Johnson 9.9 Timing / Sync hash mark way off.

[louisvillefisherman]

I am attempting to set the throttle sync on my Johnson 9.9 as a step in diagnosing a larger issued I am currently having.

From what I have read, there is a hash mark on the top of the cam (found it) and it is supposed to line up with the roller when the pivoting action of the roller being pushed by the cam results in the butterfly just beginning to open.

My problem is that the hash mark is too far past the roller, maybe a 1/4 inch or so. I would have to turn the throttle way to much in the "power down" direction to be able to get that to line up and I cant because I am already at the lowest idle position on the grip.

I know there is an allen screw on the open end of the cam that essentially makes the cam "fatter" thus effecting when the cam hits the roller, but it does not seem to effect the location of that hash mark.

To visualize , if I were looking into the throat of the carb, the hash mark would be too far to the right of the roller. I would have to turn the throttle backwards (decelerate) quite a ways to get it to the center of the roller, but of course I can not because I am at the bottom end of the throttle twist range already.

What kind of problems would a poorly aligned throttle roller / hash mark create?

And what should I be looking at in order to get that line to come closer to the roller?

 

[Joe Reeves]

Re: Johnson 9.9 Timing / Sync hash mark way off.

What's the model number of that engine?

The allen screw simply moves the roller towards or away from the cam. The cam being the tapered portion attached to the timing base armature plate which has a scribed mark upon it.

It is normally a simply matter to have the timer base/armature plate rotated to a position whereas the scribe mark is in line with the roller.... and at that point, simply adjust that allen screw to touch the cam scribe mark.

If this cannot be accomplished, I would assume that something is not assembled properly OR there is a mixture of parts which should not exist.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

I am sorry, I should have included it. It is a J10RCCD, 1988 9.9 shortshaft.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Anyone have any ideas why my timing hash mark is a 1/8 to 1/4 of an inch to the right of my cam wheel?

My motor starts with 1 or 2 pulls, seems to idle smoothly but bogs horribly when throttled under load.

I was told to check my link sync and found that it is WAY off and there is no obvious way to adjust it other than the cam screw which only makes the cam fatter, and does not change its physical location. The only may to change the position is to twist the throttle but i cannot turn it far enough backwards to make the hash line up with wheel, it is actually to the right of the wheel, not the left like it should be.

Anyone?

Thanks!

 

[Joe Reeves]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Anyone have any ideas why my timing hash mark is a 1/8 to 1/4 of an inch to the right of my cam wheel? My motor starts with 1 or 2 pulls, seems to idle smoothly but bogs horribly when throttled under load. I was told to check my link sync and found that it is WAY off and there is no obvious way to adjust it other than the cam screw which only makes the cam fatter, and does not change its physical location. The only may to change the position is to twist the throttle but i cannot turn it far enough backwards to make the hash line up with wheel, it is actually to the right of the wheel, not the left like it should be. Anyone?/QUOTE]

You say "Turning the cam screw (allen screw) only makes the cam fatter". What does this mean (fatter)? Turning that screw should make the cam roller move either towards the back or front of the engine.

The terms "right/left" tell us nothing really. Example... left could be either side depending on where one is standing.

Standing in back of the engine, facing the spark plugs... Left is Port - Right is Starboard. Best to use these nautical terms to avoid confusion. As it stands, we have no idea which side that mark is on.

Bogging out (engine hesitates or dies out as throttle is applied) is caused by the throttle opening too soon in relation to the timing (scribe mark to roller) - OR.....

(All Metal Carburetor)
A fouled high speed jet which on that engine is located is screwed straight upwards into the high speed nozzle. When assembled, this jet would be extremely close to the bottom center portion of the float chamber.

(Carburetor w/Plastic Top & Plastic Float Chamber)
A fouled high speed jet which is screwed sideways into a plastic fitting at the bottom of the high speed vertical nozzle.

Which carburetor do you have?

 

[the machinist]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Someone may have changed carburetors & you could have an earlier one than was there originally. Most of the earlier carbs used a smaller diameter carb arm roller. This would explain why your mark is off as the carb's roller need to match the timing plate cam.

