Hi

I have a old 13b from a RX-4 -78 with Racing Beat carb/header kit.

My problem is that it only runs on one rotor the rear one. I have checked the compression, F=120psi R=90psi and I have sparks on all of the plugs!

Can anyone guide me to the problem?

Fredrik

 

your loss of compression could be due to carbon build up on the rotor. I have taken a bunch of them apart and found that many times the side seals have excessive carbon build up and don't seal as well as they should

 

A movie of it running

http://www.youtube.com/watch?v=zZ2PQi8u7Yc

Fredrik

 

My Rx4 sounded like that when i brought it home. I pulled the top off the carb only to find the rear needle ans seat for the float had came loose and was unscrewing thus cutting fuel flow to the rear rotor.
Check the fuel levels through windows in the float bowls
I would have a look down the carb when the engine is running and see if fuel is flowing through emusion tubes when you accelerate and at idle.
I hope that gives u a start

J

 

Also try a fresh set of spark plugs, I have had issues with old bad plugs

 

hey i have a question, why do u have a piece of vac tubing connection the barb in the primary bowl that the omp line would go to, to the port on the metering plate for the vac advanced? that should be capped off if ur not using it for vac advanced. seems to rev ok to be running on one rotor. engines that i've had run on one rotor were slow to rev up, and barely will idle.

 

I like the motor jig setup, thats pretty sweet...

 

When my car was running on 1 rotor, it idled fine. I drove it to and from work for 4 months before I replaced it. It couldn't get over 35, but it never died on me.

I'm going to agree with la23srx4. Check the levels in the floats. If its not that, might want to take a look at the dizzy.

 

OK, thank´s for all the tips. I will try some of them when I go test it again.

Do anyone have a good picture or a manual on how the carb should be conneted?

Fredrik

 

OK now I have been and tried the engine out again, the front rotor wont start easy but if I push the throttle WOT it starts and after some adjustments to the idle premix it almost idled.

Have anyone any ideas of what could be wrong?


Fredrik

 

Hi there again

O.K.
In order to go through a process of elemination i need you to answer the questions i asked previously.
#1 Is there fuel coming out the emultion tubes at idle on the dead rotor?
#2 If the answer is no, pull the top off the carb and check the float levels? If it is and fuel is flowing at idle we will look elsewere.

There are 2 fuel circuts ,Idle and Acelleration

If your not sure,pull the air cleaner off and take a video running down the carb ideling and acelerating......lots of light and we will see if we can`t figure this out for ya.

I will try to help u further but we need to start there.

Cheers Jason

 

Check for a sticky or stuck apex seal. My 13B sounded like that when I first started it. I went thru the carb drill, (floats, jets, e-tube etc.) then the dizzy drill, (pick-ups, advancement, caps, rotor etc.) Nothing! Come to find out I had a sticky apex seal. I removed the lead plugs and sprayed each seal with carb cleaner and moved them in and out with and unsharped pencil until they were springy. I then hit them all agian with marvel oil and let it sit for a day. I turned it over a few times to clean all the crap I sprayed in there and then cleaned the plugs and it fired right up and now runs great. I love that test stand set-up, top shelf stuff right there. Good luck!