Jump to content

wobblenorbed

2016 4t not starting after valve clearance adjustment

Recommended Posts

I’m often told when riding trials that my 2016 4t is really quite. However, I have always thought that it was a bit “tappety”. 
Anyhow I decided that if I can’t ride it at the moment I might as well check the clearances on the valves. 
So I ran the bike yesterday and left it overnight to cool right off. 
Today I stripped the bike down and took the valve covers off to check the clearances and found that the tappers were really tight! So much so that it took a full turn and a half on the adjustment screw to get the feeler gauges in. 
Any how I went ahead and adjusted to the correct gap and rebuilt the bike. Now the bike won’t start and is really hard to kick over. In fact it’s like trying to kick a 1990’s Honda cr500 over. 
What have I done wrong? 
Any help will be great thanks. 

Edited by wobblenorbed
Spelling mistake

Share this post


Link to post
Share on other sites
 

It sounds like you have adjusted the valves when they weren’t closed so as a result the valves are now not opening correctly. I don’t know the correct procedure but somebody on here will.

  • Thanks 1

Share this post


Link to post
Share on other sites
 

Hi

It's quite a squeeze to get to the valve adjusters and get a good measurement with a feeler gauge, did you drop the engine forward to gain access?

There is a bolt at the front of the engine that engages with a recess in the crank at TDC.  Did you use this to get to TDC to set the tappets?

I agree rechecking may well resolve the matter.  In addition the engine has an automatic decompresser that works on the valves.  Has this been disturbed inadvertently?

Stuart

 

  • Thanks 1

Share this post


Link to post
Share on other sites
 
 

Did you set them while on top dead centre ensuring it was on the compression stroke.. must be on compression stroke

  • Thanks 1

Share this post


Link to post
Share on other sites
 

How do I know if it’s on the compression stroke? 
Also how do I check if I have disturbed the decompression valve? 

Edited by wobblenorbed
Missing details

Share this post


Link to post
Share on other sites
 

Have a look at the manual for the decompresser details.  (It works by keeping one of the valves open until the engine fires)

It has a fine spring that holds it in the correct position for starting.

TDC on the compression stroke has both valves fully closed and, consequently, there is a gap in the tappets.

TDC on the exhaust stroke has the exhaust valves open (depressed).  You should be able to see the valves opening and closing as you rotate the crank.  Use the flywheel nut to turn the engine.  Make sure you turn it in the correct direction to bring it up to TDC.

  • Thanks 1

Share this post


Link to post
Share on other sites
 
2 minutes ago, stu109 said:

Have a look at the manual for the decompresser details.  (It works by keeping one of the valves open until the engine fires)

It has a fine spring that holds it in the correct position for starting.

TDC on the compression stroke has both valves fully closed and, consequently, there is a gap in the tappets.

TDC on the exhaust stroke has the exhaust valves open (depressed).  You should be able to see the valves opening and closing as you rotate the crank.  Use the flywheel nut to turn the engine.  Make sure you turn it in the correct direction to bring it up to TDC.

Thank you for this. 
I will apply everyone’s advice and report back tomorrow 

Share this post


Link to post
Share on other sites
 

Piston rises to top of stroke on compression and exhaust stroke, with spark plug out you can feel the slight pressure on compression by putting thumb over the hole, then align the marks when you know it’s the compression stroke. haven’t adjusted mine so I’m not sure of the timing marks used on beta flywheel. Some decent videos on YouTube of how to do it . Has to be compression as that’s when the intake and exhaust valves are shut. 

  • Thanks 1

Share this post


Link to post
Share on other sites
 

Also don’t tighten the gap so it nips the feeler gauge, just touching so it will slide in/out ok, Too small as gap is as bad or worse 

  • Thanks 1

Share this post


Link to post
Share on other sites
 
 

Okay, thank you all for your replies. 
I followed Timdog’s instructions and I am happy to report that the bike now starts no bother and is running great. 
However, I am still not happy with the tappety noise coming from the top end. 
I would much prefer the engine to run much quieter. 
Any advice on what to look for next now that I know the valves are adjusted correctly? 

Share this post


Link to post
Share on other sites
 

If the issue is just when the bike is cold, you   could go to an oil with a lower first number possibly a    5W50   or if where you live it never gets very hot perhaps a 5w40

Share this post


Link to post
Share on other sites
 
 

Can you post a video so we can here it?  May just be the usual sound of a 4 stoke.  Other people are commenting on the bike's quietness so seems unlikely there is anything particularly unusual about the "tappety noise".

Could just check that the cam chain tensioner is correctly adjusted.

Share this post


Link to post
Share on other sites
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...