Jump to content
Email-only Log-Ins Coming in December ×

IGNORED

Stalling issue(under throttle)


NA&CH

Recommended Posts

Starting tinkering. 

Pulled the wires from the plugs and 2&3 have no change when pulled. All other drop idle significantly. Pulled all 1 at a time. Switch wire locations? I am matching up wires from cap. ?

I plan to replace the fireball system with something newer and current then maybe the 123 after I figure this out. 

Thanks again,

Chris

20180714_101433.jpg

20180714_101426.jpg

20180714_101422.jpg

Link to comment
Share on other sites

Spark plug Pictures from this past weekend. I have some tools arriving this week to do test on various items. Also something I should have done before jumping to the modification pages... the plugs are less then 2 months old. 

Any more insight is greatly appreciated. 

Chris 

20180714_151429.jpg

20180714_151426.jpg

20180714_151423.jpg

20180714_151420.jpg

20180714_151438.jpg

20180714_151432.jpg

20180714_151417.jpg

Link to comment
Share on other sites

Using the Uni-syn and the front carb has little to no air pulling when at 2k. The rear is working. It is rich but working. What would cause the front carb to not be "working" or is this normal. Also where should the distributor be set at advance wise? 

Reading how to tune Su carbs now...

Chris

20180719_165407.jpg

20180719_170857.jpg

20180719_170849.jpg

20180719_170841.jpg

20180719_165411.jpg

Link to comment
Share on other sites

 Sounds like the carbs are out of balance. Any early Z shop manual will tell you how to balance them. It's not difficult. I'd start with resetting the nozzles 2 1/2 turns down and then going thru the balance procedure. Dist. is usually set at around 10 degrees advance. There is a good thread about SU tuning. Google "Quick and dirty SU tuning.

Edited by Mark Maras
Link to comment
Share on other sites

Read the chapter in the FSM about the carbs.  Or just Google SU's.  They're not "normal", they use intake vacuum to raise a piston which then allows air flow.  What you see on the gauge is the vacuum on one side of the carb.  A higher number actually means less flow.  You might have a stuck piston.  They also use oil to damp the movement of the piston.  They're odd mechanisms!

Link to comment
Share on other sites

I believe you will need to get a front mounted airflow measurement tool, measuring from where you are is after the balance tube.

But I could be wrong, I would want someone else to double triple confirm.

Was there a filter in the engine compartment? There are two additional filters at the float chamber of the SU carb, for me it was throwing off my float measurements, and causing my stalling issues, after cleaning them out, I was able to get a good tune.


Sent from my iPhone using Classic Zcar Club mobile

Link to comment
Share on other sites

Agree with what's been said above. 

A simple test would be to raise both pistons and see if they fall at the same rate, pretty slow fall if the damper oil is right.  They should make their "clunk" sound at the same time when they hit the bottom.

You need one of these if you have dual carbs, makes things so much easier. 

https://www.amazon.com/Latest-Rage-Deluxe-Carburetor-Airflow/dp/B00CMC57R0/ref=sr_1_fkmr0_4?ie=UTF8&qid=1532074358&sr=8-4-fkmr0&keywords=unisyn+carb

617rEHiRmbL._SL1095_.jpg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   2 Members, 0 Anonymous, 227 Guests (See full list)

×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.