Mariner 100hp bogging on top end

[vucelick]

I have a 1996 100hp mariner that will not take full throttle, it jumps up and goes but if you keep the throttle wide open it kind of misses or bogs slightly until you back off of the throttle setting a bit. I just got the boat last night and it has not been run since he put it away for the winter.

 

[vucelick]

Re: Mariner 100hp bogging on top end

Just a thought what portion of this could be bad gas?

 

[Scottj25]

Re: Mariner 100hp bogging on top end

You might want to test the pump ball on the fuel line that's located on the fuel line,maybe leaking in air if it has on. If not check for cracks and loose fitting in/on the fuel line maybe sucking air, also check fuel filters.

 

[vucelick]

Re: Mariner 100hp bogging on top end

I checke the ball/lines today everything is fine. I drained the gas completely form the tank/lines/carbs and refilled with fresh gas, this seemed to help a bit but the engine will not run at WOT, it kind of "flattens out" I changed props from a 19 to a 21, but saw no difference in top speed or engine performance it still "cleans out" when you back out of the throttle a bit. Any more ideas? It does look like the previous owner had the carbs off and/or serviced as the paint on the mounting bolts is nicked up a bit on them.

 

[jgreen5120@msn.com]

Re: Mariner 100hp bogging on top end

Hi Mark, I am having the same problem with at full throttle with my 175hp Johnson Sea Max (81)<br />I plan to check the fuel bulb/filters/pump today for any cracks. If this doen't work the guy I know at the Marina said to try a carb cleaner. Because my engine is a little older I am thinking there may be some carbon build up on the rings. So I may try an additive that is suppose to clean the rings. I will let you know over this weekend if any of these things work. It is just frustrating because it seems like I should be getting a lot more top end power/speed our of a 175hp engine on a 19.5' boat. Good luck, keep me posted.

 

[Scottj25]

Re: Mariner 100hp bogging on top end

If all the lines and primer bulb are and no air leaks, then you may be looing at one or more of the carbs. being in need of repair.<br /><br />You might check if there is water in the bowls(?) of the card.<br /><br />The fix it in the can almost never works if the motor or carbs. are in need of a rebuild. Did you check/change your filters yet? Just a thought is the stator advancing? you might want to check if its hanging up.<br /><br />Hope this helps.

 

[vucelick]

Re: Mariner 100hp bogging on top end

I changed the filters, and tried carb clean as recomeded by my local mechanic, he also said that there maybe carbon in the rings, but i tried it and it did not make any difference, the motor is a 1996. Like I said I completely drained the fuel system and lines and carb bowls. Should I try to service the carbs myself? I have quite a bit of experience with multiple carb setups on motorcycle and have sync gauges and other carb tools. Does anyone know the procedure for setting up these carbs? Or should I just pay my local mechanic?

 

[vucelick]

Re: Mariner 100hp bogging on top end

How do i check if the stator is advancing?

 

[vucelick]

Re: Mariner 100hp bogging on top end

Well, I checked everything else including the stator, everything seems to be ok. Is it possible that some dirt has got into the carbs, I changed the filters, but that does not mean that some dirt was already in there. Also, does this motor have a rev-limiter? I wnet from a 19 to a 21 to a 23 and can still exceed the 5250 RPM redline set by the manufacture, teh boat still launches out of the hole and hauls on top, but will not run at WOT cleanly. Now I have started to notice an erratic idle and when you pull the throttle closed the motor does not idle down smoothly, it sputers and chuffs.