Timing Problem? ( with video)

[Olias]

Okay folks, I am beside myself. I have tried everything I can think of (and have been suggested to do/try) and still can't get this motor to run properly. I have new coils, new points & condensers, new fuel pump, new spark plugs, have done a rebuild on the carb and I still can't get this motor (see signature) to idle properly. I'm brand new to O.B. motors but my problem "seems" to be a timing issue, possibly. I say this because I can get the motor to start (when It's cold) but the only way I can get it started and idle is at a pretty high rev/rpm. The thing is that at low RPMs the armature/ignition plate vibrates back and forth pretty violently. But if I give it gas (in neutral or in gear) the armature/ignition plate is rock solid. No vibration at all. Nice and smooth. So it makes me think that the timing is off a bit. I have the points set (at .20) to open at the middle of where its says "top" on the cam. Do I need to adjust them so the points are at .20 at the beginning of of where it says "top" maybe? I just can't get this darn thing dialed in. Any suggestions? Thanks.

-B-

 

[nwcove]

Re: Timing Problem?

Re: Timing Problem?

if your mag plate is wobbling it will throw the timing off by many degrees . there is a "joe reeves" method to correct tho. its as simple as removing the mag plate and GENTLY tapping the brass ring at the 12, 3 , 6 and 9 oclock positions with a punch and hammer. i do mean gently! first time i tried it ( same issue as yours), i went a bit to hard and had to undo some of what i did. you may have to take it apart a couple of times and repeat until you get it right. ie....throttle not to tight . jmo

 

[Joe Reeves]

Re: Timing Problem?

Re: Timing Problem?

(Magneto Armature Plate)
(J. Reeves)

If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.

The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make a slight indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.

You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

Use a small amount of anti corrosive grease between the aluminum ring and the brass support plate and also on the brass bushing of the armature plate when all is well.

----------------------
(Magneto & Driver Coil Alignment)
(J. Reeves)

To align the coils properly, have the metal vertical portion of the coil yokes aligned with the inside edge of the bevel that exists on the top portion of the aluminum seat upon which the coils sit. This creates the proper distance between the coils and the flywheel magnets. Faulty alignment creates friction and the yokes of the coils heat up, turn blue and expand.

---------------------------
(Point Setting Of Magneto Models)
(J. Reeves)

Set the points as follows. Have the flywheel key aligned with the fiber rubbing portion of the ignition points. Adjust the gap so that a .020 gauge will pass thru but a .022 will not. Should there be any question of the points being dirty (touching the contact with your finger would cause them to be dirty), clean them with a small brush and acetone or lacquer thinner.

NOTE 1: Should the operating cam have a small portion on it with the word "SET" imprinted, align this portion with the fiber rubbing portion instead of the flywheel key.

NOTE 2: Should the cam have the word TOP imbossed on the top of it, that is a cam that could be installed upside down and this is simply telling you which side is up. It is not a position where one would set the points.

 

[Olias]

Re: Timing Problem?

Re: Timing Problem?

Thank you for your in depth reply. I understand pretty much most of it but would like to very a couple things. I'm curious in particular about what you said about the cam, "NOTE 2: Should the cam have the word TOP embossed on the top of it, that is a cam that could be installed upside down and this is simply telling you which side is up. It is not a position where one would set the points." because that is exactly what mine looks like. There's a small recessed rectangle area that says "TOP" and is where I've been setting my points at. By eye it does look like the highest point on the cam but now I'm wondering if it is or not. To ensure that I'm at the TDC would it be correct to remove my spark plug(s) and turn the cam shaft via the prop and watch for the top #1 piston to reach it's farthest travel (in this case towards the spark plug) and then look at the cam and mark that spot for setting my points IF it isn't in the area marked TOP?

Secondly....as far as the "support plate" is concerned. There are 4 screw holes and a rectangular key way. What is the key way for? Does it need to be lined up with something? It seems unnecessary because (at least on my motor) you have to have the cam off to get to it which means that the only key (on the crank shaft) is already removed. Kind of confusing. Also, with the position of the 4 screw holes it appears the plate can only be in one of two positions in order for the screws to line up with the bolts coming down through the coil base. Is one way correct over the other? Basically the key way would either be on one side or the other because the screw holes are basically in the same position when spun around, just moved 180 degrees. Follow?

Lastly I just wanted to clarify what I said/meant by saying that the armature plate is vibrating. I may not have described that properly. It's not that it's wobbling. I've seen a video or two of people describing that and it's not that at all. It's more of the whole unit, flywheel, magneto plate etc., are shuddering at low rpms. When I look at the little mark that lines up with the cam roller at low rpms that mark is moving back and for in front of and behind the cam roller and the motor runs really rough like the timing is off and is next to impossible to keep running without revving it up. But as soon as I do rev it up everything smooths out very nicely and holds steady. Does that make sense? I'm really starting to think that (hopefully) I have the points set to open at the wrong spot on the cam. That might explain why it will start, run rough, but as I give it gas and in essence advance the spark/timing why it smooths out. Is that a correct assessment?

