Topic: Tappet valves messed up?

[Ayrity]

So I got the cover off my points and I moved the plate to show 1 and 4 T aligned and my 1 cyl valves were tight, I got them to both me loose when I aligned the 2 and 3 T mark and the valves needed a bit of adjustment but not much. My question is, is it more likely that my valves are timed right and the plate is just off to show 2 and 3 when it should be at the 1 and 4 mark? Or could my timing be that off and still be rideable? Because it sounds a bit noisy in the head but has good power. I also tried to adjust the cam chain put 1 at tdc with the valves loose and rotated 15 degrees I think and loosened and then retightened the adjust bolt. I didn't feel or hear anythin move. How do I know it worked for sure? Thanks

[OldSchool_IsCool]

Realize that the cam turns 180 degrees when the crank turns 360.  If you are at the F1.4 mark and both tappets for #1 are tight, turn the crank another full 360.  Your #1 tappets should now be loose and ready for gap check/adjust.  Also hit the #2 exhaust and #3 intake while your there.  Another 360 of the crank and #4's tappets will be loose.  check/adjust both #4 and #2 intake and #3 exhaust.

P.S.  I'm writing this from memory, so I'm not 100% sure if I have #2 and #3 correct.  Follow your manual if it is different.

[Ayrity]

I do understand all that, and thanks for the answer, but I really think my bike is showing signs of having piston one being at tdc when the 2.3 T mark is aligned. and also if someone could let me know i should hear or "feel" anything when i do the cam chain adjustment?

[OldSchool_IsCool]

Hmmmm I'm not sure if the registration marks CAN be mounted 180 degrees off.  What bike is this?  And you said it runs, right?  Is the BLUE points wire connected to the 1.4 points (left set) and does the BLUE wire feed the coil that sparks cyl 1&4?

[Ayrity]

I will check in the morning and let you know. its a 76 cb550k.

[750goes]

you probably would not hear anything from the camchain adjustment - unless it was really slack..

check those valves - don't mess them up...

[MCRider]

Realize that the cam turns 180 degrees when the crank turns 360.  If you are at the F1.4 mark and both tappets for #1 are tight, turn the crank another full 360.  Your #1 tappets should now be loose and ready for gap check/adjust.  Also hit the #2 exhaust and #3 intake while your there.  Another 360 of the crank and #4's tappets will be loose.  check/adjust both #4 and #2 intake and #3 exhaust.

P.S.  I'm writing this from memory, so I'm not 100% sure if I have #2 and #3 correct.  Follow your manual if it is different.

You are correct OldSchool.

And to answer his question, if the bike was running there is no way that the timing indexes can be off.

If you're on T1-4 and the #1 tappets are tight, take a look at number 4, they should be loose. AND both 1 and 4 will be at TDC. Its just that the cylinder with the tight valves is on the exhaust stroke and the one with the loose tappets is on compression. IF you loosen the tight ones enough to "adjust" them it will be really noisy on start up as they will be WAY TOO LOOSE.

Carry on, carefully. You may not be grasping the mechanical relationships here.

[Ayrity]

thanks for all your help guys, but I do understand what is going on. I did align the 1.4 T mark but the ONLY cyl with 2 loose valves was the number 2 cyl. I dont have stock points, so I was wondering if it's possible that whoever took the points area apart, put the adjustment plate with all the tickmarks on it back incorrectly. Also, the bike still seems like it is sounding "rattley" in the top. Its at this point I wish I had more experience, because I would know if i did a bad job adjusting the valves (I really dont think I did though...) or if the cam chain is really loose and the tensioner is not working...

[Ayrity]

ok, so i couldnt wait for morning ha. I checked and yes the blue wire from the points do connect when the 1.4 T and F marks are in the viewer window. But I checked AGAIN and when the 1.4 mark is aligned, I either have #1 both valves tight and #4 only one tight OR the other way around. never ever ever even when turned 360 do I have both valves loose when the 1.4 mark is aligned. I get both #1 (or #4) loose when the 2.3 T is aligned. Something is def up with this engine then. It runs well, so I think everything is put together running-wise correctly.

