I have a 502mag with a whipple charger. I am having a problem with the RPMs. The motor runs fine up to 4000 RPMS... then no more power. I changed head and intake gaskets and now this problem occurred, Looking for some ideas to help me. I have spent a ton of time so far and I am running out of ideas. The motor has no codes through a merc computer, but the whipple comes up with a code for rpm signal. I also put a New harness, and fuel filter on. Please help

I'm in the same situation. I have done some of the same things you have and had no results. I have contacted whipple but I'm waiting on Dustin to answer a few of my questions. I have a good friend of mine working on my boat who knows whipples very well, if we come up with a solution I will be sure to pass it on. Good luck.

Are you seeing boost on your boost gauge and how much? I know this probably isn't your problem but is your belt tight enough,Smitty

It is just starting to build boost. I will double check the belt tension thanks

25chkmate, Did you have the whipple on before you changed intake and head gaskets? Did it run ok before changing the gaskets. I bet Dustin will know what to try out to fix your problem.

I was under the impression a whipple would be at 5 plus psi of boost by 4000 rpm's so you might be onto the problem. If your propped for the blower but you don't actually make boost because of belt slipping your boat will pull to 3000-4000 rpm's then just be dead feeling,I had a upper pulley bolt and key fall out on my procharger before and it just pulled to about 3500 and wouldn't do anything else or make any boost. Hopefully this is your problem too,Smitty

would that bring up a code 11 on the whipple charger?

I had the whipple on before and it ran great. I had to change the gaskets because of other problems

OK, so something probably changed upon reassembly.
I just rebuilt my motor with a whipple. There sure is a lot of wires and hoses. You are running injected I'm guessing? If it says something about RPM, maybe it is not sensing the distributor. Mine has a plug that is in between the stock connector and the distributor. It might be something really easy, so I would definitely check for any connectors that may have come loose.

This is pretty simple, getting 11 code, no rpm, that means its not getting rpm signal. 2 things can be wrong, the wire connection, purple/white wire is not connected in some way or the extra ecm is got a burned chip and cannot see rpm. This can be from water, etc. but check the wire, if checks out ok, the ecm would have to come to us to see if we can update or replace.

Thanks,
Dustin