too rich ZS

[Chicago]

Well have a nice headache right now from the clouds of blue smoke first start of the new year.
Had my ZS carbs rebuilt after a year of chronic lean condition thought they were getting leaky.
Now complete opposite problem. can't get em leaned out. Have them turned 2 complete turns CC still too rich. Sooty plugs and very rich exhaust.
Bugger... 70 TR6
Suggestions most welcome. need an asperin right now.

 

[VitSport6]

Hi.
I have just rebuilt my ZS, Im having the same prob?, I would be interested to know what might be happening, Mine are from a GT6 Mk3, CDSE as im told. But are on a Sports 6.
Thanks, Good luck Chicago.
Brian

 

[TypeRboy]

Start by dropping your float level down a bit. Is your main jet needle centered in the main jet? Is there oil in your dampers? Thicken it up to slow down the slider a bit.

Ask the guy's who rebuilt the carb if they modified or ' repaired ' the main jets at all. Some people will still solder them up and re-drill them in an attempt to renew jets worn by an offset jet needle. That almost never works out.

Of all this I would say the float level drop has the best chance of helping.. If it's too high then too much fuel will be sucked up the main jet at any given throttle position..hence rich..

Good luck

 

[78Z]

no idea but I just got this book so I could lookup anything you might need.

 

[VitSport6]

Hi.
Thanks for the info , I have the ZS maunual, along with a Vit guide for the car, I will give it a shot on adjusting the needle, float.
Thanks

 

[Chicago]

Before I pull em off to play with float level.
Want to make sure I've tried all the "simple stuff"
If I have it right, basic adjustments to start off with are low idle screw, needle height adjustment full CC for most lean, bypass valve full CC to seat, and trim screw again full CC for max lean position. There is one other spring loaded screw that I'm not sure what it does?
Anyway think I've tried all exterior tinkering still too rich, guess I'll try the float adjustment now. when it gets warmer again : )

 

[hkzimmer]

I rebuilt my ZS carbs and had the same problem, too rich. The car smelled of gas with the top up, sooty plugs, etc. Nothing I did worked until I adjusted the float level. Very simple to do, if your careful you may not have to replace the gasket if its still fairly new. Unfortunately, the carbs heve to come off the car for this procedure, but if you previously rebuilt them, then you know how to do this already. To help me I used a micrometer from Harbor Freight Tools (cheap stuff but for this job, well worth the $6) to measure the 16mm clearance.

 

[Chicago]

Thanks for all the excellent advice.
Dropped the floats to 17mm from about 15.
seems to have helped rear carb lightened up rear
plugs 4-6. Front still sooty, too cold out now.
found out the remaining spring loaded screw left side is summer winter adjust, didn't know that before. Will try some more tinkering when warms up a little.

 

[Chicago]

OK, well very nice day to tinker. So lowered floats to 17mm rear carb better, front still too rich. Pulled again changed out jet seems to be better behaved maybe bad jet? Still working it out but done for today. Also installed pertronix EI one of the easiest mods I've done. Recommend to those who may be thinking about it.