I adjusted the valves to the specs. the manual said and also your forum. My milage has gotten worse and I was wondering what would cause this. Also the ones that needed adjusting were to loose which I assume is due to wear. If I was to make a mistake would it be better to be to loose or to tight as I've checked it twice since and all are correct. Also wanted to know if a adjustment to the timing or carb is necessary after doing this. The manual does'nt say it is. Is a 22R engine, thanks

 

Whenever I adjust the valves, I always check timing and idle... You're gonna be in there anyway, might as well. Hope that helps.

 

Check ur o2 sensor mVs should be from 200mV-800mV and/or going at least to 450mV engine at operation temp if not sensor is bad and u will be in open loop running rich also make sure vac advance on distributor is opertaing correctly

 

its better to be loose then tight. Tight you can burn up a valve, loose you will just loose effiency. (sp )

anyhow when you did you adjustments did you do them when the motor was warm or cold? you are supposed to do it hot, like drive it on the freeway then quickly pull it in and start ripping on it. If you are having a severe mileage drop right after your adjustment i would say its your adjustment thats off...

 

As metal heats it expands so he ^ is right it sucks since its hot Id do that first if still bad time to check some sensors for correct op voltages or resistance any one not working right will send pcm into fuel enrichment mode at most times. My cts is tellin my pcm its colder engine when its not.

 

So what did you set the valve lash to? intake/exhaust I have heard many different opinions on valve lash settings. I run a 292 and set intake at 8 and exh. at 10. I also recheck it when its hot. Make sure your cam hasn't been scourged. Sounds to me like your timing might be off. Millage could be affected by many things such as tire pressure,clogged air filter,added weight(ex: a full tank of gas compared to a half full tank)I wouldn't make a huge difference but there's a difference.What sort of millage are we talking about here?

 

if you have a custom cam there should be valve specs with your cam. If not I would run them at stock spec which is:
Intake clearance: 0.20 mm (0.008 in.)
Exhaust clearance: 0.30 mm (0.012 in.)

after you set your lash if you are running a weber you might need to re-set the carb if the valves were way off and you had adjusted the carb with them like that. Also check for a vacuum leak, you might have left something unplugged