Jump to content
USWE SPORTS ACTION HYDRO PACKS GIVEAWAYS!!! Read more... ×
Sign in to follow this  

Re-shimmed Valves and one intake closed up before cover was re-installed

Recommended Posts

Hey Group,

 

I just reshimmed my valves and reinstalled the cams and cam caps and when re-checking valve clearence the left side intake was still reading like it was closed tight. less the .0015! Anyways I am going to try and drop it down another 0.20 and see what happenes.

 

Anyone have any experience with this? Is this a valve job? :S

 

I also noticed on the timing that when the MCCT was engaged the intake cam would show the #3 pointing slight off center when reading, is this normal due to take up of cam chain slack?

 

Thanks.

 

-M

Share this post


Link to post
Share on other sites

Did you rotate the crank a few times by hand? That will squish out any oil under the shims.

Share this post


Link to post
Share on other sites

Mike , just make sure that the shim has located properly on the valve stem , if it hasn`t it will either keep the valve open and the piston will hit it or it will pop the collets and drop the valve , then the piston will hit it . I remember the first time I had to deal with under bucket shims back in the 70`s . I got it wrong and went the wrong direction with my calculations , you might have done the same , greg

  • Like 1

Share this post


Link to post
Share on other sites

Make sure the valve shim is properly seated, cam caps are tight, rotate engine a couple times, set TDC, check clearance, rotate engine couple turns and recheck clearance.

If it's off, adjust and repeat above....

  • Like 1

Share this post


Link to post
Share on other sites

Did all said above and the one intake is still solid tight. I've gone from a 2.80 shim to a 2.40 shim and it is the same. The rest are within spec now. What's is going in with that one valve. What's the negotiable effect of driving the bike with one intake valve acting like this? Is this a mandatory valve job?

Thank you.

Mike

Share this post


Link to post
Share on other sites

Maybe the valve retainer/keepers popped out of place… have you been running the bike between these valve adjustments?  I would start over and triple check everything mentioned.  Then put in the thinnest shim you have and measure the clearance.  Something is not right.  I would NOT run the bike as is!

  • Like 2

Share this post


Link to post
Share on other sites

I have not ran the bike in between. I just checked and rechecked and rotated back to tdc about 29 times.lol

Why not run it? It was running almost perfect except for stalling. I just buttoned it back up and was gonna put the carb on tmrw and give ride. The one thing I noticed was the bucket was sitting ever so barley above the rim. The rest of the buckets are flush. Any hints of what's goin on? Hard to fix by myself? I will try the smallest shim size next. Before buttoning it up. Any help would be much appreciated.

-M

Share this post


Link to post
Share on other sites

Maybe the valve retainer/keepers popped out of place… have you been running the bike between these valve adjustments?  I would start over and triple check everything mentioned.  Then put in the thinnest shim you have and measure the clearance.  Something is not right.  I would NOT run the bike as is!

I would not ride it , I would fully investigate this .

  • Like 1

Share this post


Link to post
Share on other sites

I have not ran the bike in between. I just checked and rechecked and rotated back to tdc about 29 times.lol

Why not run it? It was running almost perfect except for stalling. I just buttoned it back up and was gonna put the carb on tmrw and give ride. The one thing I noticed was the bucket was sitting ever so barley above the rim. The rest of the buckets are flush. Any hints of what's goin on? Hard to fix by myself? I will try the smallest shim size next. Before buttoning it up. Any help would be much appreciated.

-M

 

 

sounds like the shim isn't seated right. if it were on the top of the keeper instead of the valve, it would be ohhhh, maybe 1/16" higher ? is that what it looks like ? 

Share this post


Link to post
Share on other sites

my guess is the shims you are putting in are smaller than the depth of the pocket that they seat in.. so they aren't even contacting the bucket....if that's the case put in a shim that you can feel sticking up then start adjusting from there...if you can't get it in spec then yah....time for a valve job.

Share this post


Link to post
Share on other sites

Worst case scenario, there isn't a head on that valve anymore and only the crap on the stem (bent?) is keeping it from coming through.  Probably not the case because you said you can rotate the engine around by hand and it did run.

 

Next possibility is that valve got really burnt from continuing to ride after it started stalling so it really does need that much adjustment.

 

I have seen the spring keeper start to fail and the retainers start to sink down into it.  As mentioned that could mean the shim isn't even making contact as the keeper could be touching the bucket.  

