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Timing and points question on '68 350

2537 Views 15 Replies 5 Participants Last post by  tbpmusic, 
MNellis
I'm looking for a little help on setting the points and timing on my '68 350. I've got the official Honda 250/350 shop manual but I guess back then English translation wasn't quite up to speed based on all the typo's and grammer. :lol:

The manual correctly states to set the point gap first but as I read on it 'seems' to state that the timing for each cylinder can be set independently. I do not see how that is possible so I'm guessing it's not.

I done a search but haven't come across a detailed explanation of how to set the points and time the thing.

So far here is what I've done.

I removed the stator cover and using a 14mm wrench I rotated the motor until the foot of the point is over the mark on the point cam. I'm assuming the highest lift location for the point. After using my wife's nail file, I set the gap at .014 then cleaned with contact cleaner. I performed the same thing on the second point.

Next I attempted to set the timing. I connected a 12v tester light (although a volt meter would have worked just as well)and rotated the motor until the light just came on (point starting to open). Per the manual, I adjusted this "on" point to the LF mark on the rotor.

The manual goes on with a "Note": it basically says that the advancer can be checked with a timing light. It should be 30 deg before the 'F' and 'LF'. Are the marks they're talking about the 'T' and 'LT' marks? If so, then shouldn't I be setting the initial timing using the 'T' and 'LT' marks (TDC/LTDC)?

Does this method seem proper?

The points were a little tight on one side and a lot tight on the other. I was having a problem with the bike not starting quickly and it wasn't pulling past about 7500 rpm very well. I haven't had a chance to ride it since making these adjustments but I'll post up how it goes.

Unfortunately, I also took this opportunity to pop the oil filter cover off and clean it out. After not having been off since about 1982 or so it took a little doing and of course I damaged the gasket. The Honda shop says these are no longer available (although all the other case gaskets are avaliable except the timing chain adjuster gasket).

What are others doing for a gasket on this cover? Making your own? Silicon gasket sealer?
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tbpmusic
Turn the alternator until the left point is as wide open as it gets.
Set the gap here to 0.013". Don't bother gapping the right point.

Hook up your little static-timer bulb, rotate the alternator until you feel/hear the left cylinder come up on compression stroke. If you stick your finger in the spark plug hole, you'll hear/feel a "swoosh" of air as you come to the top of compression stroke.
Rotate the entire point plate until the light bulb comes on EXACTLY at the "LF" mark.
Now turn the alternator and adjust the right point gap until the light comes on EXACTLY at the "F" mark. Don't worry about what the gap is on the right exactly - it is what it is, there's nothing you can do about it. Hopefully it's somewhere close to the right value.
Remember, set the left side timing by rotating the entire point plate - set the right side timing by adjusting the right point gap.

If you have a strobe, when you open the throttle, the timing should "advance " to somewhere between the (unlabeled) two marks.
You will get oil all over you and your little strobe light.

The photo shows a CB200 alternator, it has only one set of points/marks. Your alternator will have two sets of marks.
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MNellis
Thanks for the detail tip. It sounds like you've spent some time around the Honda Service Bays.

I'm a little concerned about using the "....is what it is" method to gap the points but I'm willing to give it a try. Back in the early 70's I spent a LOT of time under the hood of our race cars trying to get the dwell right so this concept is a little foreign. It makes a little sense since the timing is more important that the dwell.

After I get the gasket installed for the oil filter cover I'll fire it up and give it a shot.
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tbpmusic
Well Mike, there's nothing you can do about it, that's the procedure.
It truly is what it is. Or will be what it will be......


That's definitely the correct method for setting the timing on these beasties. There's simply no other way to do it. That's why no one here has jumped in to correct me, it's the way it's always been done, and the way we all do it.
Don't mean to sound pompous or didactic, but if you ever run across a better way, be sure to let us all know......

You can check (not adjust) the gap after you're done, and if the points aren't too worn and the point plate is somewhere near the center of its range, the gap will usually come in somewhere within the allowable range. (Clever, these Japs)

So if you follow this method, your 350 should run pretty good, barring other problems.

Incidentally, I use an old dwell meter too, not a feeler gauge.
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tbpmusic
Mike -

A bit more on this....

There are two versions of the Honda 350 Manual floating around out there, I just looked at both of them.
The earlier manual is pretty vague about this procedure - I suspect that's what you are looking at.
The later manual is much more specific about this, and details the exact method I outlined above.
Here is a link to the page in question....

http://home.comcast.net/~tbpmusic6/ExtractPage2.pdf

This is just an axample of the conflicting info that different versions of the manuals may present - you have to be careful.
Generally, the older manual is more accurate, but in this case, the newer manual is correct.

I hope this soothes your troubled brain a bit - I didn't just make it up....
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MNellis
Bill, thanks for the follow-up. The link you posted to the procedures is totally different that what I have. Other than just mentioning a timing light, my manual doesn't say anything about it. And, as you say, my manual is very vague on setting the points and doesn't have near the detail.

