Spider stutters when accelerating

[meman124]

Hi Guys,

Need some help. My 1969 Spider starts and idles ok, but when accellerating, it has a flat spot in the curve en feels like it stutters.

Does anybody know what carbs these are? https://www.dropbox.com/s/0sz5pdmq13wj0 ... .44.33.jpg

https://www.dropbox.com/s/tuguv7aqydn2y ... .27.25.jpg
https://www.dropbox.com/s/qkipwy2enmlei ... .52.30.jpg

Are the carbs the culprit?
Thanks for helping.
Bart

[So Cal Mark]

dual carbs must be synchronized in order for the engine to rev smoothly

[vandor]

You have dual Weber IDF carburetors. Your problem could be low fuel pressure, carb synchronization, or ignition.
Start with fuel pressure, it should be 2-4 psi. I usually tape a fuel pressure gauge to the windshield and drive the car, so I can observe the pressure while driving.

[meman124]

ok ordered timinglight and synchrometer, waiting for it to arrive.
In the mean time i too 1 carb apart to clean it. Hope that i can put it back together so that it will work.
Are there any guides around that are any good?
Can i make a diy fuel pressure gauge from spare manometer and T?

Bart

[carl]

Could be something as simple as the accelerator pumps not working. With the engine off, look down each barrel as you work the throttle linkage. You should see gas squirt down each venturis. These pumps enrichen the circuit when you accelerate and if they are not working you will get a flat spot or stuttering when you hit the gas. Not uncommon for the pump diaphrams to get old and stiff and stop working.

carl

[meman124]

This morning, i took a screwdriver to the carbs, took them apart as far as is dared. Took 3 different copper jets(?) out. Got al the fuel out, cleaned the wells. Sprayed the lot with carbcleaner, went and had breakfast. Came back, put the airgun on the compressor and gave the lot a good blow until nothing came out of the holes anymore. Put them back together and started her up. Starting was alot easier than normal. The testdrive was great, she never ran that good and boy i did not know that that engine had that much pull...
Happy as can be! I cannot believe that i have had the spider for 7 years and never cleaned the carburators. It is alot more fun to drive now.
Waiting for the synchrometer and timing light to arrive so that i can balance the carbs and adjust the timing.

Bart