Islandia Mercury Sportjet 240 EFI Gen 2 HELP needed running rough 5800 rpm WOT

Note: This site contains eBay affiliate links for which SeaDooForum.com may be compensated
Status
Not open for further replies.

SeptemberC

Active Member
Islandia Mercury Sportjet 240 EFI Gen 2 HELP needed

I am starting a new thread for this even though I originally requested help for this issue in my other LONG thread.

HISTORY: Wednesday June 7th I had my Islandia tied up to my cousins boat. We both started up our engine to move the boats to an area that the wind wouldn't blow our boats into the shore. UNKNOWN: Did I turn my engine off first. We floated for about 2 hours and I had my dual battery switch ACCIDENTALLY turned to BOTH. I had an inverter hooked to battery 2. We were using it to be able to use a blender. We were getting blown into the shore again and I went to start my boat and "click" it wouldn't start. That's when I realized that the battery switch was set on BOTH. The marina sent a guy with a jump box but it had only been on charge for an hour. We assumed that it didn't have enough power to start my engine. My cousin towed my boat 20-30 min admittedly too fast. Most people on my boat were sitting on the back deck and the captains chair during the time we were floating and being towed. We arrived back at the dock at the house and I went into town and purchased a battery at Walmart and a battery charger. My husband installed the battery and "click" The bendex was raising on the starter but would not turn the engine over. UNKNOWN: Was this the same as when I first tried to start it? At this point my husband noticed some smoke coming from the starter and the dual battery switch. Thursday June 8th We replaced the dual battery switch and we installed a new starter w/solenoid 892339T01. Still the same thing happened when we tried to start it. We bypassed the battery switch and wired directly to the engine. Same result. NOW I was completely sick. . .REALLY. Ulcer. . .So I had someone tow me with the ski to the boat ramp and we put it on the trailer. We towed it into town and a tech at a boat service center first tried jumping the other solenoid (816108A2) it made the bendex pop up. So then he pulled the cover off the engine tried to turn the engine by hand and. . NOPE. He started taking the spark plugs out and water ran out. They then told us they couldn't help me and we left. That evening my friend who is a merc mechanic called me back and tried to calm me down and explained that it wasn't as bad as it sounds and for us to go out to the boat, pull the safety switch, pull the plugs and turn the engine over until the water stops coming out. Then to squirt some 2 cycle oil into the cylinders and put the spark plugs back in. We did that and by now its dark outside. I was so sick I had to go to bed. Friday June 9th, I got 6 new plugs. My cousins friend from Cincinnatti who is a Merc mechanic just happened to be at the same lake we were. He came over and looked it over and suggested that we take it to the water and run it. (At this point I was scared to death to put it back in the water . . what if the engine filled with water again. . . ) He had trouble starting it I assume because there was so much oil in the cylinders. I'm not sure what he did or touched because I was in the truck. . .But he got it running. After about 10 minutes of running it at idle, 1/4, 1/2 and WOT he brought it back to the dock at the house. It was running rough at anything less that 1/2 throttle and we had 5500 to 5700 RPMs Before all of this we had 6000 RPM. Assuming that the plugs were fouled from all of the oil we put 6 new properly gapped NGK BPZ8HS-10 plugs. NO CHANGE in performance. We ran it the rest of the day, floated, tried the best to enjoy our last day there. We ran a tank and 1/2 of fuel out.
HOME: We put another set of plugs in it and I purchased a couple coil packs. LAST YEAR I had an issue with low RPM and Dr. Honda kept telling me to check compression.. . I ended up finding a bad coil. Surprisingly enough the engine did not run rough or sound weird, just low RPMs. Replaced that coil pack and BAM 6000 RPMs. OK back to current. We tried switching coil packs around to see if it ran differently. Unfortunately we were in the driveway not the water so this wasn't the best scenario. I'll attach pics below along with what Cylinder # they came out of. We put a can of seafoam in it and took it to the river and ran it all day and ran the whole tank of fuel out. MY merc guy said by looking at the pictures he think its running lean. He suggested that the manual pump may be starving the cylinders and to rebuild it. By looking at the same pics Dr. Honda believes that it may be a spark issue. He suggested that we get an inline spark tester. We checked compression and Cyl # 1,3,5 had 110. Cyl # 2 had 100, #4 had 110 and #6 had 115. I filled the tank 3/4 full and put 2 bottles of Lucas Upper Cylinder lubricator and fuel system cleaner in it. The pump was rebuilt today and reinstalled. I also cleaned the throttle body with Throttle body cleaner and a rag, I DID not just spray it down into the the throttle body. We used the inline spark tester (in the driveway) it appears that all are firing. By the time we got everything put back together it was close to dark. We took the boat to the river and we ran it. It seems to run SLIGHTLY better but at no throttle it seems like it want to quit. It still runs rough at less than 1/2 throttle and we MIGHT have slightly higher RPMs. (DON'T take this statement as fact but it might feel like the throttle needs adjusted)
ALSO. . . THE throttle assist NO LONGER works. BUT WHY?? Thinking out of the box...WHAT could have happened during this whole process that would cause it to run rough, low RPMs and the throttle assist to stop working?
Please try to refrain from unhelpful negative comments. I have video (for sound purposes) I have pics of the plugs and I have several pics of the engine (as best I could) hoping that maybe someone would see the switch that says flip this so that it won't run rough, or the one that says flip this to increase your RPMs LOL
Another thought I just had. I always use quicksilver 2 stroke oil but I think the last 2 jugs I bought were NOT premium plus.

