run on idle)
thanks

 

[markfisher]

Re: 1999 125 Merc bogs, wont plane boat

please , anybody if you reply to my messege, please send me private messege, because i dont know how to get back to this forum to read replies, thank you all

 

[xxturbowesxx]

Re: 1999 125 Merc bogs, wont plane boat

i need help, got 1999 mercury 125hp,outboard, its little shaking on idle,a nd tachometer gage arrow on 4 (when it run on idle)
thanks

This is what we call a Hijack and don't do it.. this is 13lokei's thread and if you want you question answered ask it either in your thread that already exists or create a new one..

 

[13lokei]

Re: 1999 125 Merc bogs, wont plane boat

Carbs seem to be good, Today I had the air box cover off and while my friend had it at wot i watched the carbs. Each carb had the same faned out gas flow. The boat even though was at wot was only doing 1800 rpms. Checked spark and all had a good spark with a 7/16 air gap tester. Advance timming was at 22 degrees at wot while cranking. Motor starts well and runns great ona hose. Gas was checked and no water all clean gas in tank. This is a mecury 2 by 2 its called where only 2 cylinders operate at idel. So with that being known i checked for flooding through the enricher valve and accelerator pump, all good there. Checked for vacum leaks and found none. Sync and link are right on. Boat is acting like it has a very over sized prop but it is same prop that always ran good before. It wont die it will just keep chuuging away at 1800 rpms with the boat nose in the air. 18' bass baot. Im out of things to check. Help please. Thanks

 

[13lokei]

Re: 1999 125 Merc bogs, wont plane boat

One more thing. The motor idels at 800 on a hose but jumps to 1000 for about 10 seconds, then drops down to 800 again and stays there for about a minute then repeats back to 1000 for about 10 seconds. This information may help you to help me. Thanks

 

[fasassvalk]

Re: 1999 125 Merc bogs, wont plane boat

Did you check pick up tube in tank to see if it is clogged ? Most have a strainer / filter there too.
I have the exact same motor you have, the other day I had done alot of idleing around through canals and such..
When I came out of the canal and planed all was fine , then it bogged completely down and shut off, water washed over the transom, I restarted it sat there and idled fine and took off and ran fine and up to now has not done it again. Lifes unsolved mystery ! hope it is not a sign of things to come.

 

[CharlieB]

Re: 1999 125 Merc bogs, wont plane boat

Idle speed is adjusted with timing, idle timing is not the issue in your bog. As long as the timing arm moves freely with the throttle and WOT timing is by the book then timing is not your issue. Unless you installed the trigger leads incorrectly and the firing order is incorrect.

Check it to be sure.

GENERALLY a throttle bog occurs when idle mixture is not rich enough to provide the additional fuel required for acceleration.

The 2 + 2 is a special creature, only the upper carbs have have idle mixture screws and must be set almost 1/8 turn out past 'Best idle in gear', this should be done on the water. The lower two cyl's have an accelerator pump to give this 'extra fuel' for acceleration as they do not have an idle circuit and no combustion occurs in them while at idle. The lower cyl's DO begin to burn fuel the moment the throttle is moved 'Off-idle'.

As long as the fuel system is clean and adjusted properly that may NOT be your problem.

You say that you have spark on ALL cyl's, which may be correct cranking and low engine RPM while the low speed windings of the stator provide most all the electrical power needed by the ignition system.

HOWEVER, 1800 RPM is within the transition zone of the low speed windings failing to continue peak voltage and the high speed windings begin to develop voltage. A fault in the high speed windings would 'spark limit' engine power and RPM.

You need to begin testing the stator.

Disconnect the stator leads from the ignition module and test with an Ohms Meter.

Reconnect the leads and test stator voltage with a DVA Meter. Test cranking voltage on each set, low and high. Retest under load when the bog exists.

Repost your findings.

Remember there is NO RETURN on electrical parts.

Test, Test, and Re-Test before ordering any electrical parts.

 

[13lokei]

Re: 1999 125 Merc bogs, wont plane boat

Ok this is what I have found. I tested stator with a ohlms meter. Its was at 780 ohlms which is 20 ohlms above the 760 max that the book tolernce is. I dont have dva meter so cant check that. Excelerator pump is now out, was working now isnt, maybe something there causing all this. Ordered one today.
What do you think about stator reading? Should i get anew stator?

 

[13lokei]

Re: 1999 125 Merc bogs, wont plane boat

One thing i forgot to mention. Ohlms test showed no ground outs, just little higher then tolerence reading on green white, white green wires.

 

[CharlieB]

Re: 1999 125 Merc bogs, wont plane boat

Ohms test is within 5%, HOWEVER, Ohm's isn't the most reliable method of testing any type of coil windings. It is possible to have a broken winding, the ends butted up together and give an Ohms reading well within tolerance, yet when a load is applied the butted ends fail and voltage falls off, limiting engine RPM and power.

NO, DO NOT order a stator yet, no return yada yada........

It is possible to test a stator without a DVA Meter, however you must NEVER try this on a trigger 'cause you will smoke it.

Disconnect the stator leads, rigg a jumper wire too the + battery terminal, connect your test light to the - battery terminal, hold the test light to the other stator lead. If the light lights and remains on then that set of windings is good. If the light fails THEN order a stator as the butted ends of the broken winding have failed to carry the load of the test light.

 

[sschefer]

Re: 1999 125 Merc bogs, wont plane boat

Check where the accelerator pump sends it's fuel when it's actuated. On mine it goes to injectors at the intake manifolds. If they are plugged then you will have a bog.

 

[13lokei]

Re: 1999 125 Merc bogs, wont plane boat

Charlie that was it. Stator failed test light check. Bought new stator and im up and running in time for this weekends tournment. Cant thank you enough.
Learned alot in the process. Thanks again.

 

[fasassvalk]

Re: 1999 125 Merc bogs, wont plane boat

please , anybody if you reply to my messege, please send me private messege, because i dont know how to get back to this forum to read replies, thank you all

Empty your message box, it is exceeding your limit and no one can send a PM to you