50cc GY6 1400 Miles. Valve; Tips? By hitshane (Read 535 times)

[hitshane]

Hi,

    Recently I opened up my valve cover to adjust my valves. They were set at .005" Inches, both -In and Out-. The scooter went very fast at this initial setting (45-48MPH+ flat road), for its first 1200 miles, but lacked acceleration .

    I tried to tighten them at .003" in and .003" out, but it ended up being .0035" and .0045"+... It had better acceleration and the speed was there, but the exhaust valve was tapping very loud and the exhaust pipe was not loose.

    So, today I went back in at about 9:30am and readjusted them to .003" In and .003" Out. The .003" feeler was tight and the 4 wouldn't fit either lash in its dreams. I let it warm up and took it for a ride switching in between racing hot and cruising.

    

    The acceleration feels exactly like it did before I touched the valves originally , but it only wants to go 37-40MPH unless I have a slight downhill grade in the road. I have since adjusted my carb mix screw and everything else is sound on the bike.

    I want to find a good spot of that acceleration from MY* first setting and retain some of the top end from the Initial* Setting...

    

    -Should I put the Exhaust Valve out to a Tight .004" setting..? And, leave the .003" Intake?

    -Should I make them both a tight .004"

        

    -Should I set both valves to .005" like they were SET when I bought the scooter new?

    

    *I think the exhaust valve tapping was louder on my initial setting, because the Intake was at a different pace and the two didn't drown themselves out as much...

    

    **Any input would be awesome from some people who change their valve lash adjustments a lot on 50-60cc engines. Mine happens to be a 60cc 2013 TaoTao.

[Alleyoop]

Got to say your doing something wrong, You said they were originally both set at .005.
Then you set them to .0035 and .0045 and they were noisy??? NOT POSSIBLE BRO that is a tighter gap than the .005 setting, so the .005 setting would have clattered even more.
Alleyoop

[adamhoyer]

Did you let the engine cool down?

[hitshane]

Yes the engine was cooled down.

I think it was louder after I set them because they weren't popping open and shut at the same time anymore, because they weren't the same setting. They weren't tic/tic, tic/tic, tic/tic; they were -/tic -/tic -/tic. One was open/close longer, and the other popped open/shut faster... Then should I put them both at .004"? Because .003" for both I lost performance...

**I am thinking the quick open/close pop of loose valves, provide better compression and have more torque than the flowing open/close motion of the tight tolerances on the cam lobe. This is proven with not only Honda but on many engines with solid cam/over head valves and/or solid lifter Camshafts, that less gap = more HP, more gap = more Torque.

***

-Should I put the Exhaust Valve out to a Tight .004" setting..? And, leave the .003" Intake? 

-Should I make them both a tight .004" 

-Should I set both valves to .005" like they were SET when I bought the scooter new?

****Yes I am splitting hairs over a thousandths of an inch, but they sure do matter don't they

-Shane

[hitshane]

.

[hitshane]

Jul 17, 2014 13:42:05 GMT -6 Alleyoop said:

Got to say your doing something wrong, You said they were originally both set at .005.
Then you set them to .0035 and .0045 and they were noisy??? NOT POSSIBLE BRO that is a tighter gap than the .005 setting, so the .005 setting would have clattered even more.
Alleyoop

Alleyoop,


      I do want to say that my scooter is running great now and I did leave my valves set at .003" In and Out. It had never been set this tight and after a couple hundred miles it settled in nicely. Thank you for the direction.


-Shane

[Alleyoop]

TICKY TICKY TICKY is good, that tells you they are not tight and not to loose. CLATTER CLATTER CLATTER is to loose. Remember a little loose valve is a happy valve.

[Bashan]

Just to clarify, .004" is loose for a 50 and .003" or .002" is a tighter setting. Also, the gap is not the duration. That is determined by the "profile" of the cam lobe. The wider the lobe the longer the duration. The gap has nothing to do with the valve "popping" open or closed. It is simply the gap between the rocker arm and the valve stem. If the valves are set too tight, meaning a very narrow gap such as .002", they will hang open when the bike is hot and you will get poor compression. If they are wide enough, they will "buzz" just a little and that will mean they are seating and providing good compression. However, I'm glad you're running to your satisfaction and hope it stays that way. Too loose is better than too tight with valves. Here's the spectrum... very tight: .002".......to....very loose: .006" By the way folks, don't go past 1000 miles on a valve set. Actually every 500 is not a bad idea. It takes 15 minutes.