 

Something is wrong though and you need to know what.  The closing up of the clearances is caused by the valve face starting to errode.  There is not that much thickness there to be  losing even 0.2mm. 

 

No point in trying to run the engine until you figure it out because it isn't going to run properly anyway with a valve not seating.  You will be taking it apart again in a few days and by then much more damage could result.

  • Like 1

Share this post


Link to post
Share on other sites

Thank you all for the replies.

Valve job it is.

Anyone have a good recommendation? I saw on TT the RHC is one option but I have not heard back. Another is Sisneros speed works which I was thinking of. I live in canada so it would be nice to have it domestic. What is the word from the bird.

Thx.

Share this post


Link to post
Share on other sites

I'm kinda confused… was that one intake valve just as tight before you took everything apart the first time?  I thought you re-shimmed the valves and they were good (first-time around), then you either (this is where im confused) rode the bike or rotated the engine and re-checked… now that one valve is super tight?

 

I just don't understand how it went from being good to bad from just rotating the engine… unless something popped out of place or isn't seated right.  Now if you rode the bike and it closed up quick, then yes… you need a valve job.

Share this post


Link to post
Share on other sites

Sorry for confusion. Ever since I started re shimming my valves the one intake on left side was so tight I could not fit a .0015 feeler gauge under. The rest of the valves were at spec. Even after re shimming the one intake twice it would not change. I rotated the engine plenty of times and still the same. It really felt like ground hog day. So the diagnosis is a valve job. I do not want to run it anymore and cannot figure it out. Once it's back from the valve job I will post an update.

Share this post


Link to post
Share on other sites

The one intake valve was tight from the start. I had a tickin noise coming from the engine but it worked fine except for starting and idling. The bike actually hauled ass but the starting issue and ticking noise started me on this journey.

Share this post


Link to post
Share on other sites

Which part of BC are you from?

 

Depending on your desired performance level and budget you have a few choices.  If you want the bike running as it was before the valve failed it involves draining the water, removing the head, having the seats ground at a shop, replacing the valves either with stock or stock size aftermarket, then reshimming (can be done on the bench and expect all valves to need thinner shims than before), reassemble with a new headgasket minimum (some would say base gasket too which requires pulling the jug).  Double check the clearances and put it all back together.  Head bolt torque is 43 ft/lbs (not 34 as in the book).

 

That is the basic version.  $60 head gasket, about $100 per valve, plus machining the head . That should get your head going for another 25,000km or so.  If you find anything else amiss inside .............then it costs more.  It depends on how your piston looks.  If you are paying a shop labor then it might be worth changing the piston as well but then things can get expensive.

 

If large budget and desire intervene it could involve a big bore kit, oversize valves, head work, bigger carb, different exhaust yada yada.

 

What are you running for an air cleaner?  If it is foam, what kind of oil do you use on it?  Dust eats valves.  Then it has the rings for dessert.

 

A valve cools when it sits against the seat so once the clearance is down to zero it doesn't sit and it doesn't cool properly.  Some heat does go up the stem but that is a long way.  When it stays hot it erodes even faster so riding once it starts stalling will cost a valve job although it is probably already needed.  If the clearance is actually zero you should notice that when you put the cam in it won't sit down all the way in the journal until you push it down with the cap because it is always pushing on the bucket even on the part of the cam that should not touch.  Is the cam polished all the way around from contact?  There should be a gap on the side opposite the lobe.  Put the bucket on without a shim and see if the cam touches when you set it in place.  Don't bolt it down and rotate it like this.

 

A decent machine shop used to powersports work should be able to handle the seat cutting.  It explains the seat cutting in the service manual but if you don't have it basically they machine 3 angles onto the seat and make sure the middle one is the right width.  The valves and seat cutting are precision enough that they seal without lapping the valves.  Lapping hard faced valves should not be done ever.

Share this post


Link to post
Share on other sites

Sorry for confusion. Ever since I started re shimming my valves the one intake on left side was so tight I could not fit a .0015 feeler gauge under. The rest of the valves were at spec. Even after re shimming the one intake twice it would not change. I rotated the engine plenty of times and still the same. It really felt like ground hog day. So the diagnosis is a valve job. I do not want to run it anymore and cannot figure it out. Once it's back from the valve job I will post an update.

How many times have you had to Re Shim ?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×