Keep Dellorto DRLA 45s and Bosch 009? Options

[98101]

I suddenly find myself owning 1970 4-cylinder 2.4 with Web hot street Cam idles nicely and pulls hard at WOT. Part throttle response is not great, often with carbs coughing and even backfiring on trailing throttle. My use is mostly street, so I'd like to get this part throttle stuff sorted.

Here's pictures of the stuff that's in there now. I guess that's the infamous Bosch 009 with no vacuum advance and a PerTronix 1847A. The carbs are Dellorto DRLA 45s with short velocity stacks and these tall foam things that don't seal against the air cleaner housings. I'm willing to learn about the carbs but I don't have much confidence in the 009 for running nicely on the street. Please correct me if I'm wrong about any of this stuff.

Also from other threads I gather that switching to EFI such as MicroSquirt would cost $5K or so ... though I'm not ruling this out completely. Correct me if I'm wrong about that.






Is this kind of linkage OK?


Here's the idle you may have seen in another post:

https://www.youtube.com/watch?v=-AC53RRrXOU


Any help you can provide is appreciated!

--Michael in Seattle

[MarkV]

I does sound like it running on three cylinders. I would clean the idle jets. Those brass tubes that are sticking up with the slot head next to the carb throats are the idle jet holders. You unscrew them and pull the jet off the end of the holder and spray carb cleaner through them. You can hod the jet up to the light to see if it the orifice is clear. They are small so be careful not to lose one or drop it down the carb throat. I usually do it one at a time.

As for the angle of the linkage the actuator arm has a set screw that tightens into the hex bar. You can move the actuator from left to right so that they both have the same angle and are parallel. The swivel rod is also adjustable so that they both have the same slack. You want to make sure one of them isn't opening faster than the other.

The linkage is not metric. It set nut takes a 3/8" wrench but I use a small crescent wrench so that I can adjust it small enough to adjust the rod.

If you look at my photo you can see that my actuator arms are all the way at the end of the hex bar. Yours look like they are more inboard which doesn't really mater as long as they are both the same.

[98101]

If you look at my photo you can see that my actuator arms are all the way at the end of the hex bar. Yours look like they are more inboard which doesn't really mater as long as they are both the same.

Yes, mine are definitely further inboard ... but different distances for some reason. I'll try to buy Allen wrench to readjust and carb cleaner to clean the jets tomorrow.