I'm at work right now so I can't check this out right now but I can't wait to get home and (oh boy...get to tear it all apart once again ) and check some of this out. Sorry for the long post. Any thoughts on what I've said here? Thanks.

-B-

 

[Joe Reeves]

Re: Timing Problem?

Re: Timing Problem?

Setting the points..... Your method has the engine running slightly out of time. Set the points as I instructed and ignore the imprinted "TOP" marking of the cam. Also, align those coils properly.

The Support Plate "rectangular slot"? If you're speaking of the one in the threaded aluminum ring, that's simply a factory thing... keeps the ring securely located when being machined. Ignore it.

The wobble/vibrating mention... hopefully you aren't saying that the flywheel actually tilts and vibrates. However, for now, get the points set properly and adjust the carburetor as follows.

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[Olias]

Re: Timing Problem?

Re: Timing Problem?

Thanks again for your response. Rats, sounds like I do have the points set at the correct area because the the area that is marked "Top" is dead center in front of the key. :blue: That is to say that I assume by "with the fiber rubbing portion of the ignition points" is referring to the little nob on the back side of the points that makes contact with the cam. Yes? I will Dbl check once again just to make sure but I think I'm right on as far as that goes. Got to admit I'm confused about the suggestion given by nwcove about marking and tapping with a punch on the armature plate. Although there are several holes in each position (4) it looks like to me that there is only set of holes I can put the 4 screws into that will align the plate so that the ignition mark (or what ever it's called) will line up with the cam roller when the throttle is in the start position. Like I say, I'll take another close look when I get home today.

BTW....below is a stock photo of my support ring. It's kind of hard to see but the keyway that I'm referring is on the right where the red line is.

-B-

 

[Olias]

Re: Timing Problem?

Re: Timing Problem?

Aha!! I stand corrected! Thanks to your info. and suggestion on setting the points Joe it got me to thinking. Is that "Top" mark actually dirctly in front of the Key or off to the side a bit. I haven't been home yet but found a pic of my cam and as you can see indicated by the red line that this is where I have my points set to open and indeed it is off to the side of the key. So it sounds like I should be setting the points to open where the blue line is which would is directly in front of the key. Would that 1/4" or so make a huge difference as far as timing and running rough? I'm hoping so. Now I really can't wait to get home and reset my points! :joyous: I will start with that 1st before dinking with the coils etc., as I believe my coils are spot on as far as alignment and how I understand they should look/line up. I'll report back!

-B-

 

[Olias]

Re: Timing Problem?

Re: Timing Problem?

Well dang it anyway. Got home and checked my points. Sure enough they were set to open where it says "TOP" on the cam instead of at the key. So I reset them, regapped for good measure and put everything back together. Tried to fire her up and it took about 8 pulls instead of the usual 2 or 3. Got er' started and dialed in the low speed needle. Although it seems to be running a bit smoother at lower rpms it's still (IMO) really shuddering and wants to die all the time unless I rev it up a little. I have to admit it's running longer now before dying out but when it does die it takes a ton (6-10) of pulls to get it going again and only if I go past the start position to fast on the throttle handle. When it starts it's naturally revved pretty high so I have to immediately slow it down a bit. I'm just stumped.....:blue:

Anyway, I thought it might help if you could actually see and hear it so I attempted to take a small video while I had it running. I just grabbed my sons GoPro that was laying near by and did my best so don't expect a great video. The main thing(s) to pay attention to are the flywheel/armature plate vibration at both low and high rpms. Heck, the shuddering I'm describing may be more normal than I think but I don't have anything to compare it to. I also tried to show the exhaust and pee holes to see if you think that all looks normal. As soon as the video is done being converted on Vimeo I'll post a link to it for ya. Thanks

-B-

 

[nwcove]

Re: Timing Problem? ( with video)

if all is well with your motor, it should idle very smooth. did you try adjusting the ls needle? from my experience, the standard 1.5 turns out is just a starting point....you may need to go as far in as 3/4 or out to 2 turns before it runs well .

 

[HighTrim]

Re: Timing Problem? ( with video)

Just for your reference this is how to punch the brass ring.



What type of compression does the motor have?

After setting points, did you TEST the spark? The spark should jump a 1/4" gap on an adjustable tester with a bright blue ZAP!!'

You say you set the point gap to 0.2, I hope you mean 0.020, lol

After setting, did you clean them with acetone or laquer thinner?

 

[Olias]

Re: Timing Problem? ( with video)

nwcove.....yes, I dialed the LS needle in. Tried different adjustments while it was running and found what I thought was the sweetest spot and left it there.

High Trim....My compression is about 80-82 psi. Not the best I know but have been told for this old thing that this isn't to bad. Yes, I meant .020 on the gap. No, I have not hooked my spark plug tester back up since I've reset the points. As far as punching the brass ring I'm still not sure about. I don't know what that does exactly. I had to re-shoot the video so it is still rendering and then I have to upload it again. Hopefully it'll show more than I can describe and possibly one of you will see/notice something that stands out. Please check back later to see it. Thanks

-B-

 

[Olias]

Re: Timing Problem? ( with video)

Ok guys...the video is finally uploaded. Take a look and tell me what you think.

