Author Topic: Embarrassing headscratcher (Read 2814 times)

Ecosse · « **on:** July 08, 2008, 08:21:01 PM »

I'm trying to adjust valves on my 550 and if I had any hair I'd have pulled it all out by now. I know, it's a no brainer (I've done many to cars successfully- but not in years) so let me explain.

I've followed the steps perfectly (I thought) as outlined elsewhere in the forum. Put it at TDC for #1, and seemed to be able to slip in the feeler and set exhaust clearances for the exhaust side. #1 intake is another story; I could not get the feeler in, after much rechecking to be sure that it was on TDC and inserting the feeler from different angles... still no go. I thought maybe the valve was adjusted (by whom?) too close so I backed it off a bunch and still NO GO.

Understand, I checked and rechecked my steps so many times I lost count; spinning the engine over and rechecking and on and on. Thought well maybe I don't have #1 at TDC so I'll move onto number four cylinder. Similar experience- although as I type I can't remember if the clearance issue was with intake or exhaust valve.

Now, I have monkeyed so much with it I am looking at a bike that is further from running than when I pulled it into by friend's shop. For the love of Christ what am I missing here?! A problem so frustrating (and it has been) must be due to something simple I'm overlooking, not doing, or doing wrong... right?

A blow to the ego this is... someone save what little sanity I cling to! $:-\$

Hush · « **Reply #1 on:** July 08, 2008, 08:31:13 PM »

Areyou timing on the "T" or the "F" mark?
Different marks for different reasons.
"T" for cam valve timing and "F" for firing the spark plugs.
Maybe I'm preaching to the converted but I thought I should ask.

mattcb350f · « **Reply #2 on:** July 08, 2008, 08:36:18 PM »

You were checking the clearance on the wrong cylinder. T mark on 1.4 for cylinders 1 or 4 but you actually have to check which one of them is on TDC for the compression stroke.

While one will be, the other one will be between exhaust and intake stroke causing the problem you have.

role the engine over while watching the valves, and looking at the marks on the advancer unit and you will see that one of the sets of valves on either pair of cylinders (1 and 4, or 2 and 3) will be working the valves. The other won't, and thats the one you adjust first.

Then, role it over 180 degrees and do the other.

Confused...... I am a little

Matt.

Ecosse · « **Reply #3 on:** July 08, 2008, 08:44:31 PM »

Thanks guys. Matt, without even looking at the motor it sounds like you're onto something.

I'd spin the motor around while watching #1 intake rocker go down, then begin to go up. At that point I'd watch for the T mark and stop there. It looked as thought both valves were in the closed position and thought I was golden.

Just so I'm clear: the 1.4 you reverence IS the T right?

mattcb350f · « **Reply #4 on:** July 08, 2008, 08:52:26 PM »

the 1.4 is marked on the advancer unit, along with 2.3; indicating top dead center on either 1 and 4 cylinders or 2 and 3 since they travel in pairs.

As the cylinder comes up on TDC, there should be no valve movement at all. Say on cylinders 1 and 4, as you turn the engine over and the pair of pistons start to come up, one will be exhausting some gases and the other will be building compression. The one exhausting will have opened the exhaust valve and will nearly close at TDC while the other won't move the valves at all.

You can see this if you watch all the rockers in action through the tappet covers and then you can tell which one is on the compression stroke.

Kind of hard to explain, I set the engine to TDC and then put my wrench on the special nut pointing vertically to remind me where TDC is. Then, rotating the engine over (Clockwise) I can watch the rockers while feeling where the wrench is so I know when Im comming around to TDC again.

mrbreeze · « **Reply #5 on:** July 08, 2008, 09:00:52 PM »

But..........Its so F%$@N confusing!!!!!!!!!!!!!!....... It really isn't

jmckinne · « **Reply #6 on:** July 08, 2008, 09:46:39 PM »

Ecosse-

It's easy to find which one is at TDC: Both valves will have play in them. Whichever cylinder of the pair you are at "T" for (1 & 4 or 2 & 3) has loose exhaust and intake valves at the same time is at TDC. Just wiggle the rocker arms.

If a cylinder isn't at TDC one or both valves will have tension on them and they won't wiggle at all.

Ecosse · « **Reply #7 on:** July 08, 2008, 10:38:12 PM »

JM,
Yeah that's what I thought and I had spun the critter around a few(!) times looking for the slack in #1 int/exh. Somehow I missed it and that's what had me thinking someone may have set the clearance too close for the intake. Far fetched I know but I was at a loss and my frustration level didn't help.

Now that I, the all knowing mechanical genius, have messed up the clearances I don't know how exactly to undo my "craftsmanship".

But at least I know now that somehow I missed TDC. How to remedy my problem is another matter.

Thanks for the input all. Thanks for rubbing it in Mrbreeze.

You spelled F#@%ing wrong. A Skynyrd fan?

TwoTired · « **Reply #8 on:** July 08, 2008, 10:53:50 PM »

Take out #4 Spark plug. Put finger over hole.
Turn the crank in the run direction. When the engine pushes your finger off the hole, you are on the compression stroke. When the T mark aligns, set your tappet clearance.

Turn the crank 360 till the T mark aligns again. Adjust #1 tappets.

You can do the same procedure to do #2&3. Or, align the T mark and adjust the either 2 or 3 based on loose tappets. 360 crank turn, adjust the remaining cylinder's tappets.

Cheers,

Ecosse · « **Reply #9 on:** July 08, 2008, 11:16:58 PM »

Thanks TT for helping me dig outta this hole I made for my self.