I am just so confused at this point as to why I cant get both intake and exhaust valves on #1 or #4 to be loose at the 1.4 T mark! arh! Could my cam shaft be installed incorrectly? or (just thought of this) maybe it is adjusted to the advanced spark mark?

by the way I did trace the blue wires all the way to #s 1 and 4 and yellow to #s 2 and 3 in case you were gonna ask about that.

Another update: Just took out the spark plug for the #4 and used an unzipped zip tie to feel when the piston is at tdc, and sure enough, it is at tdc when the 2.3 T mark is aligned. WTF does this mean? Where do I start with this weird problem? The only thing I can think now is that the cam shaft was installed incorrectly by the PO. Does this mean I'm just barely running this engine somehow? I dont see how, I just took it for a 3 hour ride with no problems! The top end DOES sound really rattley though. Sorry for all the info and questions I am just completely lost on this one... Help please

[Ayrity]

ok again with the sorrys for so many posts... It is just driving me nuts, and I think maybe after a long long night, I've figured it out. Below is a picture of what my points look like. I daresay that this replacement set of points came with a viewer window on the bottom, but our bikes have the view at the top, so this was mounted with the window at the top. Thus showing 2.3 T when in fact 1 and 4 are at tdc. I traced the combustion sequence in my head with the tappet covers off and the plug removed so i could folow along with where the piston was at the time, and it went smoothly. (intake and exhaust are loose and piston is at tdc, intake goes tight piston moves to bottom, intake gets loose, piston moves up, points for 1.4 make contact, piston moves down, then back up, exhaust gets tight as it moves up, then gets loose again and back to step one with both tappets loose and piston at tdc) This to me means that the aftermarket points and its viewer window are just screwed on to show the wrong marks. Thoughts?

[w1sa]

Yes. If every thing else is in sync/sequence, the rotating index/ plate position being out of place 180deg to fixed timing index would cause that situation....imo.


Edit: BTW, that picture was not visible when I posted. The breaker plate appears to be off a later CDI ignition and I think the crankcase mounting side would be opposite to yours. That might explain the index mark/1.4 timing anomoly, as you see it.

[Ayrity]

thanks so much w1sa! you have no idea how good that is to hear... whew. Hopefully ill get a couple more posts just like yours telling me I was chasing a problem that doesnt really exist. better to have wasted time trying to find a problem thats not there than ignoring one that might be right?

[w1sa]

Another thing to be mindful of, is that a timing plate has its advance marks ahead of the T mark (TDC).

If a timing plate comes off a left side crankshaft mount and is positioned on the right side of the crankcase, then those same advance marks will trail (incorrectly) behind the T mark in rotation. The timing plate you have installed may or may not correctly match the bikes timing requirements, so check the rotational correlation to the expected firing position before you "set and forget".

[MCRider]

thanks for all your help guys, but I do understand what is going on. I did align the 1.4 T mark but the ONLY cyl with 2 loose valves was the number 2 cyl. I dont have stock points, so I was wondering if it's possible that whoever took the points area apart, put the adjustment plate with all the tickmarks on it back incorrectly. Also, the bike still seems like it is sounding "rattley" in the top. Its at this point I wish I had more experience, because I would know if i did a bad job adjusting the valves (I really dont think I did though...) or if the cam chain is really loose and the tensioner is not working...

my apologies. Interesting problem. Seems like you've got a lot of help here, Im sure you'll figure it out.

[Ayrity]

no prob MC, I know you were just lookin out to solve the problem and not to slam me As always yes, lot of good help here, you included.

[MCRider]

no prob MC, I know you were just lookin out to solve the problem and not to slam me As always yes, lot of good help here, you included.

That's right, thanks.