The World Famous Bull Sessions

Vintage Sleds, Vintage snowmobiles => Vintage Tech Help => Topic started by: struggler on March 20, 2020, 02:21:17 pm

Title: No Rev 1969 Merc 220E
Post by: struggler on March 20, 2020, 02:21:17 pm
Circling back on this project.  I restored this machine, including the wiring harness.  It starts, lights work, but when you give it gas, it doesn't rev up enough to engage the clutch. It doesn't bog down. It can idle all day.

1) PSI > 120 in both cylinders on one pull
2) Good spark: new plugs
3) replaced fuel pump
4) replaced the old fuel lines
5) cleaned carb several times and tried another carb

Back to timing?  The pictures show that "thinger" next to the flywheel. I've adjusted this up and down and no change in RPM.  This doesn't have the points system, it's an old marine engine I guess.

Not sure what the next step is.  I like looking at this machine, but It would be nice to ride it someday.

Any input appreciated.

Mike
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 20, 2020, 03:38:06 pm
What happens if you use a spray bottle and spray a mist of fuel in the carb while you are squeezing the throttle? Does it fall on it's face?
I have two 250's and I'll try and walk through this with you.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 20, 2020, 04:53:17 pm
Excellent question.  It does nothing. Just keeps on running at a fairly constant rate. I shot some starter fluid in the carb last time it was running (with throttle open).

Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 20, 2020, 07:55:14 pm
Are you sucking any air into the crankcase? Maybe through the primer ports on top of the cylinders. A lean situation will make them run like that. Cracked or broken primer hose?
Are both plugs firing under load? I know you said new plugs but are they actually firing?
Is it starving for fuel? The line that comes from the sediment bowl over the carb to the fuel pump will look good but the way they routed it from the factory will sometimes squeeze itself to limit fuel flow.

I'm like you, I like looking at them also but they are also fun to drive.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 20, 2020, 08:59:05 pm
Thank you for helping. 
1) I'll check the crankcase.  I think I've sprayed starter fluid around it before without flame. However, the primer ports! I just replaced primer line on my 250 (didn't fix that problem, but that's for another day). I better look, because I don't have a primer on it right now.

2) Hoses all replace, but again, no primer right now.

3) Good spark on both sides

4) I've replaced line from the tank, the fuel filter and there seems to be plenty of gas, as it leaked all over when I pulled off the fuel pump.

Side note.  My 250 I bought in 2007 and it was running. Ran great until a ride in Withrow MN this past New Years Day. Great, loud, fun sled.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 20, 2020, 09:22:27 pm
Shoot.  I was optimistic!  The primer ports have, what would you call them, stopper bolts?  I don't believe there was a primer on there. This did prompt me to go to a spare engine and take the primer line fittings off to be used later on this machine.  I noticed on the old engine that there are rubber lines on the bottom of the engine.  I wonder if it's sucking air down there?  There is some dark oil-gas mix that collects below the engine.  Hate to think I might need to pull the engine off, but maybe.

Title: Re: No Rev 1969 Merc 220E
Post by: Mr_Plow on March 20, 2020, 11:27:43 pm
Could the exhaust be plugged?
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 21, 2020, 12:49:41 pm
That's a good questions. The exhaust comes out of the pipe and feels strong.  That doesn't mean there isn't a partial blockage somewhere.  I might be able to disconnect the exhaust under the seat and get a look. the tail pipe angles down.

