Quote:
Originally Posted by Thumper
ZS172-FMM-3A 249cc (Templar X):
This is an OHC engine, not pushrod. I set both at about 0.006" It gets hot (this blazing Summer), so I wanted to make sure the valves would close. Excessive, maybe, but I do NOT hear valve tappet noise from this head. I can probably close them up somewhat. High performance recommendations (Henner) are TIGHT (0.002"), but until I have at least 1000 miles on the engine, valves can "seat". And as I said, I don't hear valve noise from the head. Once I observe stable clearance, I will drop the spec accordingly. Keep in mind I am still under 250 miles on the bike!
The TBR7 and Storm are both pushrod CG clone (ZS167-FMM 229cc). My son's TBR7 is getting more miles now. I will begin to close the gap on these as well. Neither of them make much valve noise, and it isn't like any of these bikes are operating under rpm conditions that could cause them to float 
I am more concerned about making sure there is good oil in them and that they are not overheating. All three of them are running great! Power level is close to best possible without head mods, and they start instantly. |
The difference with the ohc engine is it has way less mass acting.on the rockers. A larger gap on an ohc motor won't make as much noise when out of spec because it has way less momentum behind it, so the impact force is lower.