mercury/150/v6 no power

[pete petterson]

have had motor worked on 3 times and repairman can't get it to work in the water as will as it does on shore.problem is that when you give it some, up full throttle it just boggs down and runs like a trolling motor. as i said it runs great on shore when hooked up to tester that they use(like its in the water). but all three times same thing happens. tried of going there. please help. thank you in advance.

 

[kenthrussell]

Re: mercury/150/v6 no power

Hi I had a similar problem providing your compression and everything is fine,I have a 200hp v6 merc and had some trouble that sounds the same as yours it was dirt in the carbs which would not let the needle valves seat which caused a flooding condition,the problem would not show up until after about 10 minutes of running.I took the carbs off cleaned them up as there was already new kits installed and installed an inline filter after the tank and before the primer bulb.For a test in the water or idling in your drive way with the muffs on remove the cover and the attenuator(covers the front of the carbs)and let run if you see gas running out of the front of the carbs this is your problem.....hope this works good luck!

 

[pete petterson]

Re: mercury/150/v6 no power

thank you for the reply. I will try that fix and see what happens. Thank You again KentRussell<br />

 

[pete petterson]

Re: mercury/150/v6 no power

dirt in carb doesn't seem to be the problem. Still runs great hooked up to dyno on shore, but in the water no power.Replaced something called(maybe mispelled)stater (not starter) .reason for this it was starting to lose power on the water. told this would help and it has not. that is why i posted this question Kentrussell tried to help but I'am Back.still thanks in advance for help or suggestions

 

[hondon]

Re: mercury/150/v6 no power

OK . Since this engine will perform well on the DYNO but not on the water ,we might start looking into an exhaust restiction.Checking this possibility out is a little invasive ,so some info is advised.Do'es this thing idle for most of the time espcecially in cold water like on a house or patio boat?What kinda oil are you using?The point I'm trying to make is that sometimes a big ball of carbon can build up in your exhaust horn and create your symptoms.Good luck.

 

[pete petterson]

Re: mercury/150/v6 no power

HONDON. THANK YOU FOR THE REPLY. regarding useage of this motor, we use it on a bass boat in the delta(california).We changed it over to hand mix,(gas and oil), couple years ago. cost factor. You may be right on target but we don't have the skill to be to intrusive in this motor or any other. That leave us looking to find a better tech, but at least we have another direction to look in. We may become a little adventurious and take a crack at it anyway... Thanks Again for your responds much welcomed... pocketpete.....

 

[clanton]

Re: mercury/150/v6 no power

Run 2 cans of engine tuner thru the engine, engine tuner will burn carbon out. Will it hold 5000 rpms on dyno for 5 minutes.

 

[pete petterson]

Re: mercury/150/v6 no power

Clanton: thanks for your reply. Yes it does hold 5000rpm's on the dyno,that's what has us when we go out it can't get passed a slow troll speed no matter what we do. So we will try your suggestion and see what happens. We are still looking for a good tech.. When we get the answer to this problem we will post results to this forum or any other forums that someone suggest. thanks to all three of the responders. It,s great to know there is help out there, a couple clicks away thanks KR,HON,and CLAN.

 

[rlouns]

Re: mercury/150/v6 no power

It probably would not hurt to check the wires going to the coils. If they are breaking (but not completely broken yet) they will break down under a load and cause a loss of power. Check them by pulling on them (they can be broken inside the covering).

 

[Jomusky]

Re: mercury/150/v6 no power

This is my first time to this board. I am impressed and will be back often. Anyways, I run a 81' 175Hp Merq and have had simillar problems. <br />One was a bad ground to one of my coils. The problem was intermitent and very hard to find but easily repaired. Not sure if you have the same ignition system but if you do check all the ground straps and conections.<br />The other was just last year and it was a bad wire in the ignition trigger(not sure if that's what it's officially referenced by). The symptoms were also intermitent and would only show up when the motor was throttled. When throttled the trigger is rotated for timing advance and the wire would open. The way I found it was by having my wife throttle the motor while I wiggled the wires. All of a sudden when I wiggled the right wire the missing cylinders fired and almost threw me out of the boat. <br />Hope this may help you.

 

[JB]

Re: mercury/150/v6 no power

Hi, PocketPete. I have been following this thread, but didn't have anything new to offer until now. <br /><br />When you run this engine ashore, are you using everything that you use on the water? I am thinking fuel, tank, hoses, primer bulb.<br /><br />When you run it ashore, do you have the bonnet on it? Exhaust leaks have been known to strangle an engine that runs fine with the bonnet off. Also, the bonnet has been known to pinch hoses and short out wires.<br /><br />Hope that helps.<br /><br />Red sky at night. . .<br />JB

 

[pete petterson]

Re: mercury/150/v6 no power

yeah its me again.will i tried some of the tips to no fix. went to another tech up the road and he found that the stater was put on with long bolts to help keep it in place. problem seems to be that the bolts block the the vaccum advance from working this maybe it have not got to the water yet. put he is confident that is the fix we'll see.thanks again to this forum and the following ship mates Kentrussell,Hondon,Clanton,RobertL,Jomusky,JB Cornwell. thanks a lot see ya. Pocket

 

[prosise]

Re: mercury/150/v6 no power

you possibly are running a bit lean. After the engine heats up it will start to loose power. Also, what prop are you using? You might be propped wrong, too much pitch for your engine will cause the same thing, loading up... Like starting off in 3rd gear in your truck... Just a thought, my boat is propped for speed so its slow out of the hole but good at high end. <br /><br />Prosise