thanks

Mike
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 21, 2020, 02:41:19 pm
I can tell you why the oil mess collects below the engine. When these machines were produced, Mercury found it necessary to make the exhaust manifolds rigid all the way back to the muffler connection, clamp it solid then add another 30+ inches of muffler then add another 6+ inches of tailpipe then turn it down. All the while clamping all this madness tight to the chassis. Chassis is aluminum (thank god) but it tends to flex. The weakest point on this system are the 1/4 bolts coming directly out of the cylinder fastening the manifolds to the cylinders. When the sled flexes (while riding it) those bolts snap, you then get a loud manifold leak=messy oily goo under the engine. If you intend on taking your engine out of the sled, I have figured out a remedy and a true fix for this and it's NOT the half assed flex pipe repair that Mercury came up with back in the day. More than likely you already have the flex pipe and they are leaking gooy nastiness already.
Are you sure you don't have a fouled plug? I remember this happening to my dads 250 when it was new. It would run but would not rev up. I was a snot nosed little kid then so I don't know what the findings were.
I can go on and on about these things. I just love them!!!
There might be plenty of fuel with the engine not running but running might be a different story which I asked if it was starving while it is running.
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 21, 2020, 02:46:51 pm
Have you taken the recoil assembly off to clean out the mouse nest? They love it in there. That's one of the reasons these engines fail, mice get in there and build a nest. Clogs the cylinder fins and overheats and burns them down.
If you do take the muffler off check the little outlet on the inside, the mice like it there also.
Title: Re: No Rev 1969 Merc 220E
Post by: weverat on March 22, 2020, 12:14:06 pm




Back to timing?  The pictures show that "thinger" next to the flywheel. I've adjusted this up and down and no change in RPM.  This doesn't have the points system, it's an old marine engine I guess.



Mike

Sounds like you have some type of electronic ignition. I would verify that those parts are working. Do you have another engine with the same parts that runs?
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 22, 2020, 01:47:10 pm
skidootntfa,

Very interesting. I took a look at the older "parts" motor and sure enough, solid connectors where exhaust comes off the engine.  That makes perfect sense.  I'm fairly certain it's not the plugs. I've replaced them multiple times.  I'll try pulling gas from a separate tank directly to fuel pump and see if there is any difference.  And the nests!  Yes, I've dealt with that on my 250. Was riding a few years ago and couldn't believe the smell of burning nest, urine, whatever.  It ran hot that day and I'm lucky it survived.  This year i didn't do a good job of checking and sure enough, a nest.  Now that one is out of commission too.  Good stuff. 

weverat,

The electronic stuff is my weakness. Lucky to have an electrical engineer that works on these with me. we replaced the green switch box, wiring harness and everything works form spark to lights. It has a CDI system which is "powered by a flywheel mounted generating coil and a trigger could attached to the housing." I'm probably wrong, but with how easy it starts and smooth it runs, seems timing isn't horribly off. Even if off a bit, wouldn't the thing still rev up more when throttle opened?
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 22, 2020, 02:57:38 pm
Does the sled move under it's own power? You have said how it runs but does it move?
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 22, 2020, 03:07:28 pm
Did you check the reed cage?
Your ignition seems to be working great. You went through all the components.
You went through the carb and necessary parts.
Seems like the exhaust is working like it should.
Fuel doesn't seem to be getting to the cylinders like it should to give you an increase in rev's. The only thing between the carb and cylinders is the reed cage.
Yes everybody this sled has reed cage induction just like it has CDI way before anyone else had it. OMC also had their version of CDI. Mercury's engine even ran backward when you put it in reverse. The new ski-doo's have nothing on Mercury when it comes to going back ward.  8)
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 22, 2020, 05:10:27 pm
Reed cage?  now what is that? LOL.  i think it is the finned looking thing behind the carb.  The sled does not move.  It does not rev up. No change with any throttle action. Yes, the throttle cable is connect tight and the valve opens and closes in the carb.  So the clutch does not engage and there is no track movement.

Thanks. 
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 22, 2020, 06:14:57 pm
Found the reed cage on the spare engine. 10 small, round valves. Looks like the valves are built into the engine. Best case? oxidized/ dirt? nest? Worst case? Broken valves?  The latter might require a different engine?

This is great, the best part of the hobby.  Not really frustrating, as educational.  I have too much time on my hands for awhile. Was supposed to be on a beach, this week, not full of grease.

