Super Jet Blown motor....FML....where to start?

[icecoled007]

Well F.....

I have been having an issue with my spark plug not burning even lately and then this happened....

Took it out today and rode all day. Was on a lake run (riding 1/3 throttle) and throttled up to jump and it cut out like it was cavitating.

Wont throttle past 1/3 throttle (smoothly) now.

Took it out on the trailer and tons of white smoke and a burning smell. There goes the motor I guess..... live and learn.


I was really pissed off and cursing at the whole world. Never blown a motor and I dont if it was my fault or what.

I felt super ty because I feel like it might be my fault for installing ADA head and B-pipe. But, I am feeling a little better now I realized its a 15 year old motor and the previous owner had it super lean (white plugs when I bought it) I realized it I will have to brace this as a learning opportunity. Its part of owning these these things and I will know more than most.


I never rebuilt a motor before, can you guys help me along the way? I will be reading everything on here and taking my time.

 

[Matt_E]

How do you know it's blown? Have you done a compression check or pulled the head?

 

[js/sj]

^^^^^ what he said ^^^^^

 

[icecoled007]

Humm it all looks ok. I used my harbor freight compression tester and got 120 in each cylinder....when I tested it about a month ago with the same tester I got 145 in each cylinder. Whats going on?

 

[icecoled007]

RIght before I went to the lake I trimmed by spark plug wires back.... could the problem be there?

Those bubbles aren't water are they.... if so what should I do?

 

[Fx1]

I wouldn't trust a harbor freight tester throw that away. If I had to guess looks like water was making it's way into the cylinder steam cleaning your pistons. Did you rejett your carb when you installed the b pipe? Make sure the filter inside your carb is clean. Properly torquing the head is a must and make sure all o rings are in their grooves when installing. I can't tell for sure but looks like your missing an o ring on the right dome in your pic???

 

[onedumbtrucker]

The water droplets are likely just from pulling the head off. There is no way to stop any water that is still in the head from getting all over everything when you take it apart. It looks like the rear cylinder is rich or not burning properly from the carbon on the rear piston top.

The cylinders look pretty good. I would pull them off, measure the bore to see how worn they are. Also check the pistons for cracking and wear, especially around the ring lances. If no signs of damage I would put new rings on the pistons, give the cylinders a quick hone and slap it back together.

These engines don't last forever and if you don't want to break it don't ride it The manuals usually recommend replacing pistons rings every 25-50 hours which seems a bit ridiculous but that is nature of the 2-stroke engine. Especially when you start modifying them for performance.

Edit - the o-ring is not missing. One is still in head and one is stuck to the top of the cylinder. No worries there.

 

[rollin5150]

Looks like you are leaking water into your cylinder. Did you torque the head down correctly?

 

[Matt_E]

The water droplets are likely just from pulling the head off. There is no way to stop any water that is still in the head from getting all over everything when you take it apart.

All cooling water should have drained out the bottom of the exhaust manifold by the time you pull the head. There isn't any water left up there.

The manuals usually recommend replacing pistons rings every 25-50 hours which seems a bit ridiculous but that is nature of the 2-stroke engine. Especially when you start modifying them for performance.

What manuals are you getting those numbers from?

 

[tor*p*do]

The manuals usually recommend replacing pistons rings every 25-50 hours which seems a bit ridiculous but that is nature of the 2-stroke engine. Especially when you start modifying them for performance.

WOW, I should be going through 4 sets of pistons per summer?
Not quite!

 

[Freakrider]

I think most guys on here change rings every 250 to 500 hours lol...

 

[icecoled007]

Drained gas, flushed everything, put new gas in,

As I was putting the head on I felt a piece of metal come off my rear cylinder head o-ring. It was a small chunk but I am guessing thats my sign.

The motor sounds like its "grinding" there is no real loss in power, just sounds like chit. Tons of white smoke comes out (more than normal) and there is excess oil in my exhaust.

Top end looks ok, is it possible for the bottom to go and the top to be ok?

 

[Matt_E]

Can you turn the motor over easily by hand (with the head off)? Does it make noise when you do that?
White smoke, "excess oil", and no real loss in power don't signify a blown motor or one that's about to go out.

 

[icecoled007]

Yes I can turn motor by hand. I sounds like scraping, but it sounds like its coming from my pump. (Prop slightly brushing wear ring)

 

[WaveDemon]

your front cylinder is really clean, too clean. I suspect either no spark on that cylinder (washed by fuel), or an o-ring leak. Also, it looks like your rear cylinder is a bit rich.

 

[Matt_E]

Yes I can turn motor by hand. I sounds like scraping, but it sounds like its coming from my pump. (Prop slightly brushing wear ring)

Then your crank is probably not going out. You should pull the pump and investigate the noise.
But WaveDemon is right, you should also try to find out why the piston wash looks the way it does. I think it's likely your bogging/bad running was dropping spark on one cylinder or having a stuck open needle & seat in that side carburetor.

 

[Al//gsx//sj]

Top end looks ok, is it possible for the bottom to go and the top to be ok?

yep, I rode my gsx about 15 minutes from Destin's oulet to the landing under the bridge. bearing on the counter balancer shaft let loose, put a hole in the lower case and a broken Rave Valve
pictures -- http://www.greenhulk.net/forums/showthread.php?59410-carnage-from-last-week...&highlight=

 

[icecoled007]

I found this when installing my head. It feels hard but it doesent look like it caused any damage. Its sitting on one of those handheld lighters to give you size reference.

 

[Idok]

I think most guys on here change rings every 250 to 500 hours lol...

I think most change rings when they change pistons!



to the OP...

your cyl looks fine, as does the head....pull the pump out to see if the prop is grinding on the wear ring.....

just pull the pump and spin it over by hand again with the head off.....

 

[icecoled007]

Ah, crap. I am a dumb ass. Guess this solves the cavitation issue.

Would this cause any problems?

Now I know where that burning smell is coming from. I never saw this in there when I was at the lake.....must of got delogged from driving and starting it up.

Unfortunately, when I started it up again its still not 100%. Sounds like I gotta pull the pump and make sure everything is clear.