Intake Valve clearance issues

[dbudree]

Recently purchased a 2017 Ruckus for my son with just over 1000 kms on it.  Ran fine for a few days the all of a sudden was hard starting and lacking power.  Eventually no start at all.  Found the intake valve to have NO clearance at all.  Measured the shim and found it to be 1.16MM thick.  Smallest shim I can get from Honda is 1.20.  I carefully ground the shim down to 1.0mm, reinstalled and the bike fired right up.  It ran like this for a few hundred KMS but stalled at a light and would not restart tonight.
Again NO clearance on the intake valve.  I took another skim off the shim bringing it down to 0.82mm, reinstalled and again the bike is running great. 

Would this be a valve seat issue, (valve pounding its way into the seat) or a valve stem stretching issue?  Any help will be appreciated.

D

[Baizy]

Aug 23, 2020 23:35:57 GMT -5 dbudree said:

Recently purchased a 2017 Ruckus for my son with just over 1000 kms on it.  Ran fine for a few days the all of a sudden was hard starting and lacking power.  Eventually no start at all.  Found the intake valve to have NO clearance at all.  Measured the shim and found it to be 1.16MM thick.  Smallest shim I can get from Honda is 1.20.  I carefully ground the shim down to 1.0mm, reinstalled and the bike fired right up.  It ran like this for a few hundred KMS but stalled at a light and would not restart tonight.
Again NO clearance on the intake valve.  I took another skim off the shim bringing it down to 0.82mm, reinstalled and again the bike is running great. 

Would this be a valve seat issue, (valve pounding its way into the seat) or a valve stem stretching issue?  Any help will be appreciated.

D

Seems I may be a little late to the party here but what may be happening is that the ruck sat for a bit of time and had a bit of buildup on the valve seat and now that its being used more frequently it's worn the seal down and created a better seating surface again. If you have some money to play with you could also buy a valve shim kit for between 50 and 100 dollars. They are treated so you're likely to have the shim stay the same thickness for a while. Hope this helped you somewhat!