Mercury 240 Sport Jet Issue

[Arctic 1000]

Hello All,

Iv’e got an Outlaw Lynx with a 240 Sport Jet. The boat and motor have been extremely reliable and I’ve never had any kind of issue until now.

The boat starts and idles fine, operation from idle to 4100rpm is good. From 4100 to 4800 the engine seems to run like the choke is on. 4800 to wide open engine runs fine.
Things I’ve already done,
changed lift pump
changed fuel filter and fuel water separator.
Run Mercury #1 fuel conditioner
Changed out reeds
new set of spark plugs at beginning of season.

Im not getting any kind of beeps or alarms and the boat otherwise works perfect. Any help would be much appreciated, I’ve got a hunting trip with the old man coming up and I’d really like to find the issue!

Also if anyone knows of a Sport Jet Guy in the Grande Prairie area that would be great too.

Thanks.

 

[NoBrakes!]

good luck sir, please keep us posted. I would imagine Redline would know their way around a 240?

Does the boat have a heater that runs off engine coolant? I have heard bad things about sport jets and heaters....

 

[Arctic 1000]

No heater, stereo or anything else in my boat, she’s pretty plain Jane. I imagine Redline may know a few things about the 240 but I’d like to find the issue without breaking the bank if possible.

 

[neilsleder]

What year of 240? Newer one with an alternator or a older one with a stator. The older ones magnets would fall off or come loose and cause issues. One thing to check that nobody thinks of is your exhaust hoses. If you have a burnt one it will choke out the motor and do what you explain.

 

[neilsleder]

Jet craft is another good one to talk to or exact welding in pg.

 

[S.W.A.T.]

No heater, stereo or anything else in my boat, she’s pretty plain Jane. I imagine Redline may know a few things about the 240 but .I’d like to find the issue without breaking the bank if possible

Thats not how boats work lol

 

[Cableguy]

Break out another thousand

 

[snoflake]

coil packs possibly. Outlaw may have a used set from an old engine kicking around. Try unplugging one at a time and run it to see if you can find one that’s misfiring or acting different. Also, change the plugs again. Doesn’t take much to have a fouled plug that acts up. I had a coil pack that had small burn hole in the side.

 

[Arctic 1000]

Thanks very much for all the replies, I will double check the exhaust hoses and try a new set of plugs. Also good call on the coil packs. I’ll keep you posted on how it goes.

 

[Arctic 1000]

What year of 240? Newer one with an alternator or a older one with a stator. The older ones magnets would fall off or come loose and cause issues. One thing to check that nobody thinks of is your exhaust hoses. If you have a burnt one it will choke out the motor and do what you explain.

It is the newer 240 with alternator.

 

[Arctic 1000]

Well I changed all the plugs again and replaced a coil pack on hole #5. Seemed like all the other plugs were firing good but #5 plug still looked new.
Also double checked for exhaust leaks and ran the boat with the engine covers off to eliminate that possibility.
I've got a set of plug wires on order as well and am really hoping that fixes my issue.
If not I did talk to the guys at Jet Craft and am hoping they can offer some assistance!

 

[Arctic 1000]

Welp, installed the new plug wires and a new battery just cause I needed to spend an extra 200 bucks, took the boat to Exact Welding in PG today and they found the issue in about 5 minutes. Turns out the injector harness was chaffing on the silly clips that hold it in place! What a dumb design… Could have fixed it myself for about 3 dollars, piece of loom and a few zip ties.
Took er for a run in the Nachaco and she’s all good!