Does your carb have a plastic top? Usually these had a larger dia. roller. Or (at least on my 92) the rollers had a cream colored sleeve around the roller arm at the cam contact location. If yours is like this, possibly that sleeve became broken & fell off, creating the same conditions (smaller roller). Then on my 92 (which should be very close to your 88 carb) there is another Allen head screw on the carb roller arm base that you can do final adjusting of the sync timing.

You are right on the cam adjustment screw, it apparently is only for higher speed and does not really effect the timing mark.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Joe,

I'll clarify a few of your questions:

"What does this mean (fatter)?" - The cam itself (the black adjustable plastic wedge on the timing plate) has a screw. I am attaching a picture that I took from Leroy (thanks the machinist). The picture has a purple arrow which points to the screw that makes the cam (fatter). It has no direct effect on the "roller" other than changing the point in which the cam contacts the roller by virtue of its increase size as a result of turning this screw. The roller is on the carb, the cam is on the plate. (ignore the red and purple arrow, those are from Leroy's original use)

"Best to use these nautical terms to avoid confusion" - Sorry about that. The timing mark is always too far to the port side of the roller. At idle it is about 1/8th of an inch PAST port side of the the roller. Upon turning (increasing) the throttle grip, at the first sign of "butterfly movement" the arrow (which is supposed to be AT the roller now) is now about a 1/2 inch PAST port side of the cam.

Again, on the attached photo, I demonstrate where the timing mark is at during idle with a YELLOW line, and where the mark is at the start of the butterfly event is a GREEN line. As I turn the throttle, of course the timing plate turns toward port side (counter clockwise in photo).

As you can see, both my yellow and green lines (representing the positions of the timing marks at idle and butterfly movement) are port side of the roller making the alignment with the roller at butterfly movement event impossible.

According to everything I am reading, the timing mark that is embossed into the plastic cam should be just starboard of the roller, so that when you turn the throttle, the plate rotates to the port side, bringing the cam and its marking closer to the roller. Ultimately, if synced correctly this timing mark should be at the roller when the butterfly first moves.

I read elsewhere that possibly the throttle linkage just outside of the handle has some adjusting ability, perhaps a turnbuckle that may force the timing plate to move to a position that would allow the marking to be properly sync'd.

The Machinist,

Thank you for your wonderful guides. As you can see, I borrowed a picture of yours for demo purposes, I hope you do not mind. Allow me to address your reply:

I have a plastic top carb. My roller has the rubber sleeve perfectly intact. The carb according to the part #'s is the proper carb for this engine. It is the newer style plastic top with the integrated roller shaft versus the screw in shaft in the older style.

So fella's, how important is it for me to get this timing line sync'd to spec? I would like to fix it before I move onto my next problem, assuming this is an important step which I have read it is.

I am trying to diagnose a bogging down problem and I have been inside the carb more times than I care to. I am not ruling out more carb work, as I think the well assembly inside the bowl is a bit sketchy, more on that later.

Before I beat my carb into my skull tear and open yet again I want to either rule out, or correct this sync issue. I am trying to keep focused on one issue at a time as not to get overwhelmed.

A picture is attached, if anyone would like me to modify or add more reference to it please ask.

Thanks for everyones time. I know how valuable it is and I appreciate it incredibly.

Picture:

 

[Joe Reeves]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Okay.... You're speaking of a screw directly on the cam which makes final full throttle adjustments only, nothing else.

I am speaking of a screw that should actually be on the throttle cam roller itself, a short distance down from the actual roller. Adjusting this screw makes the roller move towards the rear or to the front of the engine. See item #20..........

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Yes, but the problem I am having is not with the roller position, it is with the hash mark on the cam. It is too far port side from the roller than it is supposed to be.

As I have observed, adjusting screw #20 will only result in the throttle plate opening or closing in relation to the roller lever position and will have no effect on the location of the timing mark.

If the timing plate would only move a few more degrees clockwise I would be in the proper range. But there is just no twist left in the throttle. I am at the bottom of the range. I even have the idle speed knob on the end of the tiller turned all the way down but am still 1/8 to 1/2 inch too far past the roller.

 

[Joe Reeves]

Re: Johnson 9.9 Timing / Sync hash mark way off.

