87 MERCURY 150 XR2 Trigger problem?

[Fishnfeever]

I've got an 87 Mercury 150V6 XR2. My symptoms are 2 Cylinders (#'s1&6) getting spark but, when I pull the plug wires, those two cylinders don't seem to make a difference when Idling. It idles pretty shaky and seems like all pistons want to kick intermittently. Worse with load. Also hesitant/slow out of the hole. Have set timing & Carb floats and checked carbs according to Secol manual. Stator Ohms good I think, Switched coil packs with known good ones and no difference. Switched plug wires around, no diff. Switched leads on Switch boxes, no difference. Compression is 121 on all cylinders. I don't live above 2500 sea level so jets are ok i think. Got flywheel off for visual and Magnets look ok. Not very experienced but on my way and my father has made a living as mechanic so I can fix if I can narrow problem. Want to be sure of problem before buying whole new or any part of expensive Ignition system. Would I be wasting my money buying a trigger? Please advise....anybody!

 

[j_martin]

Re: 87 MERCURY 150 XR2 Trigger problem?

2 items come to mind. Reeds is one. The other is that #2 and #6 each has a related crankshaft end seal.

hope it helps
John

 

[Fishnfeever]

Re: 87 MERCURY 150 XR2 Trigger problem?

Thanks for the info and reply. I've actually recenlty had the Reed plate off because it was blowing fuel out the bottom Carbs. Fixed that issue. I'll check into the seals. Did you say #2 and#6 share the same seal?

Jim

 

[j_martin]

Re: 87 MERCURY 150 XR2 Trigger problem?

Thanks for the info and reply. I've actually recenlty had the Reed plate off because it was blowing fuel out the bottom Carbs. Fixed that issue. I'll check into the seals. Did you say #2 and#6 share the same seal?

Jim

No. # 1 is on the top end of the engine, # 6 is on the bottom. There is a set of crankshaft seals on each end.

Getting at the top one requires pulling the flywheel. Getting at the bottom one requires pulling the power head.

If the seals are both bad, the main bearings are also likely to be bad. You could probably hear/feel that.

Another thing to check first is the carb and reed plate gaskets.

Spray a light mist of water at the base of the carbs, and the edge of the reed plate when idling. Any air leak will cause a change when it sucks it in. (slowdown) If you're in the open, you could spray a little carb cleaner or starting fluid (very little) at a suspected leak. It might cause that cylinder to pick up noticibly. This test could be hazardous.

Also, are you sure your bleed lines are in good shape and installed corectly. Be sure you have the right diagram as horizontal and vertical reed engines are different. Also be sure the check valve in the reed plate feeding each line is working properly. (some use a little syringe to test them. I use a soda straw and am prepared to spit out some gas/oil if I screw up.) Bleed lines don't seem like much, but they can really cause trouble with Idle.

There really isn't much to these V6 merc engines. Everything has to be right, and then they really go.

In ref to the original title,
Stator would kill 1 bank or the other, maybe at certain speeds.
Switchbox- 1 bank, or 1 cylinder.
Coil - 1 cylinder
Trigger, 2 cylinders, 1-4, 2-5, or 3-6
Yer description matches none of these, unless you happen to be real unlucky and have 2 bad switchboxes. That could be ferreted out by swapping the switch boxes, which would move the faults to 2 and 5.


hope it helps
John

 

[Fishnfeever]

Re: 87 MERCURY 150 XR2 Trigger problem?

Guess I'll get to turnin some bolts then. I will double check the bleed lines and check gaskets like you mentioned first though. I think I will swap the switch boxes totally too ...just to make sure.

Thanks again!