4y weber adm34 rejetting question

**linkstar69** · 28-09-2009, 03:30 PM

I've just installed a stock 4Y into my YN85 Hilux, as the old carb was shot so I've decided to experiment with the Weber ADM34 off a old falcon.

I've thrown a rebuild kit through the carb.

I made a new exhaust and installed an O2 sensor a gauge so I can tell you the car is running very rich at the moment, just wondering if anyone would have suggestions on what jet sizes would work better with this setup.

I know that the carb is big but having watched the mixtures I feel I can get to where I need to be with re-jetting.

Any help would be much appreciated.

Link

**crowncustom** · 29-09-2009, 08:27 PM

If the carb has not been tampered in the jets since it came off the Coon then it will be running 1.40mm jets in the main and 2.10mm in the secondary.The air correction jets should also be 1.75mm main and 1.80mm secondary.
Just jet it back.1.30mm to 1.40mm should be fine but for the secondary try running a 1.40mm or 1.45mm.Plus the air correction jets could also be to large also.
Cheers Brett.

**linkstar69** · 30-09-2009, 07:07 AM

thanks brett, thats just what I needed to get started.
Link

**ozywagon** · 02-01-2010, 05:05 PM

how did you go with this?
cheers
joel

**linkstar69** · 03-01-2010, 09:09 AM

The re-jetting helped a lot but the car still wasn't maintaining reasonable mixtures accross the rev range so I ended up sending the carb away for modifications by a company up on the sunshine coast.

The car now runs and is ok but my 4y also needs a freshen up so the plan is to pull the engine down this year and bump up the comp and put a cam in it. I hoping that I will then see some of the potential of the carb after that.

**ozywagon** · 03-01-2010, 03:57 PM

thanks mate, what did it cost to get then to mod it and what did they do?

any pictures?

cheers
joel

**linkstar69** · 07-01-2010, 09:36 PM

Originally Posted by ozywagon

thanks mate, what did it cost to get then to mod it and what did they do?

any pictures?

cheers
joel

Hey Joel I'll try and get some pics for ya. It cost bout $300, more than what I wanted to pay when I started the experiment but given the car went from un-driveable to running I'm happy to be able to start trying to improve things.
According to what I can see and what they said the blocked off some things and reworked some other aspects of the carb as well as completely cleaning and refinishing it. I have to say it looks great (I know thats not important but I was impressed with what they sent back to me compared to the condition of the carb I sent them)

Are you tinkering with a 4y or just something similar? As I'd like to throw some ideas around to squeeze some more poke from my little mill when I rebuild it.

**ozywagon** · 08-01-2010, 06:33 PM

yeah i have a 3y in a 86 hilux, i bought a set of extractors and it came with a inlet manifold and std carby + i have a 34adm off a falcon. just want to get alittle more horses out of it. i'v been told the electronic ignition would bump the power up abit.

**linkstar69** · 12-01-2010, 08:18 AM

Yeah I'm looking into a few upgrades at the moment. My engine needs a freshen up so I'm considering doing a bit of home porting, having the head shaved to bump the compression up and also installing an after market cam. Of course better ignition would also be part of the picture.
I know these aren't an engine that makes huge power but the ute isn't a heavy car either.