Mercury inline 6 150hp rough idle

[sourbsted]

Re: Mercury inline 6 150hp rough idle

Would a bad stator have any affect on anything? It's never charged the battery while running. I cleaned up the wiring to the stator, cause the insulation was gone. I rewired the stator.
I tested the charging system it doesnt work, just drains the battery like it always has. At idle the timing now stays on ATDC 6 degrees. I think because the carbs aren't closed complety I can't drop the idle enough to achieve a good idle. Going to have to spend a full day on this old girl.

 

[CharlieB]

Re: Mercury inline 6 150hp rough idle

You need a DVA meter or a DVA adaptor to test stator output to the rectifier, also should remove the rectifier and test it with an Ohm meter to ensure it is good, either a bad stator or bad rectifier and it will not charge. You got to test both to be sure which is at fault, you cannot assume anything with electrical parts as they are NON-returnable.

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

I may have made a break through today or maybe not. I disconnected the fuel line connection to the I6 and found it completely full of old crusty fuel. Looks like the old fuel line I used before I recently replaced had dislodged heaps of crap into connection. It's no wonder the boat won't plane it can't enough fuel! When I first hit the water first time round weeks ago both 15hp mariner and I6 both showed the same problems so it makes sense as to why it happened. Both motors were starving for juice!

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

I tested it out again, same problem won't plane.I also tryed to pump the bulb while it was trying to excelerate. The boat ramp is very busy this of the year. This motor is becoming a headahe. Back to the drawing board. Link& sync again.
https://www.youtube.com/watch?v=Av0kSlkI0nY&feature=youtube_gdata_player

 

[mr 88]

Re: Mercury inline 6 150hp rough idle

Okay we have determined that your belt probably snapped because of the distributor bearings going bad.By grabbing the shaft and rotating it you will not be able to "feel" the bearings,you really have to put your finger in the bearing and rotate it. When you put the new belt on were you off a half tooth ? If so you may have installed it on the wrong side,there is a manual out there that gives you the wrong info.I would re visit that belt and the LinkNsync to make sure it is where it is supposed to be.IF you are giving it gas and it is dying MY next step would be to check the metal ring that goes around the distributor and make sure the gap is correct where it meets the advance mechanism.That metal piece can be adjusted two ways,one is to adjust the phillip head screw stop and if you run out of room there are two[ I think 1/4"] bolts that you loosen with a small ignition type wrench,then move/rotate the adjusting ring so you can adjust the pickup gap again.I would adjust it one way maybe a 1/4'' and see how it responds,if worse go the other way and if better keep adjusting that ring. That was the main problem with mine not accelerating along with the wrong belt info from the manual,which affected the idle circuit a lot more than the top end. It would hit about 1500 rpm and then die out unless you backed out of the throttle then hit it,sometimes it would sputter past that dead zone then run like a bat out of hell.Too much gas and no spark advance to coincide with the fuel delivery.Sure would like to see you get her back to her old self,don't throw the towel in or lose hope,I believe it just has to be re set up in the correct mode.

Hi all,
My very old 73 model blue band has a rough idle and misses on when i try to run it on fast idle. Its been out of the water now for over 2 years cause the timing belt snapped. I had it running again soon after with an old timing belt it ran ok, But since I fitted the new belt its been running rough. I also fitted a electric fuel pump that activates when i push the choke button. Saves me pumping the damn bulb all the time!
I'm having trouble trying to find someone to work on her cause of the motors age. I also should add it has 135psi across all cylinders cause it has been re-conditioned..

Mercury Inline Tower of Power 150hp - Holeshot test - YouTube

Just a short video on how it did go before..

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

It seems like its all aligned good. Correct me if it doesnt look right. The white dots you can see are what my old machanic left behind, 4 BTDC degrees and 22 degrees. The alignment on the top of the dizzy is perfect.

I adjusted the gap between the throttle pickup tabs because it didnt have a gap at all! I was going to set it at 0.015mm but decided to open it up to 0.040mm instead. I hit the water again today and its no different.. ggrr.. Theres gotta be something totally wrong with this old girl! If i was going to compare it with a car motor i would say it sounds like its majorly retarted, Like its not on TDC or something. I left marks on the flywheel before i inially removed it..

adjusted the metal ring that wraps around the dizzy that has two very small bolts, to get better gap between throttle pickup and advance tab. Had no gap at all when it was on idle..

