charging / lacks power in water 150 merc

[wrenchtrnr72]

I have a Merc xr2 150. It will not go on plane, but when out of water motor runs and revs great? In water i can only idle, motor boggs when trying to throttle up. I have checked voltage at battery, one day it was 12.7, another day it was 13.0 to 16.3(depending on rpm),today it is 13.0 @ idle and 15.0 @ higher rpm. I'm lost and dont want to buy expensive parts if i dont have to. And i dont have a dva meter, i have a high quality dvm. please help my family wants to go fishing?

 

[eurolarva]

Re: charging / lacks power in water 150 merc

The volt meter will not work in place of a DVA. AC signal is running too slow for it to be read on regular meter. Have you tested your compression? If not at least check your plugs. You are looking for slightly black oily plugs that look consistant.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

plugs are black and a little oily. boat runs like a top fuel dragster with water hose hooked to it, but in water wont get out of its own way?

 

[eurolarva]

Re: charging / lacks power in water 150 merc

You will need to check your compression. Auto parts stores and sears sell these for under 30 bucks. When you submerge lower unit you are creating back pressure which could be compression related. If not I would start looking at your ignition system. You are looking for compression numbers on a warm engine well over 100 and within about 5 points difference between cylinders. make sure all plugs are out of the cylinders, connected to wires and the plugs are grounded at the threads. Crank a couple of times to get a compression reading on each unit and post it here.<br />Also when you say runs out of water well I hope you mean with muff and the garden hose hooked up.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

all cylinders are 123 - 125 ish when running comp. check with all plugs out using a remote starter button.number 5 plug was clean and wet number 1 was black and kinda dry, 2,4,6,3 spark plugs were dark and oily.

 

[eurolarva]

Re: charging / lacks power in water 150 merc

Now test number 5 spark plug in a dark area and see what kind of spark you get. Is it blue with a snapping sound or yellow. If you get a good spark do this. Keep the number five plug connected to the test fixture that you are using to test for spark. Put a spare plug in the cylinder with no wire attached and see if the plug you are testing gives you a spark.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

ok, #5 hole sparks the same with plug in and with plug out? nice crisp blue spark.yes sir, i did use a spare plug in the hole after checking with no plug in the hole.

 

[eurolarva]

Re: charging / lacks power in water 150 merc

Well I gave it my best shot. Hope someone else can help you out. Please make sure you post what the solution was. I was sure it was compression and am pretty sure it is electrical but I would really like to know what it is.<br /><br />Good Luck

 

[Alexo1us]

Re: charging / lacks power in water 150 merc

This is just a guess but I have seen 2 strokes bog with two much oil and the plugs I have seen have the same black oily look to them. Is your Merc oil injected or do you mix it, how smokey is when it runs with the newer ratios there shouldn't be much smoke. Dosn't take much to get them revin on the muffs, but in water there is alot more power required oil could be causing the mix not to burn correctly. <br />Just a thought, maybe on the wrong track but I always try to rule out simple things first. <br />Alex

 

[highaltitude]

Re: charging / lacks power in water 150 merc

try choking the motor when trying to get up on plane-sounds to me like fuel-start with the basics. if you suspect spark use a timing light to check spark on each cylinder. kiss

 

[highaltitude]

Re: charging / lacks power in water 150 merc

post script----everything will run without a load.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

I run a ratio of 50:1 when it is out of the water it smokes some but not a whole pile.<br />Is 50:1 correct?

 

[eurolarva]

Re: charging / lacks power in water 150 merc

Here is a link for a DVA adaptor. Looks kind of sweet may have to buy one for myself DVA Tester

 

[KCLOST]

Re: charging / lacks power in water 150 merc

It's time for a carb rebuild.... Decarb might help also...<br /><br />Decarb first on the muffs, mix a gallon of pre-mix gas with a can of seafoam in a remote tank. Run the engine on the muffs for several minutes. You can also spray seafoam into the carb throats while running until it stalls. Shut down, and spray a bunch of seafoam into the cylinders and let soak. <br /><br />Then restart and flush the engine. Repeat a few times for extra assurance. It's going to smoke a lot just to warn you. <br />Take to the lake and test. If this doesn't help, do the carb rebuild. Good luck.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

Am I mixing it right? I have allready cleaned the carbs out.<br />Sometimes it dosen't charge right and sometimes it over charges.

 

[Alexo1us]

Re: charging / lacks power in water 150 merc

Originally posted by highaltitude:<br /> post script----everything will run without a load.

Only if they are running some what<br /><br />I'm just trying to picture this in my mind. When you get it on the muffs it starts and runs up just fine. But when you put it in the water it will start. Or it will not even start.<br />Or is it dying when you try to put into gear? If the latter is the case have you tried to just push it to WOT to see (please make sure this would be a safe you should know before you get anyway near WOT if she will keep running.)<br />I'm having a problem with a 150 that works fine on shore but the idle is low and ever time it is put into gear she stalls but if we catch it before it stalls she runs up. With this one I needed to adjust the idle and the cables since it wasn't getting to full. But the increase in idle stopped the stalling. Have you made any changes like a new prop or something? I'm assuming that when in the muffs you have put into gear and saw the prop shaft spinning so we know it is not the gear case that is the problem.<br /><br />I forgot to add that the ratio for the 150 I'm working on is 50/1 as well. This brings up an interesting question though. a while back (long while) I had an XS650 and when all the others were running 50/1 this one required 36/1 <br /><br />Alex

 

[clanton]

Re: charging / lacks power in water 150 merc

Check the stator output to switchboxes at cranking rpms, at idle, and at 1500 rpms, You need manual for wire colors and specs. Also need year, carb, fuel injection, direct injection, serial number.

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

out of water runs great! in water when i go to wot it just bogs, any where after 1/4 throttle. i can idle and go anywhere. when i put it in gear forward or reverse it does't stall it just wont go when i try to put the hammer down

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

 

[wrenchtrnr72]

Re: charging / lacks power in water 150 merc

this motor is a 1980 150hp xr2 mag. w/carbs serial # is 5503559, please help me before i blow this thing UP!(just kidding!!)