18R-G Missing under load

[ian]

The Angry 18R-G is having some issues, Generally idles fine, and cruises fine, but crack the throttle and it starts missing on 1 or 2 cylinders.

This started rather quickly, I am pointing the finger partially at the Webers, but before i send it to get tuned I want to rule out other causes.

I have changed the plugs, checked the rotor cap and rotor (has electronic ignition) could be the coil, but I don't know how to test this. Fuel appears to be fine at the filter, leads are in good condition.

Its really not drivable ATM and I'd like to sort this so I can get to work next week.

Cheers
Simon

hi are
you still using the ballast resistor , as that is the same symptoms as mine had
ian

[Steve M]

Just to clear my mind, was it running fine before and then this problem started up from nowhere, is that correct?

[crostek]

I
I noted also there appears to be fuel leaking (recent) from the top of the carbs from the wing nuts that are on the top of the bowl.

Cheers
Simon

The wing nut needs to be a good seal as the top of the carb is used as part of the vacuum/pressure to mix the fuel/air.

Have you check the fuel floats in the carbs are ok? or the needle and seat are not leaking.
are you running a fuel pressure regulator that don't like much more than 7 psi, I had this problem with mine but it was flooding the motor, is your exhaust pipe black or light grey after you drive down the freeway?

Have you had the pump stroke for the accel pump checked, it may be not putting enough or too much fuel in the throat as it opens up

[jeffro ra28]

Had exact problem with solex's. Turned out to be lose jets. Not sure about webbers but try removing the jet cover and make sure the jets are tight.

P.S. Race motors are driven on the street alot! Just needs to be tuned properly. They only real thing its going to hurt is your bores. And that would only be caused from ill tune up.

[pauljones1976]

Jeffro RA28 I have to agree with you. My money would be on the carbs. I had solex's do the same to me on my old RA28. Presents exactly the same. I used to remove my jets, clean them, then re-install for some relief. I never did find out exactly why they were troublesome, I know they were too big (48's) but I was running 10.9:1 static with big TRD cams. I suspect it was the seating of the jets but I'm no expert. The reason I didn't find out is because I sold the engine and bought a 3TGTE.

[river]

Hi,

Yep, get the carbs checked. Same as the previous post, my Solex caused identical problems at higher revs and under load.

Krank Franky Kleinig rebuilt and retuned them and it was like having a new engine. That man is a master and an artisan of these old carbies. Which reminds me, now that he is back in business I will have to arrange for him to give the carbs/engine a retune.

seeyuzz
river