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

I got a little camera happy today It sounds so good why not film it..

http://static.photobucket.com/playe...ucket.com/albums/nn186/greenmk2/VIDEO0030.mp4

I'm thinking it may have carburetor problems, idles good, starts good just doesn't want to get up on to a plane. so I'm thinking main jets possibly?
When I first bought this motor and I was on my first outing I had idle jet block up. It has all of the same Symtoms as I'm getting now. I recently cleaned them (idle jets), checked float level, maybe a blockage elsewhere? I wanna pull them down again. Thanks for all the advice! I've learnt heaps..

 

[Faztbullet]

Re: Mercury inline 6 150hp rough idle

Recheck your timing as the arrow on pulley should be aligned with the 3 dots on flywheel, the mark on cowling cover means nothing as thats for the older 1150 and 1350 motors. The "bump" on pulley being lined up at TDC is what leads me to recheck timing....

 

[mr 88]

Re: Mercury inline 6 150hp rough idle

The linkage that I am referring to is the adjusting bolt right above the linkage that move the distributor. That adjuster is at the very top and as I was wrong when I said phillip head,it is a 7/16 bolt. The gap looks about right,but that does not mean it is advancing at the correct time as the pickup plate it self may have to be moved a bit with the gap adjusted accordingly.Also concur with Fbullet, get the timing done before messing with the pickup plate.

 

[CharlieB]

Re: Mercury inline 6 150hp rough idle

Have the carb fuel inlet screens been cleaned or removed?

A fuel restriction here will severely limit power to only that amount of fuel that will flow thru.

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

The arrow on pulley points towards the dots on the flywheel, I don't how to get TDC any closer. I marked the flywheel first time I had to remove it, so it would line up in the middle where it bolts on. I found an old timing belt yesterday, maybe I should swap it over and see how it runs.

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

If the throttle cable is set too tight that will hold the carbs open aand the timing advanced.

Disconnect the throttle cable and see if the linkage will push back farther, let the carbs close and leave a small gap between the carb linkage and timing. If so then readjust throttle cable.

Have the carb fuel inlet screens been cleaned or removed?



A fuel restriction here will severely limit power to only that amount of fuel that will flow thru.

Yes I have cleaned them, they were a little dirty. I didn't clean the main jets. I assumed they were clean. (assumed, the mother of all f#$k ups)
Fastbullet is right, the timing seems out. I might need to get a"dial indicator" I spose.
When I'm in the water and I give it a good hit, it trys very hard to plane but every attempt after that it just dies straight away . If I fast idle it for a minute of so it trys hard to plane again.

 

[Maxz695]

Re: Mercury inline 6 150hp rough idle

Don,t want to scare or alarm you. If all else fails and has so far then you might have to consider the lower seals are leaking and your loosing enough pressure in the case to not get enough fuel oil to the cylinders to keep it running right at the higher RPMS and the demand for sufficient fuel to reach maximum running opperation. I was having issues in exccelleration and found both seals where totally shot. I have scince replaced the seals and the wear sleeve on the end of the crankshaft yesterday. Waiting on a new trigger and some locktite with primer to reseal the case. Just a thought

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

Don,t want to scare or alarm you. If all else fails and has so far then you might have to consider the lower seals are leaking and your loosing enough pressure in the case to not get enough fuel oil to the cylinders to keep it running right at the higher RPMS and the demand for sufficient fuel to reach maximum running opperation. I was having issues in exccelleration and found both seals where totally shot. I have scince replaced the seals and the wear sleeve on the end of the crankshaft yesterday. Waiting on a new trigger and some locktite with primer to reseal the case. Just a thought[/QUOTE

I found this on a another forum..scary : (

The term "black anchor" was given to them in the days when they had steel (as opposed to stainless) driveshafts. The evinrudes & Johnsons (and even the lowly Chrysler) all had stainless driveshafts. Other problems included sideplates corroding through and the bottom crankshaft seals rusting out in the powerhead. In both cases you ended up with a seized motor that was good for nothing more then using as a (you guessed it) "black anchor". They were still a great motor if they were serviced on a regular basis and the sideplates and bottom crank seals were done every 5 years or so.