-B-

 

[Joe Reeves]

Re: Timing Problem? ( with video)

I think you need to slowly reread my reply post #3...... tightening up the armature plate support, perhaps also the coil alignment.

You keep speaking about having the points just starting to open pertaining to the flywheel key is aligned with the fiber rubbing portion of the points. That IS NOT when the points just start to open.... that is the point where the point are to be set so that a .020 gauge will slide thru but a .022 will not.

 

[HighTrim]

Re: Timing Problem? ( with video)

Very hard to diagnose from here, but you may have a combination bad upper crank bearing and seal. If you grab the flywheel with the recoil off, is there fore/aft movement at all>>?

 

[Olias]

Re: Timing Problem? ( with video)

I think you need to slowly reread my reply post #3...... tightening up the armature plate support, perhaps also the coil alignment.

You keep speaking about having the points just starting to open pertaining to the flywheel key is aligned with the fiber rubbing portion of the points. That IS NOT when the points just start to open.... that is the point where the point are to be set so that a .020 gauge will slide thru but a .022 will not.

Hmmm....I'm pretty confused now. I thought I understood how to set the points but I guess not. I know how to gap them but where on the cam should I be to set the timing properly? I had asked you earlier about what exactly you meant by the "fiber" rubbing portion and didn't get an answer. Is that the little nob on the back side of the points that rubs/touches the cam as it spins, thus opening and closing the points? If so, aren't I supposed to have that fiber/nob lined up on the key on the crank shaft (which also means in the center of the keyway area on the cam)? If not, this is where I'm going wrong. I don't have any other marks or the word "set" on my cam. As far as tightening up the "support plate" goes, again I'm not sure what you mean. Loose how or in relation to what? In rlation to the main brass armature plate? It's held on by 2 long screws that go through the coil block/base and they are nice and tight, and then 2 other screws that are at the back end of the points base. Those are tight as well. I take it this is not what holds it tight?
As far as aligning the coils go, according to what I've read they look perfectly aligned. I can try and realign them but not sure how to go about it. Do you have a link that has some pics so I can see exactly how they need to be seated? Man, I'd really appreciate it.

Hope you understand that I'm not fightin' ya here. I thought I had done what you and others have described but sounds like I haven't. I swear it looks and sounds like the timing is off. I will look into the other stuff but I really need how to properly set my points as you are describing. Thanks again for everything.

-B-

 

[Olias]

Re: Timing Problem? ( with video)

Very hard to diagnose from here, but you may have a combination bad upper crank bearing and seal. If you grab the flywheel with the recoil off, is there fore/aft movement at all>>?

No, no slop or play.

-B-

 

[Joe Reeves]

Re: Timing Problem? ( with video)

I had asked you earlier about what exactly you meant by the "fiber" rubbing portion and didn't get an answer. Is that the little nob on the back side of the points that rubs/touches the cam as it spins, thus opening and closing the points? If so, aren't I supposed to have that fiber/nob lined up on the key on the crank shaft (which also means in the center of the keyway area on the cam)

Yes, that is correct.

 

[Olias]

Re: Timing Problem? ( with video)

Ok, so I did line up the fiber with the key on the crank shaft and then gapped them at .020. Can't get a .022 through and a .019 slips through ok. Sounds like I got that part right as far as the points are concerned.

On the subject of the support plate I guess I need to go find some info somewhere that explains exactly what it's purpose is. Maybe that will help me understand more of how and why it needs to be tightened. Same thing with the main brass plate. It has several holes in all 4 four positions and I don't have any clue as to exactly which 4 holes to use. I have just left it where it's been since I got it assuming it's in the right position. Guess that's it for now. Not sure what else to do. Tomorrow I will tear everything down to the support plate and see what's what. Thanks again.

-B-

 

[dazk14]

Re: Timing Problem? ( with video)

Quote Joe Reeves"Use a small amount of anti corrosive grease between the aluminum ring and the brass support plate and also on the brass bushing of the armature plate when all is well."

In the meantime, if your looking for a quick fix, use moly grease(chassis grease) black in color, generously, where Joe has noted above. That will eliminate much of the wobble at least for the short term. Quite often for the long term, or at least until you feel comfortable doing his modification.

The points... A quick way to find the high point of the cam is to find the point where the points are open the greatest. With the plugs out(so your not fighting compression) and a feeler gauge rotate the cam to what appears to be the high point against the rubbing block.

Insert a feeler gauge that is a snug fit into the point gap. With the feeler gauge inserted, rotate the mag plate(or cam) in both directions to see if the gap increases. Maximum gap will be the high point of the cam.

Mark the high point of the cam on top and you have your reference mark. No more torture.

Good Luck!

 

[AlTn]

Re: Timing Problem? ( with video)

Post #10 is the "tightening of the support ring" referred to. It is your"main brass plate". High has posted a pic depicting how and where.Get that procedure done and we'll move on to lync and sync and starting positions. Your vids and pics are very helpful, btw.