1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

[aerobat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I think you have a fuel supply issue from the boat to engine as a 115 would need less fuel than a 150. Try running it on a test tank with a 3/8 supply line.

i also guessed in this direction, but sparkie says he has tried an alternative fuel supply with no result. a picture of the plugs would help to chek if this thing is running lean or not.

beyond that ,would en engine which struggles to get enough fuel at WOT run - like sparkie claims- perfectly smooth but just with a low power output? i doubt . i would expect missings, bogging, roughness etc.

 

[j_k_bisson]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

Correct me if I am wrong, but I thought that after a certain throttle position, say 3/4 throttle, the timing is not being advanced any more. So it would be all fuel delivery from that point forward.

So with this thought there would not be any bogging or missing. The motor can only run as fast as fuel is flowing.

Sorry to chime in, but I have the same feelings about my 1987 225hp Evinrude. My buddies Merc 200hp out runs me everyday. Don't know why.... With all the extra weight with this hanging on the back of the boat, I don't see the reason why anyone would want to have one..... Less power and more weight (an aditional 100 lbs) = no good. If you read all the info from their advertising from back in the day, they where supposed to be making more power than all others. I just don't see it. It's quite less.

So Sparkie when you figure it out, I would love to know what the issue is.

Also have you changed out your fuel separator and in-line fuel filters? If they dry out they do cause restrictions due to varnishing...... Seen it on other types of motors that get no maintence....,.

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I have used a test tank with a 3/8 line, it made no difference. this thing really has me at a loss, usually when an engine is starving for fuel it will surge some, this thing is straight up smooth with no surging at all. but I have considered using a test tank and bypassing the entire fuel pump assembly, I have a small low pressure electric fuel pump I could put inline and rig up a temporary fuel supply with it. go straight to the carb rails. it will be thursday or friday before I can do another test run.

and yes full timing advance is reached around 5/8- 3/4 throttle.

thanks for all replies, you guys are really keeping me thinking on this thing.

 

[aerobat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

you really should pull a plug after a high speed run to check if it runs excessive rich or lean.

you really checked that all throttle bodies open fully?

one last idea are bad bearings with a high resistance in the lower unit so many horses are lost there.

never had this series engine, but maybe its just a sitting dog tending to be on the weak side of 150 horses?

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I will do a high speed shut down and post pics of plugs thursday or friday. here are some pics of linkage and throttlebody.

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

 

[aerobat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

the picture may give a false imagination but it seems that the throttle valve of the medium carb is neither fully open nor synchronized to the lower carb throttle valve ( where you removed the silencer intake and float chamber) . check this carefully on all carbs

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I am not sure what you are trying to say, but all of the throttle body butterflies open fully and are in sync with each other. maybe the pic is deceptive.

 

[Haffiman]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I'm more interested in your timing setting, Both low and high seems to be set at the lowest possible. On this engine idle sped is set by adjusting the 'low' timing setting, but may someone accidentally have lowered the 'High' setting when adjusting idle"?
Normally the ask for the 'ignition analyzer' to set the timing, but is may as well be done using a timing light and cranking just do not point the light at the optical sensor directly. Suggest you do a double check on the 'High' timing setting.

 

[aerobat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I am not sure what you are trying to say, but all of the throttle body butterflies open fully and are in sync with each other. maybe the pic is deceptive.

yes, i was talking the throttle butterflies . when you verify that all six open fully and are synced properly than ok. on the picture the medium butterfly looks somehow not fully open.

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I have double checked the WOT timing, it is on 20 DBTC on the money. I double checked it while running down the river. idle timing is 4 ATDC.
I used a timing light.

I also was wondering why the timing markers are all the way down with both. I wish I could turn the idle down a couple of more degrees, because the idle is about 100-200 RPMs too high. on the muffs it idles at about 1200 RPM in the water it is 900-1000ish. Anyone know why my timing may be like this?

 

[j_k_bisson]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

Seeing I have not seen your throttle linkages, but on my 200 there is a scew on the side that is also a idle set screw. By chance is this screw engaged? When I did my linc and sync, it calls out in the manual to back this screw out all the way. Set everything, including timing, then take up the play in the screw.

Just a thought from a hung over guy..... Hope it helps...

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

I hope your head ache goes away soon. you need to try the vodka that has been distilled 5 times, really lowers hang over effects, really clean alchohol.

I will check but I do not think I have such a screw. these 60 degree motors have carbs connected to throttle bodies, there is a idle air screw for each carb, I could probably adjust those to reduce idle RPMs, but I still wonder why my timing markers are both bottomed out.
and can anything be done to adjust this?

 

[Haffiman]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

Idle speed on theese engines are adjusted by moving the 'Low" idle timing tab towards '-'. No screws to 'screw up'!!
Have you verified the pointer at TDC??

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

yes TDC on the timing pointer has been properly set. I cannot move the low idle adjustment any further. it is very likely that the flywheel cover and timing arm are from different year motors, it appears that my motor is a mix match of parts.

It looks like I could grind about 1/8 inch off the timing arm where it hits the stop would allow it to go back another couple of degrees.

 

[j_k_bisson]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

But that would move your top and idle timing. You would just move the range by doing that. Right?

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.



it should not effect WOT timing at all..only idle

 

[j_k_bisson]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

But if you move the timing mark then both the Wot and Ilde timing moves right?

This would not fix your top end issue. Only your idle issue.

Now just to recap even if you modify the timing mark. You stated that you orientated the time mark to indicate TDC. So in sense you will not be affecting anything if you go back after you modification and reset TDC.

If you have confirmed you Spark is good, and your compression is good, then it is only fuel. Any chance you have a air leak that only shows up at high idle? It could be the result of a fuel restriction causing a vaccum to be generated and air to be sucked into the motor. It could be anything from a recirc line that is cracked and causing a vaccum loss in the intake/reeds plates, or the primer solinoid hose that is a bit loose and causing a back feed air leak to the rest of the fuel system.

Also could it be the primer solinoid is partially open and cause a too rich condition that is loading the motor with fuel at High RPM's?

How about a crack case air leak? You said you split the motor. By chance something is not sealed?

I have the same issue with my motor. So when you figure it out I will be going thru mine. It runs but not at what I expect it should.

 

[SparkieBoat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

what I am talking about doing to the timing arm will not effect WOT, take a look at the pic above, the arrow is pointing to the spot where I will grind 1/8 " . this will only allow timing arm to go back slightly further thus retarding idle timing slightly.
I have considered a air leak, recirc lines all appeared ok, it is possible there is a leak somewhere else, but danged if I know where to look. I saw no cracks anywhere and I looked pretty good. I do not think the solenoid is leaking but I will check it out.
an air leak is my best guess, but I just cannot find it, if it is there.

 

[aerobat]

Re: 1994 60 degree 150 HP, only getting about 100-110 HP. cannot find the problem.

it is very likely that the flywheel cover and timing arm are from different year motors, it appears that my motor is a mix match of parts.

sparkie, in this case maybe you just have to accept to live with what you have. when the engine is a mix there are many many variables what it could be. maybe a mix of not optimum timing, not optimum compression, not optimum carbs - so some horses get lost without any chance to do anything about it .

the timing arm alone , from a different motor, can be the reason for weak power.

can you get your 115 back ?