Mike
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 22, 2020, 07:28:13 pm
Those reeds are actually little spring valves. As you accelerate they open on the intake and spring pressure causes them to close on the compression stroke so you get minimal spitback so the engine uses the whole intake charge. All motors are reed valve motors. Either mounted in the cylinders or in the case, they serve the same purpose. The reed cage is removable on these engines. They are mounted with 6 allen head flush mounted bolts. Take the carb and intake assembly off and you'll see the whole reed cage. If I remember 1 reed assembly per cylinder. An inspection won't hurt especially if you've never seen these before. None of them should be stuck open. They should all spring shut and seal.

Good luck  ;)
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 22, 2020, 07:31:20 pm
I mentioned all motors were reed valved. I meant these Merc 220 and 250's. Most of the new engines in the new sleds are reed cage motors. There are piston port and rotary valve motors but that's a different topic on a different day. Today is Mercury reed cage motor day.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on March 23, 2020, 02:26:05 pm
I take a look at the reed cage and valves on my 220 today or tomorrow.  Can we still order carb kits and other gaskets from Mercury? Otherwise, I'll be cutting my own new gaskets.  Awhile back I was looking for some sort of, at least gasket, kit for the MD147A carb.
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on March 24, 2020, 11:53:46 pm
I don't think so on the gasket kit from Mercury. But you never know, they ran snowmobile engine parts in their outboards and vice versa... :-\
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on April 01, 2020, 07:31:14 pm
Any updates on the Mercury??
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on April 02, 2020, 12:59:50 am
Not yet.  I did not get around to taking the carb off and examining the reed cage.  I did, however, take apart the older engine to learn what the reed cage is and what the 20 valves look like.  I think the next step is to pull the carb and take a look. Not sure how bad it would have to be to prevent revving. If the reed valves look good, then I go through all of the exercises again. I'm wondering if one of those really small holes in the carb is blocked. I bought some fine wire tools for trying to clean them out.  Anyway, hope to find some time this weekend. Thanks for asking.
Title: Re: No Rev 1969 Merc 220E
Post by: Earl on April 02, 2020, 01:20:09 am
I bought a micro-size drill bit set from a hardware store.  The bits are so small they will clean out the tiniest holes in any carb. quickly.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on June 25, 2020, 09:40:31 pm
Okay, three more running and now back to my nemesis. It's been awhile since I've post on this.  1969 Mercury 220E with Kiekhaefer engine and MD147A Tillotson carb.  Today, I finally inspected the reed cage. All valves looked great. So...

1) 120 PSI both cylinders
2) spark plugs good and spark on both sides
3) fuel line clean, intact, without kinks (I'll admit, I found the filter on backwards. This didn't fix the problem)
4) carb gone through multiple times, but most thoroughly the other day. Found residue on needle and an inlet.  This did not fix the problem.
5) Kind of looked at timing at one point, but his has a form of CDI. Pretty simple and the machine idles smoothly. No back fire, etc.
6) Exhaust does not appear blocked
7) checked primer ports - both tightly capped/ sealed, not in use.
8) Today while it was running, I sprayed starter fluid in the carb.  No change in RPM.

????

So, I've been assuming a fuel delivery issue.  However, it's all about air:fuel ratio and I think it's around 15:1.  Is it possible that too much air is getting in?  If too much air, kind of the same as not enough gas. Bad seals, cracked crank case, shot rings?  The thing is, it starts easy, idles nice, and when you open up the throttle it does nothing. It does not bog down and die.

My current thought:  When I had the read cage off, got down close with a flashlight and turned the clutch, I could hear air leaking.  Could it be a bad ring all along? Sounds like the MAG side.

Slow as it goes.

