different carb for 4ac

bina · Post by **bina** » Tue Dec 14, 2004 7:06 pm

About 2 years ago I replaced the 3ac engine with a 4ac. The job was quiet easy and straight forward. However, I tried using the carb that was on the 4ac, but couldn't get it to run properly so I put the original carb back on. It has the same minor problems as it had on the smaller engine eg; slightly rough idling and a little jerky at certain speeds and poor fuel economy around town. Probably the biggest problem is that is starts quite hard when it is hot and smells of gas. Should I find a different carb from a 4ac engine or would rebuilding or rejetting the original carb help. Is there a particular aftermarket carb that works well for this engine.

3A-C Power · Post by **3A-C Power** » Tue Dec 14, 2004 7:49 pm

Some of us have changed to Weber carbs - it gives you more power for sure. Rebuilding is also a good way to fix it, it's cheap, not too difficult, and it solves the problems. Really watch out for vacuum leaks, make sure everything is sealed between the carb and the cylinder head, and all the hoses around the carb. Those can make an otherwise perfect engine drive like crap.

shogun · Post by **shogun** » Fri Apr 01, 2005 9:10 am

how much more power can be had with the weber carb? willa spacer do me any good?

arbskynxnex · Post by **arbskynxnex** » Wed May 04, 2005 3:41 pm

I would get a carb from a 4a instead of rebuilding the stock one. I ran my 4a with both the carbs on and I noticed a LOT more power from the 4a carb. With the 3a carb it was like I never replaced the engine at all, same power (or lack of), slow up hills, etc.

Typrus · Post by **Typrus** » Wed May 04, 2005 10:42 pm

Is there oil on the firewall. Just a hunch. If there is oil on the firewall, replace the fuel pump. Also, smell your oil for gas.

post_a_query · Post by **post_a_query** » Thu May 05, 2005 10:06 pm

<span style='font-size:14pt;line-height:100%'>alrighty,

while waiting for the shocks to be re-produced, i was wondering...

when swapping the weber carby, will any, some or all of the vacuum and/or emissions lines?

what do you figure the ccarby and plate cost/ from where (recommended)

now i'm wanting to get her to be a little nutty, not drag 'em down the road, but you know... have some roar?

rromig

ted... any news on the shocks?</span>