I'll try to use my head a little more for the next chore.

mrbreeze · « **Reply #10 on:** July 09, 2008, 06:35:48 PM »

Quote from: Ecosse on July 08, 2008, 10:38:12 PM

JM,
Yeah that's what I thought and I had spun the critter around a few(!) times looking for the slack in #1 int/exh. Somehow I missed it and that's what had me thinking someone may have set the clearance too close for the intake. Far fetched I know but I was at a loss and my frustration level didn't help.

Now that I, the all knowing mechanical genius, have messed up the clearances I don't know how exactly to undo my "craftsmanship".

But at least I know now that somehow I missed TDC. How to remedy my problem is another matter.

Thanks for the input all. Thanks for rubbing it in Mrbreeze. You spelled F#@%ing wrong. A Skynyrd fan?

Sorry man!!!!.....A Skynrd fan?.....Oh hell yeah!!!

scondon · « **Reply #11 on:** July 09, 2008, 06:49:38 PM »

Quote from: mrbreeze on July 09, 2008, 06:35:48 PM

Quote from: Ecosse on July 08, 2008, 10:38:12 PM
JM,
Yeah that's what I thought and I had spun the critter around a few(!) times looking for the slack in #1 int/exh. Somehow I missed it and that's what had me thinking someone may have set the clearance too close for the intake. Far fetched I know but I was at a loss and my frustration level didn't help.

Now that I, the all knowing mechanical genius, have messed up the clearances I don't know how exactly to undo my "craftsmanship".

But at least I know now that somehow I missed TDC. How to remedy my problem is another matter.

Thanks for the input all. Thanks for rubbing it in Mrbreeze. You spelled F#@%ing wrong. A Skynyrd fan?
Sorry man!!!!.....A Skynrd fan?.....Oh hell yeah!!!

What's a Skynrd, Fred?

Ecosse · « **Reply #12 on:** July 09, 2008, 07:17:30 PM »

Quote from: scondon on July 09, 2008, 06:49:38 PM

What's a Skynrd, Fred?

It's a high school gym teacher... if memory serves.

Oh, and theme music to my more 'rambunctious' days.

mrbreeze · « **Reply #13 on:** July 09, 2008, 07:40:06 PM »

Quote from: Ecosse on July 09, 2008, 07:17:30 PM

Quote from: scondon on July 09, 2008, 06:49:38 PM

What's a Skynrd, Fred?

It's a high school gym teacher... if memory serves.

Oh, and theme music to my more 'rambunctious' days.

Correct you are!!!!!!....Yeah,they were quite the sh!t back in the mid 70's......I seen em twice before plane crash.....they were truely one of a kind.

Buber · « **Reply #14 on:** July 09, 2008, 11:35:00 PM »

Back to the topic - after few tries with TDC, now I'm seeting my valves little bit different. Which is - looking at the lobe, it should have the same gap all the way, except where is the protrusion to push the rocker. So, for exhaust valve, I will set the inlet valve at it's highest point, an then i know, that ex valve lobe MUST be at the low point. And here I set the gap.
Since on mine CB650 I have better acces to regulation, I do it in the following way. Say, ex valve needs checking. It should have 0,08mm so i put 0,08 feeler under the rocker and turn the crankshaft tugging slightly at the feeler, and there comes a moment when it starts to move. This is the spot where I set the tolerances. IF the 0.08 doesn't move (say, valve is too tight) I will use 0,07 and do it again. If valve is too loose, I will use 0.09 to find the "sweet spot".

I hope, I made myself clear...

This method worked ALWAYS for me.

Ecosse · « **Reply #15 on:** July 09, 2008, 11:51:01 PM »

Very interesting Buber. I think I understand what you're describing... but don't hold me to that!

Also, I'm not very familiar with the 650, although I am intrigued, the cam cover/top end looks different then that of the 550, yes?

I've not seen a 650 up close and wonder what Honda did differently. I suppose that's for a new thread though.

Thanks for the input. I plan on another go Thursday.

mattcb350f · « **Reply #16 on:** July 10, 2008, 08:05:20 AM »

Quote from: TwoTired on July 08, 2008, 10:53:50 PM

Take out #4 Spark plug. Put finger over hole.
Turn the crank in the run direction. When the engine pushes your finger off the hole, you are on the compression stroke. Cheers,

Of course!

I never remember that one. It's fool proof

Matt.

mrbreeze · « **Reply #17 on:** July 10, 2008, 07:01:32 PM »

Over many years of wrenching,you will get a feel for valve adjusting. The important thing is to adjust them off of the lobe. If you don't do it right......Its better to be too loose than too tight. Some publications tell you to align timing marks and adjust certain valves. Then rotate crank 360 degrees and adjust the rest. Thats OK but make damn sure you are on the right stroke to start with. Don't always trust the book anyways......they used to tell you to crank down Chevy hydraulic lifters one turn after contact. It should actually only be 1/2 turn. If you put on your thinking cap while you are turning the crank and watching the valve action.....it is very obvious when you are at the right spot to make an adjustment.

Ecosse · « **Reply #18 on:** July 10, 2008, 07:54:22 PM »

Thanks Mrbreeze,

Took another stab at it today but had to leave my buddy's shop so I didn't button things up. It took a while since I had to undo my earlier handiwork but I think they're set now. I'm rechecking my work tomorrow and keeping your suggestion in mind about better to be loose than too tight.

I thought about it and it's been almost twenty years since my last tappet adjustment- 225 slant six!
It's been 10 years since setting points or working on Carter AFB's! I'm so ashamed for losing the touch.

Actually, part of the reason for getting a bike older than most of my girlfriends is to get back into things.

I really appreciate the help all.

mrbreeze · « **Reply #19 on:** July 10, 2008, 08:02:48 PM »

Glad to be of service.......get that bugger runnin and go out & enjoy the summer!!!!!

News:

Author Topic: Embarrassing headscratcher (Read 2814 times)