Mike
Title: Re: No Rev 1969 Merc 220E
Post by: skiroulekid on June 26, 2020, 03:22:40 am
Years ago I had a Harley sled that did the same thing, I was told it was something in the electrical system that would not let it rev up.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on June 26, 2020, 03:44:35 pm
Interesting.  I'm trying to figure out how this electrical system would come into play.  If there is enough current/ voltage to create enough heat to spark (and it looks like a good spark) and the timing is on, I don't know what else there could be.
Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on June 26, 2020, 09:04:11 pm
I have seen weak spark cause that problem.Test the spark with a spark tester or screw driver,how big of a gap will it jump?
Title: Re: No Rev 1969 Merc 220E
Post by: SnoDeere on June 29, 2020, 06:52:01 am
Does this motor have a 2 stage stator? The first stage looks after the starting and idle and the second stage takes over after that. The second stage could be defective and maybe that's why its not reving up.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on June 30, 2020, 03:19:24 pm
It has surface gap plugs.  Does a typical in-line spark tester tell you the strength of the spark or do they just glow if there's any spark at all?

Someone mentioned the stator a long time ago. It might be in a 2018 thread on this machine. I didn't really look into it much, as I didn't understand it.  I just recently learned how to replace points and do the timing on another machine. This machine is a bit different. To answer the question, yes I think it has a 2 stage stator.  I say this because it has two levers, one for the choke and the other for ignition, going to what's called a trigger coil.  There's an adjusting plate for advancing and retarding, clearance adjusting screws and timing adjusting screws.

Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on June 30, 2020, 07:37:48 pm
You can test with a spark tester that has an adjustable gap or put a screwdriver in the plug wire and hold it away from an engine ground,the amount of gap it can jump shows how many kv your system is capable of producing.
Title: Re: No Rev 1969 Merc 220E
Post by: skidootntfa on July 06, 2020, 06:00:43 pm
For some reason I still believe it's fuel related. The more the fuel that is fed the motor should accept and all the ignition components should follow (meaning it should rev up as the fuel is being fed to it). You have spark because it starts, you have proper timing because it's not popping out the exhaust or through the carb. WTH?
Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on July 06, 2020, 09:20:27 pm
Is the throttle shaft broke off? I have seen weak spark idle and then bog out when throttle is opened but he says it does not bog out just idles.
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 07, 2020, 02:20:36 am
Amazing.

I won't list everything that I've gone through again, but the last list was not complete!  I've also replaced the fuel pump and various other lines.

I'm stumped, but sure have learned a lot and I'm pretty quick taking off and putting on that carb, not to mention everything else. Maybe subconsciously I don't want it to run, it's become an illness?  ;D  I was excited when I found a similar post online and then realized it was mine from 2018.

I've visualized the throttle valve fully open and close. I cannot explain why it doesn't bog down, but it doesn't.  I've sprayed starter fluid in while running with the throttle open. No change.  I did remove the trigger coil assembly on a spare engine. It had all sorts of crud over the surface that faces the flywheel. Not sure what that would do, but it might be worth removing the trigger coil on this machine and cleaning it.  Maybe switch em up?

IDK.  Engine starts fairly easy. Idles smooth.  Exhaust porting out the exhaust pipe.  Spark. Compression.  Will this run before we have a vaccine?

What would happen if the float wasn't working?


Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on July 08, 2020, 01:13:21 pm
Has it been run without the muffler?
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 08, 2020, 04:56:29 pm
It has not been run w/o muffler.  My buddy is coming over tomorrow night. We're going to see if we can clean the trigger coil, check the gap and play with the timing. 
Title: Re: No Rev 1969 Merc 220E
Post by: Earl on July 08, 2020, 06:19:08 pm
Has it been run without the muffler?
  my thought also.......
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 10, 2020, 01:56:11 am
Took muffler off.  Probed and looked into the pipes.  No nest or obstructions.  Started the engine.  Very loud. ;D  Same deal. Started right up, no rev, no bog. Then I noted that the black fuel that accumulates below the pipes was coming out of the mag side exhaust port. We formerly thought it was from the pipes breaking near engine due to an aluminum chassis with flex and non flexible steel pipes.  This might still be the case.  Checked spark, but not with tester.  Both looked great and audible.

