I'm about ready to get rid of these carbs and go buy a holley efi kit. The current setup I have runs ok but has a huge problem with flat spot/lean stall at low engine rpms and only small changes in the pedal. Like the kind of driving you do every day. I've changed pump cams, squirters, jets and this current frankencarb just wont tune.
The original carb from this thread, a gold finish speedmaster holley clone. 4 years ago it was only $150 or so, now near twice the price. After all my fiddling around with it I snapped the baseplate.
After putting the new baseplate on things were fine until I stripped a bowl screw changing the jets. The rest of the carb that came with the baseplate had an electric choke I didn't want to deal with so I tore apart a used holley 7448 I bought on ebay a while ago for $120 and used the main body from that after making sure it was all cleaned up.
The frankencarb has the speedmaster bowl assembly, metering block, and squirter. Using the ebay 7448 main body, the baseplate from the unnamed holley clone. Didn't want to mess with the electric choke on the main body of this clone but its my next option.
I think that the 7448 has been modified or has some larger venturi that are too big to work for this. Changing to this main body I had to increase the jets quite a bit to get cruise and WOT not to be lean compared to the speedmaster body.
If I feather the gas it accelerates fine. mid-full wot has a small stumble but not bad. Light acceleration is more pronounced stumble that is worse the slower the engine is going. If I'm not careful it will stall/lean pop out the carb. A holley sniper setup with fuel pump looks to be about $1400 plus tax and shipping, comes with a 2 bar map so that should be more than enough for what I'm doing. Until then, continuing to mess with carb.
The original carb from this thread, a gold finish speedmaster holley clone. 4 years ago it was only $150 or so, now near twice the price. After all my fiddling around with it I snapped the baseplate.
After putting the new baseplate on things were fine until I stripped a bowl screw changing the jets. The rest of the carb that came with the baseplate had an electric choke I didn't want to deal with so I tore apart a used holley 7448 I bought on ebay a while ago for $120 and used the main body from that after making sure it was all cleaned up.
The frankencarb has the speedmaster bowl assembly, metering block, and squirter. Using the ebay 7448 main body, the baseplate from the unnamed holley clone. Didn't want to mess with the electric choke on the main body of this clone but its my next option.
I think that the 7448 has been modified or has some larger venturi that are too big to work for this. Changing to this main body I had to increase the jets quite a bit to get cruise and WOT not to be lean compared to the speedmaster body.
If I feather the gas it accelerates fine. mid-full wot has a small stumble but not bad. Light acceleration is more pronounced stumble that is worse the slower the engine is going. If I'm not careful it will stall/lean pop out the carb. A holley sniper setup with fuel pump looks to be about $1400 plus tax and shipping, comes with a 2 bar map so that should be more than enough for what I'm doing. Until then, continuing to mess with carb.