Sniper for 540
 

I have read through some threads on sniper installation. I have a pretty stout 540 and docking is a bit of a pain slipping in and out of gear. I think I will be running the sniper xflow. I am wondering about instal height as I have limited hatch clearance with a 3 inch flame arrestor. I wouldn’t be controlling my timing , just replacing a qft850 with the throttle body. I am running a Weldon A600 fuel pump and went with a return regulator so I would just have to swap out the fuel regulator which will make the instal much easier.

If you are just going to run an electronic carburetor and not full EFI with timing control I would not do it. If your only issue is with idle I would just run the carburetor and use a programmable ignition box such as a Daytona Sensors. It would fix your only issue. With the throttle body only setup I wouldn't guarantee it would solve your problem.

Best 600 bucks ive ever spent boating was on my Daytona Sensors CD1 box. Made my 565's idle - everyone says its a much better product than MSD so youre killing two birds......

As rookie said, the timing control is what also makes efi idle and go in/out pf gear good compared to a carb that has idle set right. Spark stabilization (In case you dont know what it does) adds/subtracts timing as your engine idles above and below your target rpm. Yes, the Iac will be part of this too but it can only do so much, Smitty

Thanks for the replies ! I looked at the Daytona sensors box and it looks pretty straight forward !

Do you have your timing locked out?

Timing is not locked out presently. I have a pro billet msd ignition.

+3 on the Daytona Sensors. I tried everything with my MSD including locking it out. The Daytona Sensors with the right program rocks. I had to do a little custom timing ramp below my set idle speed to smooth out the in gear transition while docking. Now it runs better than EFI. After watching detailed testing on Engine Masters with Carb vs. Throttle Body EFI I would never do it. Cylinder to cylinder fuel distribution was way better with a carb vs Throttle body EFI. I almost made that mistake myself. I highly recommend a 1" 4 hole spacer with a 1" open spacer under your carb it helped me a ton. With my 524 BBC I can idle at 650rpm in gear even with a 242/252 @.050 cam. What's amazing is the improvement with cold starts, no choke and about 30 seconds of warm up even in cool weather she's good to go.

Thank you. I am definitely going to go that route. I have no clearance for a carb spacer. Unless I cut a hole in the hatch !