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Top end rebuild problems

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2.8K views 21 replies 6 participants last post by  DD23  
#1 ·
Hello everyone, I redid my top end put everything back together and decided to adjust the valves while the motor was out of the bike. On the left side I went to the LT Mark and made sure I was a top dead center. I wanted to adjust my valves so I adjusted the intake on the left side. When I went to adjust the exhaust valve on the left side, it was so tight I couldn’t move the adjusting screw.
I must have something 180 out of whack. I went to the right side turned my motor 180°, so that the right side was a top dead center and the same thing. The intake valve would adjust but the exhaust valve was so tight on the spring equinox adjust.
Any help is appreciated. I’m no expert in learning as I go must’ve done something wrong.
 
#2 ·
Did someone re-cut the exhaust seat, and sink the valve farther into the head ? If so, the end of the valve stem will have to be tipped(shortened) to make up the difference in height . At least you haven't installed the motor yet.
 
#5 ·
Nope nothing weird to the valves. Put them back in the way I got them. And you’re absolutely right at least I haven’t put the motor in the frame yet that would’ve been a nightmare.
 
#3 ·
Hi zen,

Can you post a picture of the two adjusting shafts ends for the left cylinder, and same for the right cylinder please ?

It's always best to state your exact bike in a post, saves confusion.

Never heard the term equinox in relation to an eccentric, but I suppose it is a turning point of sorts. Soon be going up hill again, roll on summer, it's cold here and Gunna get colder !

Dd23🎅
 
#6 ·
LT must be on compression stroke .... sounds like you are on LT exhaust stroke.

Make sure the marks on the end of the shafts are pointing out when adjusting the valves.
Nope I checked and re-checked LT compression stroke for sure. The intake can be adjusted without a problem. The exhaust is right up against the valve. No wiggle room at all. I wonder if I could have put the cam in 180° wrong
 
#8 ·
Rotor at LT
Pin up on cam, line on cam gear horizontal with case. Make sure the bolts are in correct hole or you are buying a new cam. This is for cam install, not setting valves.

Bring the cam around so the pin is at approximately the 5 o'clock position. This is where there is the least pressure on the cam. Left intake, if I remember correctly will still have some pressure. Check clearances. What do you have?
 
#9 ·
Thank you I must have let the lt mark move . Ok I did that .pin is at five o clock. Now I can adjust both intake and exhaust. but the lt mare is not near where it should be and Im not at TDC.
 
#10 ·
Just put it on the LT mark, if both valves aren't loose,(top of the exhaust stroke) roll ahead one full turn to LT once more, (top of the compression stroke) then adjust the valves.
 
#14 ·
Picture....

Cheapo internet phone...

Take pictures, saved automatically....

Open thread, click the "paper clip", select pic and wait, once loaded press insert, still learning myself...

Those eccentric valve adjustment shaft marks are important.
 
#15 ·
Image
Image


Image

Sorry for poor quality, no means to post a scanned image.

Info up to 73....

Paper clip method works for me but a but slowly. Maybe you need more posts to be allowed to post pictures ?

If your still having problems, maybe remove all rockers and shafts, set to Lt tdc both cam lobes to "closed valve" position for left cylinder, refit those rockers.

Repeat and set up for right cylinder.....

Don't rush, be carefull, do it correctly so drama free.

Dd23🎅
 
#17 ·
So I was able to work on my motor again today. I checked everything everybody on this forum had suggested. I even move the cam 360°. Nothing seems to work. When I get it all buttoned up three of the valves are adjustable and one is always so tight. I can’t turn it.
I posted some pictures. Hopefully I did it right. Due to the forum and just learning. If anybody sees anything obvious that I’m doing wrong, please let me know.
thanks for any help
 
#18 ·
Strange the rotor is stamped 175, all the 350 engines I have worked on had 286 stamped on them.

I have seen the key and key way for the rotor be worn and causing issues.

If you are rotating the engine with the top off then you should stack some washers on 2 of the studs and tighten them down snug.
 
#19 ·
Do you have the cam chain tensioner in when you are turning the engine over? bad things happen if the cam chain skips.
Have you timed the cam correctly?
Get back to basics, pull the plugs and turn the engine over till it comes to top dead center after the intake valve opens and and closes. When it is at top dead your timing marks should be close on the alternator rotor and your points should just be opening for that cylinder.
Some of your many photos look like you have the valves on overlap where one valve at least will be tight.
Go easy on this, valves can be bent turning the engine over with a wrench and those ears on the camshaft can be broken off........don;t ask me how I know.
 
#20 · (Edited)
Choose any intake and watch the rocker arm push the valve down. When the intake starts to come up, go to the marks and line up the rotor mark to the stator mark.

For the valve to start coming back up, it will show who is coming up at the mark, meaning, you should see the T mark show who is going to match the valve you watched. So say you looked at the LT, then LT is going to lineup at the marks.

Now both cam lobes will be showing down, like an upside down V, the 'toes' of the lobes will be facing down. Facing up, you are 180° out. Toes are the tips of the lobe, or the valve is open at its peak is the toe. The heel of the cam is where you place the feeler gauge and move the adjuster with the hash mark pointing out as shown in the manual's photo.

Where are you at; position wise? Secret is watch the intake go down, when it comes up, it is at TDC-C (top dead center-Compression stroke.
 
#21 ·
Also be sure to check down the spark plug hole to see if the piston is on the right stroke to match your valves and timing marks. Piston should be at the top of it's stroke when both valves are closed and the rotor LT or T mark is aligned and the points are close to just opening; Believe me the timing can be off in a variety of ways.
 
#22 · (Edited)
Yes, I thought the valve working clearance was measured/adjusted to, via the purpose made threaded round holes that have alloy caps, 4 of them ?

Measurement between rocker arm outer "tip" and valve stem "top" .

When they are set, post a picture of the rocker arm tips, all four of them, and to be sure, the adjusting shaft "hash"/ "dash" marks.....on the outer end of the eccentric adjusting shafts.

Mark the dashes with a black marker so they are clear and easy to see.

Dd23🎅