2001 Sea Doo Challenger 240 EFI

[jasontaylor1974]

( A Little history first but not necessarily relevant) I have a 2001 Sea doo Challenger 1800 240hp EFI with a fresh rebuild. When I got the short block back and put it back in I bypassed the oil injection and I am running premix as I have done with all of 2 stroke projects in the past. Everything went well through break-in running 25:1 for the entire break-in procedure and following the break-in procedure as instructed. After the break-in I switched to 50:1 and all was well I had to adjust the TPS as it was off but no big deal heavy smoke cleared up and was running well. ( Now for the issue and question) My son in-law took off from the dock and everything was good for about 20 minutes then I see him come to stop and look in the engine compartment then pull it back to the bank. Upon looking I see that the lower voltage regulator/ rectifier has melted down so I loaded it up. I replace both regulators/rectifiers and attempted test it out. It has difficulty staying running at idle and will die multiple time then idle will race up at other times but even when I manage to get it away from the dock it has no power and bogges out. I have checked everything electrical except the harness’s. The fuel pressure appears to show high at 35 to 40 on start up and then up to 50 when idling. What do think could have been affected to cause this by the regulator/rectifier melting down?

 

[Tim75]

( A Little history first but not necessarily relevant) I have a 2001 Sea doo Challenger 1800 240hp EFI with a fresh rebuild. When I got the short block back and put it back in I bypassed the oil injection and I am running premix as I have done with all of 2 stroke projects in the past. Everything went well through break-in running 25:1 for the entire break-in procedure and following the break-in procedure as instructed. After the break-in I switched to 50:1 and all was well I had to adjust the TPS as it was off but no big deal heavy smoke cleared up and was running well. ( Now for the issue and question) My son in-law took off from the dock and everything was good for about 20 minutes then I see him come to stop and look in the engine compartment then pull it back to the bank. Upon looking I see that the lower voltage regulator/ rectifier has melted down so I loaded it up. I replace both regulators/rectifiers and attempted test it out. It has difficulty staying running at idle and will die multiple time then idle will race up at other times but even when I manage to get it away from the dock it has no power and bogges out. I have checked everything electrical except the harness’s. The fuel pressure appears to show high at 35 to 40 on start up and then up to 50 when idling. What do think could have been affected to cause this by the regulator/rectifier melting down?

Start with a compression test to rule out mechanical damage. Must be checked with all plugs out, and WOT. Should be more than 125 psi and even on all 6.

While the plugs are out, take a close look at them.

Fuel pressure should be 35-37psi at all times. High pressure means uncontrollable rich fuel condition. With your efi pressure gage connected, turn key ON. Pressure should be 35-37psi. Too high? Probably bad regulator. Too low? Bad pump or regulator. When you turn the key OFF, how long does it take for the pressure to drop? Instant- possible leaking injector(s). Several seconds- more normal, but could still be an injector issue.

Idle out of control- check all the bleed system hoses. That old tired rubber hose is prone to crack and split causing vacuum leaks that cause a lean condition and high idle. You can use tigon hose for replacement. (weed-eater fuel hose.)

Regulators- have battery tested. Including a load test. Sometimes they develop an internal short that can kill your regs.

Visual- inspect wires from trigger. They (6 wires) come out from under the flywheel to a connector aft of the flywheel. Is the insulation good or crumbly? If crumbly, you will need a trigger.

I have the same engine and boat.

 

[jasontaylor1974]

Start with a compression test to rule out mechanical damage. Must be checked with all plugs out, and WOT. Should be more than 125 psi and even on all 6.

While the plugs are out, take a close look at them.

Fuel pressure should be 35-37psi at all times. High pressure means uncontrollable rich fuel condition. With your efi pressure gage connected, turn key ON. Pressure should be 35-37psi. Too high? Probably bad regulator. Too low? Bad pump or regulator. When you turn the key OFF, how long does it take for the pressure to drop? Instant- possible leaking injector(s). Several seconds- more normal, but could still be an injector issue.

Idle out of control- check all the bleed system hoses. That old tired rubber hose is prone to crack and split causing vacuum leaks that cause a lean condition and high idle. You can use tigon hose for replacement. (weed-eater fuel hose.)

Regulators- have battery tested. Including a load test. Sometimes they develop an internal short that can kill your regs.

Visual- inspect wires from trigger. They (6 wires) come out from under the flywheel to a connector aft of the flywheel. Is the insulation good or crumbly? If crumbly, you will need a trigger.

I have the same engine and boat.

Thanks Tim75. I forgot to mention but I checked the compression as one of my first checks and all cylinders were 140 psi. I also tested the trigger and stator per the manual and they tested goog. I am at this point thinking there may be an issue with the harness connection located beside the regulator/rectifier that melted down. I pulled the connection out of the securing bracket and moved it around while idling and it began to backfire so I am going to try testing the harness and connections today and I will post what I find.