At this point i unplugged the mag side plug, pulled the starter. Started right up.  Same deal. So apparently we're running on one cylinder or 1 + minimal cylinders.  Now what are the thoughts?  I think bad rings, despite PSI about the same. Have not done a leak-down test, as I don't yet know what that is.  I think the next step is pulling the engine. However, probably should get a spark tester to make sure that's not the problem.  Obviously it is not burning all of he fuel on that side.

Still learning.
Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on July 10, 2020, 03:29:06 pm
Spark test,it should jump a 1/4 inch or more
Title: Re: No Rev 1969 Merc 220E
Post by: 73 RATX on July 10, 2020, 06:53:59 pm
Does the mag side piston have a skirt on it?
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 11, 2020, 05:12:16 pm

Great advice. This might be a bad plug wire or coil issue. Must rule this out before pulling the engine.

Spark test.  I think someone explained this to me already, but without buying a spark tester that just says "spark," or a $70 tester that has an adjustable gap, what's the easy method?  It's a surface gap plug.

Also, what is meant by a "skirt" on the mag side? 

Thanks.
Title: Re: No Rev 1969 Merc 220E
Post by: Earl on July 11, 2020, 05:22:57 pm
what happened when you pulled the clutch side coil wire?  Mag. side plugged in....Are the plug wires on correctly and not reversed?  Ie: coil wire 1 going to #1 plug, coil #2 to plug 2.     Piston skirt: pull exhaust manifold off slowly turn motor over looking for a piece of piston broken off.  By pulling off the intake you do the same, opposite side of the piston.  Google piston skirt many pictures of what 73 RATX is talking about....
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 11, 2020, 10:06:06 pm
Alright. We're getting there.  I can't see the skirt (sorry, didn't know that each part of a piston has a name. of course it does, like a spark plug and everything else).  If you're familiar with these machines, the piston is a long ways in there - long exhaust, even with muffler removed.  PSI 35.  No clanking. 

I switched up the coils.  They both attach to what they call a "switch box."  I took the wires from the PTO side coil, the side that runs, and attached them to where the mag side coil attaches.  I left wire off of PTO side.  So now testing the mag side that did not run.  Whammy. Started right up. REVS UP!  Clutch engages and the belts goes.  This is all on the mag side cylinder.  So better running on this single cylinder.

What does this mean?  Bad coil I'm assuming?  I guess to answer that, I need to hook the mag coil up to the PTO side and see what happens.  Anyone confused yet?

This thread is getting long. Hope I'm not out staying my welcome, but this is really interesting.

Mike
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 11, 2020, 10:18:44 pm
I'll reply to myself as I just realized, I think, that this comes down to the spark plug wire or the coil.  The next logical step is to now try the other plug wire and see if it runs the same.  If it does, then I'm posting for one of these odd red coils in the classified section.

 :)
Title: Re: No Rev 1969 Merc 220E
Post by: struggler on July 11, 2020, 10:53:21 pm
Both wires work. Both coils work.  With coils reversed and plug wires crossed, runs like a champ.  I'll switch things back. Many hours later the Final diagnosis = loose connection at the switch box and not obvious.  Hmmmm.  Well, should be good for awhile with a rebuilt wiring harness, multiple carb cleanings, new fuel pump, new gas lines, reed valve inspection, muffler checked, new plugs, new fuel filter, fresh gas, good compression and I will tighten up the muffler and exhaust components better than where they were.

Thanks all! 

Thread retired.
Title: Re: No Rev 1969 Merc 220E
Post by: Earl on July 11, 2020, 11:19:32 pm
that is good news, congrats.... I would have lit that thing on fire a long time ago. ;D
Title: Re: No Rev 1969 Merc 220E
Post by: 399jlo on July 12, 2020, 12:47:35 am
Congrats, think snow
Title: Re: No Rev 1969 Merc 220E
Post by: twinrotor on July 12, 2020, 01:21:15 am
See that wasn't so tough,but invest in a 5 dollar spark tester and be sure any engine can jump at least a 1/4 inch gap.Testing spark with the spark plugs is not a viable spark test.