I have a stock carb in my 440, I have a 180 jet in it and it runs really strong. But I have heard if you put like a FCR or Edelbrock carb on, it makes a big difference. Is this true, because I can't imagine it making that much of a difference.

And the GT Thunder Rev Box, what rpm does it shut down at and do they make a difference in performance?

 

that rev box is good. it won't necessarily increase power, but the throttle response is better because it also advances your timing 6 degrees like a sparks timing key for example. do NOT run this with a sparks timing key though. i think it adds 1000 rpms, but am not sure.

the FCR carbs increase throttle response substantially. the throw on the throttle lever is much shorter than stock, which makes the throttle response improve. the power increases are good with it. i don't think it is as good as most people say though. i would try to go down on your mainjet in your bike and it should run quicker.

 

I agree that 180mj is no rich. Stay away from the Edelbrock carb. I can't see spending $600 for an FCR carb and gain only 2hp, yea your throttle responce increases.

I have a friend running a 440, 11.5:1 piston, stage two Hot Cams, ported and polished by Craycraft Racing and running damn good with 45pj, 168mj, 700ft above sea level.

 

Yeah I am having a hard time letting go of the cash to buy a new carb, even though I want one pretty bad. I have seen them on ebay for around $300.00 [img]i/expressions/face-icon-small-frown.gif[/img]

Cal I saw in one of your earlier posts that you had the GT Thunder Rev Box and wondered how the timing advanced affected the performance of your engine. I am running a WB Box and the thing doesn't seem like it ever hit the limiter.

As far as the jetting I was running a 178 and my plug was running white so I put a 180 in. I know that isn't much more but I thought I would give it a shot.

Appreciate the info!