Please don't misconstrue by comment as questioning the procedure you mentioned. In fact I went right out to the garage and used the method you outlined and it worked great. My manual doesn't even mention a light bulb to check the points but that's what I used and it's actually pretty accurate. The left cyl points were pretty tight so I used .014 as the point gap and the left cyl timed correctly, staticly. I also set the right side at .014 as a start. I then fired up the motor and it seemed to start a little quicker and idled nicely. I was glad to see there wasn't a bunch of oil coming from the stator. I was pleasantly surprised to see the LH timing was spot on! The right side was about the width of the pointer off so I left it along thinking I probably couldn't get it much better. I tightened everything up, did a final check and let the bike warm up. The throttle response seemed a little crisper and everything sounded and felt good. I would have taken it for a ride around the block but the foot rest bracket is off for powder coating right now.

Instead, I spent today sourcing some gasket material to make a gasket for the oil pump cover that was damaged when I cleaned the oil filter the other day. I found some good material at Advanced Auto Parts and made a nice gasket that I outline here.. for those interested.

http://picasaweb.google.com/6453635/MakingAGasket#
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johnnyc14
Nice job Mike! It's sometimes hard to find gasket material these days.. I bought a complete overhaul gasket for my 450 set on ebay for about $30. The quality seems OK.
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WOZERD
WORD: Yo--Bill be right. (and righteous!)

Alternately, in the absence of a test light or other high tech devices, a cellophane wrapper off of a cigarette pack can be used. Insert the cellophane between the points when they are obviously closed. Test the amount of pressure required to pull the cellophane from between the points. You want to exert just the right pressure to get the cellophane to move. This gives you a feel for the pressure required, then use just the tiniest amount LESS pressure to tell when the points open. Then, rotate the crank to the correct mark, apply that very fine and small amount of pressure to the cellophane and rotate the points backing plate til the cellophane just begins to slip out from between the contacts. Also, you can use a cardboard match stem to set the gap. It must be in good firm condition.
If you are ever far away from civilization this works. Or, if like me, you just can't find your D*mn test light! Or if your battery is dead or-- if you have a tendency to step on your test light-- OR, if the last time you saw it, it was being removed from your right front car tire by some tire store guy.
I was taught this method by a Triumph mechanic who claimed it made him a better lover. But that was in the early 70's and drugs were much more prevalent.
The cellophane also works well to determine the moment of contact on your carb idle screws. After you synchronize your carbs, slowly screw the idle screws in til the cellophane is held tightly. Then, applying that same small pressure, pull on the cellophane while slowly backing out the idle screw-- do not push down on the screwdriver!!. Just as the cellophane begins to slide out, you have found the "starting point". Do both sides then turn each screw in equally until proper idle is found.
Maybe I should have another cup of coffee before I post this. I just woke up and so far have only had one.
What the heck, throw caution to the wind!
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tbpmusic
Glad to help.
Back in The Day we used a cigarette rolling paper if we didn't have a bulb.
But you can get arrested for buying those these days......

I'm pretty sure I've posted links to BOTH the 350 manuals here in the past, and did send Jason (our site administrator) cd's full of manuals to make available to members here.
When he has time, I'm sure he'll make them all accessible to you.

As I get time this week, I'll post another link to the newer 350 manual.
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MNellis
tbpmusic said:
You can check (not adjust) the gap after you're done, and if the points aren't too worn and the point plate is somewhere near the center of its range, the gap will usually come in somewhere within the allowable range. (Clever, these Japs)

So if you follow this method, your 350 should run pretty good, barring other problems.

Incidentally, I use an old dwell meter too, not a feeler gauge.
Click to expand...

I found the manual you referenced on another part of this site. I didn't pay much attention to it in the past since I figured I had the "official" Honda Factory manual. This other manual is much, much more complete. I especially like the the cutaway diagram of the motor.

I've been looking for an old dwell meter (mine is long gone) just for the this bike. If I recall, didn't those meters have 4,6 and 8 cyl selections? How do you get it to work with 2 cyl. I seem to recall using one on my dad's bike as a teen ager but that was almost 40 years ago. Is my memory correct when I say that 32 deg of dwell is the number?

I've been racing and riding modern bikes too long. I forgot what it was like to actually have to tune a motor without a computer connection.
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M
hi all.
sorry to revive an old thread but i had a stupid question on how to hook up my dwell meter. I have a black and green lead. black to ground and green to the coil, right? well with the tank still on its tough to completely see but Im not sure where on the coil to hook the green lead can anyone help me with this?
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tbpmusic
Mike7202 said:
hi all.
sorry to revive an old thread but i had a stupid question on how to hook up my dwell meter. I have a black and green lead. black to ground and green to the coil, right? well with the tank still on its tough to completely see but Im not sure where on the coil to hook the green lead can anyone help me with this?
Click to expand...

An old-school dwell meter (I use one) goes from the points to ground.
Don't know which color is which for you - just try both ways till you get a positive deflection of the needle.
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M
thanks for the tip. it appears that my old school dwell meter might be broken as i dont get a dflection either way
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tbpmusic
Mike7202 said:
thanks for the tip. it appears that my old school dwell meter might be broken as i dont get a dflection either way
Click to expand...

The engine is running, right??
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M
ha ha yes the engine is running. i stuck the black cable on one of the cylinder cooling fins and the green on the little nut on the bottom of the left point. nothing, switched them-nothing. on several different places on the point. tried each combination on dwell, tach, and volts. nothing. looked for an on/off switch of some sort on the dwell meter- nothing. i may have to look for a new dwell meter.
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tbpmusic
Sounds like it.
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