My Westy lags acceleration

tzack59 · Post by **tzack59** » Fri Apr 27, 2007 10:30 pm

I've rebuilt my Westy with a 1.7L engine w/jugs bored to approx 1.8. I'm running a mechanical dizzy with a progressive carb and an electric fuel pump. I have no idea now where to set the timing on my dizzy now. ???BTDC or ???ATDC. Carb rebuild kit is done and I'm still getting lag in acceleration. Vacuum Leak? New seals on the intake manifold both at the carb and block end and still lag in acceleration. I've checked the line coming from the brake servo and it seems to be tight and I capped off the vacuum lines on the carb. Is there another place where a vacuum Leak could be coming from. I've tried every thing to fix this problem but still I have a lag in acceleration. I live in Nebraska and the weather has in the 50's, lately. So I don't think it's weather causing poor performance. I need help, suggestions, anything. I want to go to Niagra Falls this summer and my comfort level is very low right now in the condition my Westy is in.

wildthings · Post by **wildthings** » Fri Apr 27, 2007 11:11 pm

A progressive carb with an 009 dizzy is a bad match. They both typically cause hesitation off the line and weak low Rpm performance. Time you motor at full advance, around 3500 rpm, and set the timing to 28-30° BTDC. There are a lot of things that can be done to improve the progressive, but unfortunately there are probably 5 or 6 different progressive carb set ups out there and each is a little different.

Bleyseng · Post by **Bleyseng** » Sat Apr 28, 2007 9:11 am

The 009 mech dizzy has only 17 degrees of total advance.

The stock type 4 dizzy has 32-34 degrees of total advance and is mechanical with a vac advance. The vac advance works only at low rpms to give the engine more umph. Switch back to help make the single carb run better.

wildthings · Post by **wildthings** » Sat Apr 28, 2007 9:23 pm

Vacuum advance works at all rpm's. As its name implies it is vacuum dependent, not rpm dependent.

busman78 · Post by **busman78** » Sun Apr 29, 2007 9:34 am

With the 009 you want to set initial timing at 8 to 10 BTDC, then with a timing light as you accelerate you should have a total of 28/30 degrees advance by 2800 to 3000 rpm (possibly a little sooner). Do not set total advance at 3500 rpm, you will have absolute lousy off idle acceleration. Plus your at idle timing will be to high and be a candidate for detonation when you try to accelerate. Watch the timing light on the pully and scale, it should be steady and smooth, if it is bouncy then the advance plate in the distributor need cleaned and lubed or the points replaced.

Now for the progressive, with the air cleaner off, when you accelerate does the fuel squirt immediately or is there a lag, if there is a lag then the cam arm needs to be adjusted so that it is not touching the accerator arm but will engage as soon as the accerator is opened.

Your idle jets have got to be sized correctly, no more than 3 turns out with the idle adjusted or two turns from seating. Although this has nothing to do with acceration it does effect overall running.

Got a vacuum gauge? Great tool for checking a carb.

Tinkertom2k8 · Post by **Tinkertom2k8** » Thu Dec 04, 2008 5:34 pm

My 73 Westy also has the same issue, lugging off the line and it also has the 009 dizzy with a progressive two barrel. I have done the idle adjustments and am using 10 btdc on the advice of a VW mech. It still lugged.

Cold weather has pointed out that the choke plates were not moving also. Pulled the cover and put the end of the coiled element back on the choke plate crank lever. Now it stays about 1/4 closed cold or hot

but now it doesn't lug much at all! Could this be a clue that the idle jet needs to be enlarged? Also, can anyone tell me how to properly adjust the choke on this guy?

busman78 · Post by **busman78** » Thu Dec 04, 2008 6:37 pm

Idle is just that, if you have the proper lean best idle which having the choke closed part way says you don't, then the lug can be - accelerator not squirting immediately as throttle opens, most squirt jets are 55, yours may be too big, or if it is a 50 it may be to small, or air is to cold therefore fuel not properly atomizing, or 009 (which requires rpm to advance) not advancing quick enough. The more recent 009's being sold have an advance plate that has the feel of 60 grit sandpaper. Basically they come from the factory dirty, take the plate out, clean it and use a fine lube like sewing machine oil or SuperLube(teflon based oil). As I mentioned above watch the timing mark with a timing light, try it on all four wires, if it is bouncing or a couple of the wires indicate off TDC then you have a problem with the distributor.

Check the accerator, look down the throat of the carb, open the throttle, the squirt jet should shoot a stream of fuel immediately. Do this several times so you get a true indication of when the lag happens. In some rare cases I have had to advance to 12 degrees with an 009, still maintained a max a 31 degrees of total advance. I currently use a Mallory Unilite and have no lag. The SVDA distributor is another option if the lag is determined to be caused by the distributor.

wildthings · Post by **wildthings** » Fri Dec 05, 2008 8:20 am

The progressive takes about 1/2 of a second to open the power valve when you hit the gas. Until the power valve is flowing the engine will bog. My solution to progressive bog is to disable the power valve and then jet the engine to run without it. This is what many dual carb setups do to start with.

mnsKmobi · Post by **mnsKmobi** » Sun Dec 07, 2008 5:42 pm

Even at 50F (10C) you still need to get some warm air into the carb. The main thing I did to improve the driveability of my weber progressive was to adapt an air cleaner off another car to provide hot air from the stock location when the engine was cold. I used an air cleaner off an old Mazda only because it uses a wax capsule to move the flap to cut off the hot air when the engine warmed up. This meant I didn't have to locate a vacuum source.

I already had an SVDA style distributor.