What in the world!!!!

[Higgins-LCHC]

I was riding last night and jumping a few boat wakes. As I came down on the last jump when I landed my ski died. I tried to restart it and it turned over real slow and then nothing. I got a tow back to the dock and pulled the plugs to see if it would turn over without them in the holes. Nothing but starter clicks. I looked at the plugs and noticed one had no gap on it. The rear plug looks fine and is a good color. The front plug has no gap and looks like someone has been chewing on it. I didn't hear anything bad from the motor when it died so I do not know where to start. Has anyone seen this happen to a plug before?
Higs

 

[WFO Speedracer]

Yep go ahead and pull the top end apart,something in there came loose,I am going to say a Rod bearing thats just my huess.

 

[SUPERTUNE]

Looks like the piston crown as come apart, probably cast piston?
The first pic does show a little bit of grey (on the plug that is OK on the gap) like it got overworked (might be caused by 1st cylinder losing power first) and was a little bit lean. Not real sure if the crank caused it, I just don't see enough shrapnel damage to the plug in your 1st pic to me, most of the time that I have seen cranks lose a bearing it goes slow with little bits of debris first, then takes out the piston and cylinder bore.

 

[stanton]

i wish you luck!

 

[DAG]

I have seen cranks lose a bearing it goes slow with little bits of debris first, then takes out the piston and cylinder bore.

humm wonder what that looks like... oh waituch:

 

[Higgins-LCHC]

Ok, so I pulled the head and it didn't look good. The rear piston is black as night and the front piston is full of little parts of metal. Looks like a grenade went off in there. The front dome looks like someone took a ball pein hammer and beat the crap out of it. I guess this is the start of a full break down and rebuild. Pictures say it all!

 

[WFO Speedracer]

I knew you were going to find something on that order,hopefully it was a ring that took a crap and not a rod ,you will know soon enough though.

 

[DAG]

well at least you dont have any scoring, (or from what the pic tells).

I just had this happen to me 2 weeks ago. (new crank, seals, bond, dome, piston, hone, and a bunch of time). dont have to much fun

 

[Higgins-LCHC]

well at least you dont have any scoring, (or from what the pic tells).

I just had this happen to me 2 weeks ago. (new crank, seals, bond, dome, piston, hone, and a bunch of time). dont have to much fun

I was hoping that it would just be something minor. I wonder if the domes come out of this PJS head. I can't tell. We will know when I pull the cylinders tonight and see the carnage down below.
Higs

 

[dbrutherford]

If it was me, I would find a 650 and do a conversion swap. Or perhaps a 750...

 

[WFO Speedracer]

Pjs heads do not have removable domes,you could send it to Group K and tell them to clean it up,they can mill some off the head and put it back almost like new.

 

[Higgins-LCHC]

Pjs heads do not have removable domes,you could send it to Group K and tell them to clean it up,they can mill some off the head and put it back almost like new.

What does something like this cost? Would it be cheaper to get a new head? What would you recomend?
Higs

 

[Higgins-LCHC]

OK, So I got the motor out and tore down the cylinders. Rings on the front piston had welded themselves into the piston head. I have included several pics. I am about to split the case and clean that all up. I am hoping that the bearrings are ok and not full of piston parts. Everything else looks ok. No scratching or marring of the cylinders, so I am happy with that. The questions I have are....Is the flywheel nut tightened with an impact or is it just that frickin hard to get off. I am assuming that the flywheel and stator need to come off before I can split the case. OR is there a secret to getting it apart. Thanks
Higs

 

[Higgins-LCHC]

More pics of the pistons. If you look at the under side of the pistons and note the black burnt pattern. What caused this. Was the front cylinder running lean and hot? Or could this have been caused by an air leak? I guess I will never know.
Higs

 

[ski4]

i wonder too????

 

[restosud]

could be lean.check your cases real good for cracks as debris can get wedged between the crank and cases.
check all bearings as well.
as far as the rings being stuck,it looks like it's just from piston being pounded by shrapnel.
good luck.

 

[WFO Speedracer]

I am considering selling my 550 reed motor or parts of it ,I just put a top end on it with new Wiseco pistons with the boost ports,it has less than 5 hours on the new top end,The cylinder has light porting done to it no transfers were messed with or port sizes altered.I would be willing to be sell the cylinder,head and pistons,it is still standard bore.I would like to keep the crankshaft for another project since its a trued and welded crank.LMK if you are interested.

 

[Higgins-LCHC]

could be lean.check your cases real good for cracks as debris can get wedged between the crank and cases.
check all bearings as well.
as far as the rings being stuck,it looks like it's just from piston being pounded by shrapnel.
good luck.

I am going to open the case tonight and take a look. I figured the rings were stuck due to the pounding.

 

[Higgins-LCHC]

I am considering selling my 550 reed motor or parts of it ,I just put a top end on it with new Wiseco pistons with the boost ports,it has less than 5 hours on the new top end,The cylinder has light porting done to it no transfers were messed with or port sizes altered.I would be willing to be sell the cylinder,head and pistons,it is still standard bore.I would like to keep the crankshaft for another project since its a trued and welded crank.LMK if you are interested.

I am going to open the case tonight and see if there is any damage. I am having a hard time getting the flywheel nut off. Should I be using an impact wrench? I do not want to mess up anything by prying on the coupler side of the shaft. Any tricks would be great. I know the cylinders are fine.(no scoring) I need to get pistons and a new head at this moment. Or have the head milled. Thanks for your help.
Higs

 

[WFO Speedracer]

I am going to open the case tonight and see if there is any damage. I am having a hard time getting the flywheel nut off. Should I be using an impact wrench? I do not want to mess up anything by prying on the coupler side of the shaft. Any tricks would be great. I know the cylinders are fine.(no scoring) I need to get pistons and a new head at this moment. Or have the head milled. Thanks for your help.
Higs

you are either going to have to get a strap wrench or a flywheel holder or an impact,the torque on that flywheel nut is 115 ft lbs its tight! Just a heads up, those are not stock pistons they are for a PJS engine,the stockers do not have boost holes,those particular pistons are no longer available from Wiseco,you have to get the pistons for the Kawi 550 reed and cut the boost holes in them if you want boost holes.