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

[98101]

The next morning I limped the car (with frequent bangs from the carbs and sometimes the exhaust) to a VW shop that had been recommended by a 914World member. When I showed the owner the picture of the mismatched throats he expressed his opinion the carburetor was damaged, possibly by a backfire. He also didn't think the mismatch was bad enough to explain how awfully my car was running.

We spent a couple hours fiddling with the tuning. We noticed that all four air bypass screws were open. Closing them had no effect though. Re-open the vacuum ports... no effect. Inspected all the jets. Checked the jet sizes -- they were the original ones that come with the carb. We even tried changing back to the Bosch 009 distributor. No effect. Tamper with the CSP linkage.... no effect. The engine would idle (with soft pops every few seconds), but wouldn't run at 2000RPM. At open throttle it would run faster than 2000RPM though. At higher throttle settings I noticed gasoline splashing and sputtering from the left carburetor -- the leaky one that's generally covered by muck, not the one with the mismatched airflow.

The shop owner admitted that he was stumped. I thought that he would want to open up the carburetors to see what was happening inside, but I guess he sends them to another shop for that.

He did have *another* pair of DRLA 45s, new old stock. We installed those, made a few adjustments, and the engine idled more smoothly than I had ever heard it. At this point we had worked through lunchtime into the afternoon. Once I heard that new-car idle, I had zero desire to put my old scratched, dented, leaky carburetors back on. He called his contact at CB Performance for pricing advice, and suggested he'd sell them for $750. (No, he didn't have any new Webers lying around.) It took me about half a second to decide: YES.

I'm pretty sure y'all will give me some flak for this decision. I'm 80% sure my leaky left carb and my bent right carb could have been fixed, slowly by me, or quickly by a carburetor shop. But I really feel I'm done with those old carbs. The previous owner was using those foam air filters, letting everything in around the edges. He'd left two vacuum ports and four bypass screws open. He had them mounted on deformed gaskets. In one case there was a paper gasket stuck on top of the squishy one. In my care they'd experienced at least a thousand explosions. Who knows what hell these carburetors have been through in their life?

(However, my carb problems weren't over yet! Continued next post ....)