On the end of the tiller handle is the mechanical idle adjustment stop knob... or at least that's where it's been on all earlier models. Back it off to allow the timer base to retard further.

 

[OptsyEagle]

Re: Johnson 9.9 Timing / Sync hash mark way off.

As I have observed, adjusting screw #20 will only result in the throttle plate opening or closing in relation to the roller lever position and will have no effect on the location of the timing mark.

It shouldn't matter whether you move the timing mark by moving the cam closer to the roller or the roller closer to the cam. The important issue is does the roller hit the cam at the mark? I don't have an engine exactly like yours but it would seem to me that if you can adjust the roller closer to the cam by adjusting screw #20 so that the roller hits the cam at the mark, then you are good to go. It also looks to me that you can obtain the same thing or some of that movement by adjusting the screw that the pink arrow is pointing to.

Just so that you know what you are doing here so you can diagnose if your problems are caused by this. Where the roller is when you are idling is not important. The reason you want the roller to hit the cam (butterfly just start to open) at that mark is because the spark timing of your motor needs to be adjusted for the various RPM ranges of the motor. As the cam turns it changes the timing of when the spark fires. Since spark is not exactly instantaneous (combustion takes some time to hit full power) you need it to fire sooner at higher RPMs then lower RPMs. OMC designed this timing advance by rotating the timing plate. It is sync'd with the carb, which determine the amount of gas and therefore RPMs.

So all that being said, if your timing plate is turning too far before the carb starts to open, your spark timing is happening too soon. It is possible that at the higher RPMs, the full power of your spark is happening before the piston is at top dead center and yes, this could cause some bogging. At best it would reduce your performance, but probably would not cause you much of a problem at idle.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Ok..progress!

I now have the throttle sync'd but I have not had an opportunity to test the motor yet as I spent all night getting it right and it was too late to fill the barrel and wake the neighborhood with full throttle testing.

Basicly I was able to turn the timing plate to its proper position by adjusting the trunnion (item #32 on attached schem). The throttle cable seems like it is too long as it was really difficult to get it to fit after I made the adjustment, but I got it! Had to remove pull starter and remove a clamp that was holding the trunnion in place. There is a threaded shaft that goes through the center of the trunnion ball. By turning the ball, it travels on the shaft thus adjusting the length of the cable. That cable length change is what allowed the plate to be able to rotate all the way to its proper low throttle position ultimately leading to the proper sync setup.

I now have the hash mark hitting the roller at the butterfly event. Awesome! Lets hope I can get it started and running tonight. (I am at work right now or I would be testing right now!)

So, for everyone's future reference, you can also adjust the timing plate position from where the throttle cable enters the engine compartment as it leaves the tiller.

I am wondering if this motor was once a remote and the previous owner (or some other party) hastily changed it back to a tiller and the person who did the change was unaware of the need or the procedure if syncing. They then started the motor, it idled and then they assumed the conversion was complete and proper when apparently it was not.


Picture:

 

[AlTn]

Re: Johnson 9.9 Timing / Sync hash mark way off.

glad you got it analyzed...it takes some fine tuning between the idle mixture screw and the idle speed knob on the end of the tiller handle to get the idle "right", at least it did on a '91 I fooled with. In gear and at wot, make sure your throttle plate < butterfly > isn't over rotating from horizontal. That " ignition cam screw" should allow you to adjust it so that it is horizontal at wot.

 

[the machinist]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Well, I had written this info as a added this option & ready to post, but the server was down for about 4 hours & would not accept my efforts. Glad you found it

Thank you for mentioning that you snatched my photo, as I was about to say your carb is wrong. If you go to my article where you snatched that photo, I show in another photo ahead of that one, the cam roller with a broken sleeve, that I refered to.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

I put it in the barrel this evening and started it. Apparently I have some more adjusting ahead of me. I thought it would be a simple but it became clear quickly that this is going to take a while.

At this point I am just guessing where I need to have the timing mark when I have the throttle all the way closed. I can sync the cam/mark with no problem, but the challenge I am having is where should that mark be at zero throttle.

