Crank has difficulty turning after rebuild

[KylesXs]

Reassembled the top end with the Xsperformance big bore kit however when I went to turn over the bike with the spark plugs out, kicker wouldn’t budge but was able to turn the crank with a lot of force. Took off the rocker box to be 100% sure the cam was properly aligned. When I backed off the rocker arms, that seemed to help it turn over a lot easier. I noticed it particularly gets “stuck” during the intake stroke when the rockers are pushing the intake valves open.

Made sure the cam chain was not too tight and the pistons seemed to move fine with given gaps and cylinders.

It is impossible to turn over with the spark plugs in.

Thoughts?

- Kyle

 

[KylesXs]

I am now able to kick it over easier after doing so a couple dozen times, maybe needed a little more oil flow to get it going. Still impossibly hard to get it turned with the spark plugs in…

 

[KylesXs]

Seems to be excess pressure building in the crank cases, which would make sense due to where I’m having trouble in the stroke. Made sure oil baffle was in when installed and breather assem. Just speculating…

 

[toglhot]

Easier to turn over when the rockers are backed off, and getting 'stuck' when the intake valves are opening??? Sounds like the valves are contacting the piston. Before you do anything shine a torch through the plug hole and check.

 

[KylesXs]

Welp… sometimes you solve your own problems. The retainers on the valves were installed upside down causing the springs to be preloaded in such a way that did not allow for a whole lot of movement when opening the valves. Time to tear it back apart

 

[Its been a long time]

Welp… sometimes you solve your own problems. The retainers on the valves were installed upside down causing the springs to be preloaded in such a way that did not allow for a whole lot of movement when opening the valves. Time to tear it back apart

Good find and excellent learning.

 

[toglhot]

How the devil did you install,the retainers upside down?

 

[KylesXs]

After comparing pictures, as you can see my valve extends past the retaining clip. They are supposed to be flush with the top. Don’t know how I managed to do this. Time to check the valves and springs for damage.

 

[KylesXs]

View attachment 261459After comparing pictures, as you can see my valve extends past the retaining clip. They are supposed to be flush with the top. Don’t know how I managed to do this. Time to check the valves and springs for damage.

Peep broken stud lol

 

[gggGary]

yeah the collets aren't seated in the valve stem groove, all the way in?

There are early and late design collets/valve stem grooves.

 

[KylesXs]

yeah the collets aren't seated in the valve stem groove, all the way in?
View attachment 261461

There are early and late design collets/valve stem grooves.

They collets are in the grooves, my theory is that since they are tapered, I just put them in upside down and the retainer is now resting on the bottom of the collets instead of hugging the sides. I’m surprised it has exploded yet.

 

[toglhot]

You're kidding, I think I'd hang up my spanners if I was you.

 

[Wingedwheel]

Glad you found that before they popped out and you dropped a valve. No harm, no foul and we all learned something.

 

[Jim]

Every place I worked where we did engine work, it was required we smack the valve after install.
You block the head up so the valve doesn't hit anything, lay a rag across the spring, set a piece of wood on that, then use a hammer to smack the valve several times. Hard enough so you pop the valve open (that's pretty hard). If a keeper isn't seated correctly, it'll come flying out.... which is why you place the rag over it... to catch it.

Reason being, if a keeper is gonna pop out, better it does it on the bench and not when you get the engine installed and running. Make that a habit. Had you done that in this case, your mistake would have become apparent in short order.

 

[AUTOMAN]

Whacking em after install is mandatory.
Makes for a lovely 2 note song. Ping/pong.

Or crap rap music like ping, pong ping fart ping pong fart fart.

cliff

 

[Wingedwheel]

plus 2 on the whack-a-mole.

 

[KylesXs]

Thanks for the advice glad I didn’t learn the hard way yet!

 

[JJames]

You're kidding, I think I'd hang up my spanners if I was you.

Naw, don't do that. There would be precious few of us here is we gave up after a stupid mistake (or ten. Lol). Stick with it and ask questions when you need to. You'll find that there's not much you Can't accomplish.

 

[bosco659]

Naw, don't do that. There would be precious few of us here is we gave up after a stupid mistake (or ten. Lol). Stick with it and ask questions when you need to. You'll find that there's not much you Can't accomplish.

Agreed, carry on with your project. I’ve done many things I shouldn’t have over the years and that’s how you learn. Pay no mind to the non constructive comments from the ’s.. lol

 

[KylesXs]

Naw, don't do that. There would be precious few of us here is we gave up after a stupid mistake (or ten. Lol). Stick with it and ask questions when you need to. You'll find that there's not much you Can't accomplish.

Agreed, carry on with your project. I’ve done many things I shouldn’t have over the years and that’s how you learn. Pay no mind to the non constructive comments from the ’s.. lol

Thanks guys my mistakes don’t phase me any more. Lots more learning to come.