See pics below. I will try to add videos to you tube and post the links.

FullSizeRender.jpg
HE DID WIPE THIS ONE BEFORE I CAUGHT HIM TO BE ABLE TO TAKE PICS
FullSizeRender_1.jpg
FullSizeRender_2.jpg
FullSizeRender_3.jpg
FullSizeRender_4.jpg
FullSizeRender_5.jpg
IMG_2982.JPG
IMG_2983.JPG
IMG_2984.JPG
IMG_2985.JPG
IMG_2986.JPG
IMG_2987.JPG
IMG_2990.JPG
IMG_2991.JPG
IMG_2992.JPG
More pics next post
 
Last edited by a moderator:
Here are pictures of the spark plugs. I took these this morning after we were out lastnight after the fuel pump rebuild.
FullSizeRender(1).jpg
FullSizeRender_1(1).jpg
FullSizeRender_2(1).jpg
FullSizeRender_3(1).jpg
FullSizeRender_4(1).jpg
FullSizeRender_5(1).jpg

Still can not track down why the throttle assist is not working. Is there possibly a fuse? How does it work? Gen 2 240 EFI
 
No real update.....

Does anyone have any additional thoughts....

It appears that cylinder 3 & 6 are running rich. DDT scan shows no faults. Fuel pressure OK, fuel pump rebuilt, spark plugs replaced, there has been no change. It runs rough, stumbles, I need to bump the throttle to keep in running at idle. It appears to clear up at 1/2 throttle to full throttle. RPM is down about 200-300 rpm. Throttle bump for steering assist does not work anymore. (It's the sensor type NOT the cable type)

Our plan for this weekend is to use a timing light on each plug wire to see if any are NOT firing all of the time.
Anyone else have any suggestions?
 
I can't help with the engine trouble but I may be able to help a little on the steering assist.

There is a cable that comes of the steering assembly in the hatch in front of the helm. As you turn the wheel it pulls on the cable. The cable has an adjuster like you would on a bicycle break.

I suspect the cable is either broken or not tight enough. If you reach into look in the hatch when you turn the steering wheel you will be able to tell if it is pulling. You can tighten the cable by turning the screw on part at the end of the cable where it meets the steering box

from there it should be easy to tell if it's just out of adjustment or actually broken
 
Took it to a Merc shop and they said fuel pressure was within spec., no codes/faults when hooked to computer. 3 hours later I know nothing more & no diagnosis.


Ok so...... using a timing light on all cylinders... they are firing and firing steady. After testing each cylinder we headed back to the dock approx 3/4 throttle for 2 to 3 mins. I turned off the engine and it would not restart. It would crank but not hit. We opened the engine cover to allow fresh air into engine compartment. Would not start. Waited a few mins.. .would not start. Hubby pulled all of the plugs and he says they all looked DRY and black (and hot). He said none were WET. He wiped them all down and put them back in. It started right up. Still running the same though.

As far as I can tell... it's running the exact same as it's been running.
The description of the plugs has changed ??
Still no throttle assist (electronic)
Idles at 900/1000 rpm rough.

WHAT IS going on with my Sportjet??
I'm attaching the report from the dealer below
FullSizeRender.jpg
FullSizeRender_1.jpg
FullSizeRender_2.jpg
IMG_3123.JPG
IMG_3124.JPG
IMG_3125.JPG
IMG_3127.JPG
 
Last edited by a moderator:
Just wanted to chime in because this happened to me on a 2stroke jetski...

You said you got water in the motor (from being towed too fast) - and it sat overnight before you restarted and ran it again? On my skis, I let that happen one time, and I had the same symptoms. The compression still checked out, but I lost RPMs after the restart. Unfortunately in my situation, water was able to get to the crankshaft, and corrode some bearings. Enough to slow the motor down, but not enough to grenade it completely. This wouldn't show up on a compression test obviously, but at the end of the day I had a couple bad crank bearings that wouldn't let the motor spin as high as it wanted. Split the cases and was able to save the entire top end, and the crank for that matter after replacing the bearings.

Hopefully this isn't the case for you, but that's what it worked out to be for me. Luckily I thought to split the motor before it detonated.... I have no idea if/how you would be able to check this on your boat without a full tear down.

I know its exhausting, and can get late, but the lesson I took was if you get the motor waterlogged (happens all the time for me when I sink a ski), drain it, spin the motor to get the water out of the top end and get it started ASAP, let it run a good while to get the oil back in all the little nooks and crannies, around the crank, and to force any moisture out. When I did this, the motor survived.
 
Throttle assist: Since it's electronic, it's on a circuit. Circuits are usually fused. Have you check all your fuses? I don't know where that one might hide.

Had a similar problem once: Wires corroded off the connector to the hi-pressure electric fuel pump. It would start and run, depending on how the wires rested on (or not) on the connector.

Not sure if 2 problems are related.
 
Status
Not open for further replies.
Back
Top