So here is a question. Can anyone with a cam/timing plate like mine (1988 9.9) tell me how far from the roller your mark is at zero throttle? I now have the ability to move the timing mark pretty much where ever I want, and no matter where I put it, I am always able to make it sync. (if that makes sense), which tells me the combinations are infinite. So short of trying every possible combination, if someone could measure how far (in millimeters or something) the hash mark should be from the roller at zero throttle (grip turned all the way to the idle stop) this will give me a good position to start my adjustments from.

 

[the machinist]

Re: Johnson 9.9 Timing / Sync hash mark way off.

I just went out into the barn & looked at my 92. Without being able to give an accurate measurement without pulling the flywheel, I would guess at the lowest twist grip throttle position possible, the cam mark (looking from the rear) is slightly over 1/8" to the right (advanced) of the center of the roller

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Machinist,

Thank you! That is exactly the starting point I am looking for!

I am at work again today, but of I recall I currently have mine about 1/2 inch starboard from the roller which I now believe (and always suspected after I made the adjustment) that it was too far.

Another indication that I over adjusted was the fact that the neutral/reverse throttle lock now allows than 2/3's throttle turn before it stops. Before the adjustment there was no movement allowed. I bet it should be somewhere in between, perhaps 1/4 turn on the grip before neutral lock stop is hit.

If you happen to be out in the barn again (or if you can remember from memory) how much throttle movement (as in how far can you turn grip) when in neutral before you hit the neutral stop?

Thanks again, this is gold value info!

 

[the machinist]

Re: Johnson 9.9 Timing / Sync hash mark way off.

OK, another trip to the barn. With the shifting lever in reverse, the carb roller is centered on the small hole at the apex of the slot of the cam slot for the adjustment screw adjustment. The reason for the reverse setting is that I have lowered this neutral stop, leaving it just high enough to function for reverse.

The relationship of the twist grip indicator is just at the far (widest) part of the Vee's fasted speed indicator. However this may not really mean anything on your motor.

However I really think that unless your neutral stop is so far out of adjustment, that this would not make difference in any sync or carb adjustments

After your experience & that I have basically the same issue on a 79 that was a "parts motor" of the photo you copied above. I have changed/added to my OMC 9.9 carb/fuel pump repairs article. Check it over & if I need to make changes let me know.

 

[louisvillefisherman]

Re: Johnson 9.9 Timing / Sync hash mark way off.

Thanks Machinist.

The reason I was asking about your neutral stop is so when I dig back into the trunnion, I need a few points of reference as to how much adjusting it needs. Basiclly how many times I turn the trunnion ball. Right now I have the trunnion turned too far up the threaded shaft. I figured between knowing where your hash mark is at "no throttle" and how much twist you have until you hit the stop, I should be able to get it into the neighborhood.

You see, right now my throttle has more "travel" than I think it needs. When I say travel distance I am meaning the amount the throttle cable that moves when turning the grip. So instead of turning your grip say 1/4 turn before the mark hits the roller, I am turning maybe 3/4. Considering your mark is at 1/8th inch at no throttle, and mine is more like 1/2, I am way off.

I will be making the trunnion adjustment to bring the timing mark to around 1/8 inch before hash at no throttle and then resync tonight and will report back.

 

[barboxbrat]

Re: Johnson 9.9 Timing / Sync hash mark way off.

I put it in the barrel this evening and started it. Apparently I have some more adjusting ahead of me. I thought it would be a simple but it became clear quickly that this is going to take a while.

At this point I am just guessing where I need to have the timing mark when I have the throttle all the way closed. I can sync the cam/mark with no problem, but the challenge I am having is where should that mark be at zero throttle.

So here is a question. Can anyone with a cam/timing plate like mine (1988 9.9) tell me how far from the roller your mark is at zero throttle? I now have the ability to move the timing mark pretty much where ever I want, and no matter where I put it, I am always able to make it sync. (if that makes sense), which tells me the combinations are infinite. So short of trying every possible combination, if someone could measure how far (in millimeters or something) the hash mark should be from the roller at zero throttle (grip turned all the way to the idle stop) this will give me a good position to start my adjustments from.

Hello, I have the same year, model motor and carb that you have. To answer your question.......my motor is set to where the cam mark hits dead center of the cam follower or roller with no gap. If you have a gap at this setting it will cause the motor to hesitate under a load. Check the cam follower roller and make sure it is not missing the clear rubber coating on the roller.