engine and drivetrain misfiring race car....

[markraspi]

Hello again. This is a follow up note about my ITB 2002 race car and the odd misfire that only lasted a few laps. The culprit turned out to be the carb. It seems that the aux. venturi for the primary barrel had worked itself loose. This seems to have caused some kind of problem in that barrel probably leaning out the mixture just enough to make it misfire. I think that the intense heat more than likely closed up this loose condition after a few laps and allowed the engine to run properly.

This carb is very old and has been used in this car for over 12 years. I had discovered this loose condition once before and thought I fixed it forever. I drilled and tapped the side of the carb body and made up two small set screws to hold the venturis in place. Then I safety wired the two together. This was fine but I guess that after some use, the one venturi worked itself loose again. My assistant ( Paul Wegweiser) tightened the screw and re-wired the thing and it was good to go.

I suspect that this was going on for some time because the car ran as good or better than it has for some time.

Thanks for the suggestions......MR

[Guest Anonymous]

(nt)

[Guest Anonymous]

are these 40's or 45's?

[Guest Anonymous]

It's an old ITB car, so it'll be a 32/36DGV.

[wegweiser]

Midrange to high rpms as I recall. It's one worn-the-hell out ole Weber - but it did the job nicely this weekend! *whew!*

I got to play greasemonkey all weekend on the blue ITB car as well as the white E Prod beastie. Life = good. Bummed I missed LimeRock, though. :-(

Paul Wegweiser

[alp]

let's see some more photos of the race cars!!

[wegweiser]

Here ya' go! (sorry no "really" good uns).

3rd place finish in each car, we got lucky. :-)

The guy in the Alfa can friggin' D R I V E!

Paul Wegweiser

[bmw1602.com]

yes this was the first thing that one of the guys in my class told me to do....tap it.

[gracer]

Aux. venturie maintenence is an ongoing thing with a ITB BMW. I used to deform the ends with a hammer on an anvil to make them fit tightly. G

[danrolfe]

Mark and Paul,

Sorry I could not make it for the MARRS race, my real life has officially started so I won't see you all until next spring. I am glad to see you all had a good weekend; I saw Tim's times were better also. After MARRS 7 I pulled the carbs off and discovered a bent throttle shaft which was not allowing the butterflies to close, that is why the throttle stuck wide open coming down the straight. All the linkage was fine and even better yet did not hurt the motor. If you all are ever in the Richmond area give me a call, I would love to have you all come by the shop. Hope you have a good last race.

Dan Rolfe

EP Green 2002