Valve Lash Settings By Hammerspur (Read 3,555 times)

[Hammerspur]

The E-Ton service manual for my Beamer R4 150 lists a recommended valve lash setting of 0.07mm (0.0027").

Strikes me as kinda' tight from the reading here and elsewhere most references are for 0.004-0.005" (0.101 - 0.127").

I've also seen the 'corroborative' reference to 0.002 - 0.003" (0.0508 - 0.076mm) here:
scooterdoc.proboards.com/index.cgi?board=engine&action=display&thread=140

So I know loose valve tolerances will make a lot of clattering noise, but if things are too tight what symptoms would one look (listen?) for?

Also, here's a time saving quick conversion table I found for anyone who could use it:

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Conversions SAE to Metric:

inch - mm
.002 - .051
.003 - .076
.004 - .102
.005 - .127
.006 - .152
.008 - .203
.011 - .279
.012 - .305
.013 - .330
.014 - .356
.016 - .406
.018 - .457
.020 - .508
.022 - .559
.025 - .635

[sprocket]

>>So I know loose valve tolerances will make a lot of clattering noise, but if things are too tight what symptoms would one look (listen?) for?

Well you know they are too tight when the piston slaps a valve...

The rocker arm breaks...

The cam gets worn...


These are interference engines... like the old VWs. And when they interfere it cost big bucks...valves, head etc...

I did mine today, and they don't chatter...they 'tick' like a fine Swiss watch...

Use .004 INCH and .005 INCH... the community agrees...

[Cruiser]

Symptoms of tight valves are hard starting and power loss and possible back firing through the carb.

A broken cam chain while the engine is running can cause the engine to grenade due to valves hitting the piston on interference type engines. A broken valve or valve keeper while the engine is running will grenade all engines interference or non interference (free wheeling).

Tight valves will not hit the piston, a broken rocker arm will cause the valve to stay closed which will not hit the piston, and a worn cam will not open the valves as much as a new one which again will not hit the piston.

The main thing to prevent an interference type problem is a healthy cam chain.

[sprocket]

>>>Tight valves will not hit the piston

Sorry...

Bent valves are common on the GY6 and the only cause is... no valve gap...

[Cruiser]

Are you sure you are not confusing this with valve float? This is common when the engine is over reved and the valve springs cannot shut the valves fast enough to keep them from contacting the pistons. Still has nothing to do with tight valves. If the valves could be adjusted tight enough to hit the pistons, the engine would not run to start with because there would be no compression.