Super Jet cylinder pics 2 tanks after fresh top end

[Waternut]

Air in the fuel line is the most likely culprit...it happens. The first fix for that is to let it idle for 5-10 seconds before trying to rev it after removing fuel lines. If the tank was low on gas, that's another culprit. A leaky primer can cause it too but I'm betting it's one of the other two. If it does that again, pull the throttle. Seems like the last thing you should do but it's the only real solution. The plugs get super hot and they ignite the small amounts of fuel and maintain the ignition. The additional fuel cools the plugs and stops the engine.

I've had it happen for 5-10 seconds after a ride and the engine got hot enough to boil water instantly for a couple minutes. I also blew the head gasket once and didn't realize it until the engine shut down. That engine continued to run long after both of those. Hopefully it wasn't really 90 seconds but one of the guru's will have to chime in on what that will really do to the engine.

 

[BruceSki]

Make sure the carbs are in sync. I had this happen to me the other day. It would run away on the trailer. One butterfly would be open just a bit while the other was at idle. Revs to the moon.

Going through the carbs probably wouldn't hurt either and it doesn't take that long.

 

[superjetkev]

also check the throttle shafts, i had a ski that took off and it turned out to be a worn out throttle shaft.

i agree with motoman....take those carbs apart and have a looksie!

 

[McDog]

I had noticed that one was barely open when the other was closed before I put it back together. I tried to adjust it to no avail. I just ass+u+me'd that it came that way for some reason and quit messing with it. Hard to believe that that little bit of a difference could cause that strong of a reaction. It still seems that there wouldn't be enough air. I'm not argueing with you though because I have no idea.

Paul advised me to do a vacuum test on the cases just to be sure. pabloescobar has a minty set of oem 44's with a 64x intake sitting in his shop. Now may be the time to switch.

 

[Matt_E]

Why would you switch cases? Find out what's causing your problem and fix it. :veryhappy:

 

[McDog]

I'm not switching cases. Just carbs and intake manifold.

 

[BruceSki]

Yeah it only has to be slightly off from one carb to another to make it run away like that. Mine was barely noticeable at an idle.

The way I found out about it was while riding when I thought a plug wire came off cause it was only running on one cylinder. Pulled up on the beach and noticed the throttle only turned one carb cause the set screws rattled out. gobbed it up with loctite and haven't had a problem since.

 

[Big Kahuna]

Yeah it only has to be slightly off from one carb to another to make it run away like that. Mine was barely noticeable at an idle.

The way I found out about it was while riding when I thought a plug wire came off cause it was only running on one cylinder. Pulled up on the beach and noticed the throttle only turned one carb cause the set screws rattled out. gobbed it up with loctite and haven't had a problem since.

Yup, I chased that problem on a friends ski, could not figure it out, then just looked down the throats and bam........ Saw that one butterfly was open just a touch. This was after pulling the carbs twice, intake manifold and changing gaskets.

 

[Pablo]

I F !@#$%^&* -ing hate wrenching!

yup, i chased that problem on a friends ski, could not figure it out, then just looked down the throats and bam........ Saw that one butterfly was open just a touch. This was after pulling the carbs twice, intake manifold and changing gaskets.

 

[McDog]

No you don't. Shut up.

 

[Big Kahuna]

I F !@#$%^&* -ing hate wrenching!

Why do you think I have not been in a rush to get my ski together. Even though I enjoyed putting my ski back together the other night.

 

[McDog]

I hate chasing gremlins. I hate tuning. I hate riding a ski that isn't running right. I hate it when I think I have everything together and ready to go and it doesn't work. I hate taking a motor out after I just put it in. I hate it when start/stop switches stop working. I hate it when starters go bad. I hate it when solenoids go bad. I hate swimming my ski back from the middle of the lake. I hate getting towed from the middle of the lake. I hate spilling gas in my hull. I hate working on my ski when I'm supposed to be riding. I hate redoing things I have already done. I hate having to retighten my pole bolts. I hate it when my pissers aren't pissing right. I hate it when I cut my knuckle. I hate it when bolts strip. I hate it when my ski doesn't start. I hate losing washers/nuts/bolts in my hull. I hate corrosion. I hate having no idea why something doesn't work. I hate having to call Paul over and over again to bug him about my latest problem. I really appreciate his help.

 

[Waternut]

Paul advised me to do a vacuum test on the cases just to be sure. pabloescobar has a minty set of oem 44's with a 64x intake sitting in his shop. Now may be the time to switch.

So after reading your "I hate jetski's" rant, I have to ask...Why change the carbs? You just determined that the total loss plate was loose and the timing was all over the place. The carbs worked before total loss and they worked with total loss. The only difference was a slight hesitation off the bottom. You determined that the hesitation was most likely due to the total loss. From what I can see, the only thing that's making you look closely at the carbs is the runaway engine you just had.

I usually try to tweak my carb on the 61x/61x engine down to the 1/16th of a turn to make it perfect. The crankcase is leak free. Yet if I pull the fuel lines and let all the fuel drain, there is a very good chance that I'll get a runaway engine if I try to pull the throttle when first cranking it up. I'm not saying ignore the situation but sometimes a problem is a fluke that happened because the stars lined up and it'll never happen again. I'm just saying, give it another chance before you go throwing new parts at it.

 

[upstand2]

Does look lean.

 

[Idok]

single carb tuning FTW

next time it diesels like that, pull the throttle open..it will kill it instantly

 

[BruceSki]

single carb tuning FTW

next time it diesels like that, pull the throttle open..it will kill it instantly

F that single crap...... duallys make more power, they are worth the trouble.

Agreed on killing a dieseling engine though. with the stop button held.

 

[McDog]

I did and it didn't. That's why I removed a sparkplug.

 

[Big Kahuna]

pulling the plug will not always work, plus you get the crap shocked out of you in the process. Stuff rags down the throats................... chokes. Or start pumping your primer like crazy

 

[Waternut]

I did and it didn't. That's why I removed a sparkplug.

That sucks. I'm still wrenching on mine but if you need some help, just let me know.

 

[tor*p*do]

pulling the plug will not always work, plus you get the crap shocked out of you in the process. Stuff rags down the throats................... chokes. Or start pumping your primer like crazy

stick a potato in your tailpipe!
or a wet towel