 

[mr 88]

Re: Mercury inline 6 150hp rough idle

The way you explain your issue it indicates to me that your timing and the plate I am referring to should be where your problem is. The Tower was running fine until the belt broke,correct? So if that is the case fuel/seals etc should not be a issue,it all went downhill after you replaced the belt,not before.Mine would do the same thing and sometimes it would stumble through the dead zone and plane out,run like a champ once you drove through it,which would take a few stabs before it caught.Timing was off and pick up plate needed to be adjusted

Yes I have cleaned them, they were a little dirty. I didn't clean the main jets. I assumed they were clean. (assumed, the mother of all f#$k ups)
Fastbullet is right, the timing seems out. I might need to get a"dial indicator" I spose.
When I'm in the water and I give it a good hit, it trys very hard to plane but every attempt after that it just dies straight away . If I fast idle it for a minute of so it trys hard to plane again.

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

It was two years ago, I was on the water going flat out then motor cut out. I removed the motor put it under my house on a stand. I decided I would strip it down to clean out the rear water jacket cause she had poor water per hole. (blocked up) its not like its sat out in the weather. It's been reconditioned, so I would think the seals would have been replaced.
I don't mind pulling the motor off to inspect lower seals, a massive vacuum leak is possible.
I just want to get to the bottom of it, I'm going back to work in a week and doing distance education for uni. So I'm going to have no time soon. It's like common word amongst May neighbors, "how's the motor going Jason" LOL I know what they think "he has some patients with that motor" LOL

 

[Maxz695]

Re: Mercury inline 6 150hp rough idle

One easy thing you might want to try is run the engine in the dark. (Neighbors always love that) see if the cap is arching. As current builds up the spark becomes stronger and may be shorting out the firing a or some plugs.

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

One easy thing you might want to try is run the engine in the dark. (Neighbors always love that) see if the cap is arching. As current builds up the spark becomes stronger and may be shorting out the firing a or some plugs.

I had mercury 500 blueband that done that, around the coil.
I should also mention I had big problems in the past trying to get this motor to plane out. It would take a while for her to plane out. The mach done the best he could. We got it sorted but he said something doesn't seem right.
I one occasion the lower unit packed it in so I replaced it with another gearbox. It planed a lot better after that. I think the old box was off a V6 well that's what the mach who sold me the replacement gearbox told me..

 

[Maxz695]

Re: Mercury inline 6 150hp rough idle

According to your pictures of the flywheel alignment at TDC #1 cylinder, and you have the piston for #1 at TDC (using a pencil eraser to determin the highest point of the cylinder) Then you should be right on with the belt and the distributor alignmnet set to fire #1 piston at that point with the rotor pointing at #1 terminal on the cap. Stetting the timing should have taken care of any timing issues. There has to be another reason be it losing fuel pressure, fuel flow, or a spark issue.Although I think I read the plugs where fairly new. could one have been dropped. I wouldn,t say a plug is good just because it is fairly new. I have seen them go bad real fast in the past. Just a thought. The distributor acts in place of the trigger sending the current to the cylinders I,m not sure if you have points or a pick up coil. There may be a condenser in there that has gone bad as well. I would suspect these parts as well as a weak coil as a cause. Hope you find the culprit

 

[sourbsted]

Re: Mercury inline 6 150hp rough idle

Well I pulled dizzy off, removed the carbs. The amount of rubbish in carbs filters! One of needle & seats was blocked up. One of the main jets had gunk in it, don't know if it would effect its operation. Carbs are completely pulled down now. Anather can of carb cleaner to clean it all up again.

This lead end that goes into the coil is in a very sorry s tate, I don't know how it even passed any current. That explains my erratic idle I was getting.

I want to clean up all the electrical connections and then buy all new fuel lines. The fuel lines going to the carbs are badly cracked. Dizzy spins easily,bearings seem good. I have kits for the fuel pumps, hopefully the check valves are ok..