need some help with my jet ski problem...

I have finished my white jet last night, everything ready to go, fired up for a few minutes at home with the hose connected and it worked just fine. Today i took it out to the lake and for about 15-20 minutes took it easy to let the motor break in and to make sure everything works perfectly. Did a sub, both bilge pumps got the water out quickly all well.

I ran 40:1 oil so it would lube up better for break in. After playing around i told my friend (who was on my blue stock engine ski) to race, to see how much faster it is. White one pretty much destroyed my blue one, with extended worx plate, intake grate, and tubbies it grabed on to every bump and wake without a problem and kept pulling.

for about 30 seconds i held it at WOT then the ski just died and i flew over the bars at full speed :splatt:

Last time i had this happen was on my blue one when i was low on gas and held it at WOT to see how fast i get accross the lake and back, but i had a full tank of gas. I kept trying to turn it over, and it turned over but just didnt start. It sounded like it wanted to start but didnt. My friend towed me back to shore.

I checked my spark plugs and they were both the same, i checked the spark on both plugs they both had the spark. I looked inside the cylinders and both pistons went up and down without a problem. I checked all my lines and they were all connected.

After playing around with it for a bit i was able to start it with the engine sounding kinda weird, i had to pull on the throttle just a bit to get it to stay running but once i let go it dies, so i turned up the idle just a bit... wich opens up more air into the engine and it had a weird idle, sounded like it was running on only one cylinder, but both plugs had a spark.

So what i did is disconnected one wire to the spark and tried starting it and it idled the same, then i did the same with other spark plugs wire and it would not even start at all, didnt even sound like it wanted to start. So this confirmed that i only had one cylinder working, even if i had 2 sparks firing.

I was thinking maybe the timing messed up in the electrical box, but i dont think there is a way to adjust it? its not like a car, on jets it either has a spark or doesnt and there is no way to adjust the timing of the spark i dont think??

my second guess was maybe one of the carbs wasnt shooting gas into that cylinder?? i put some gas into both carbs but i didnt really have any luck with making it work that way. Any ideas? suggestions?

this jet was waaay more fun that my blue one, i got arm pump after a few minutes haha, but now :banghead:
thanks much!
 

norcal ex

X-H2
Location
San Jose, CA
if one is getting spark that can only be a couple things. check compression... if even, get new plugs, if still not working, send your coil to john at jet ski solution.
 
if one is getting spark that can only be a couple things. check compression... if even, get new plugs, if still not working, send your coil to john at jet ski solution.

no no, both are getting sparks.... but only running on one cylinder... ill go check compression right now
 
30psi at one cylinder...... ok can someone calm me down on this one, and why this would happen? what are my options? could i have blown an oring? :frown:
 
Edit because you found your problem.

A new motor needs broke in correctly and in that time you can adjust your carbs and make sure everythign is good enough for a WOT run.

You need to tear it down to see what is damaged. More that likely you will need a hone job and a new piston and rings. At the least.
 
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Edit because you found your problem.

A new motor needs broke in correctly and in that time you can adjust your carbs and make sure everythign is good enough for a WOT run.

You need to tear it down to see what is damaged. More that likely you will need a hone job and a new piston and rings. At the least.

fudge that!!! lol, a blown ADA O-ring possible? wiseco says 20 mins break in, it broke in it for 20 minutes, atleast i think i did, but if not the oring what possibly happened, blew my rings into pieces? and scraped up my cylinder wall?
 

jetskiking

Im done sanding!!!
Location
Dallas Georgia
You should always run two tanks through on breakin. You should also avoid wide open throttle so it probably needs a top end on at least that cylinder. I would be surprised if its an Oring. You should also double oil more like 25 or 30:1 on those first tanks. I usually double oil the first tank then decrease the oil on the second until I'm at the proper mix on the third. I would pull the head and see how bad it is. You probably stuck a ring or something. Maybe you could get by with rings and a hone but you wont know until its opened up.
 
You should always run two tanks through on breakin. You should also avoid wide open throttle so it probably needs a top end on at least that cylinder. I would be surprised if its an Oring. You should also double oil more like 25 or 30:1 on those first tanks. I usually double oil the first tank then decrease the oil on the second until I'm at the proper mix on the third. I would pull the head and see how bad it is. You probably stuck a ring or something. Maybe you could get by with rings and a hone but you wont know until its opened up.

ahh yaya!! well whats the deal with the wiseco manual saying "break in period is 20 minutes" !!! ???

ill get up super early tomorrow and yank the head off and see where i stand. Ill end up doing a hone on both cylinders and maybe new rings, unless its pretty bad....
 
a blown ADA O-ring possible?
The o-rings are not what holds compression on a head. That little o ring will not hold up to all of that compression. The aluminum of the head sits on the sleve of the cylinder and that is the sealing surface that compression is held in with. The o-rings are there for waterseals.

Do a quick google search for 2 stroke break in. Almost everybody says the same thing. Wiseco probibly wants 20 minutes every ride. Wiseco pistons are lighter that stock which makes them expand in the heat faster than the rest of the motor. So the motor has to be warmed up slowly so that the piston clearance won't be an issue.

Good luck
 
i followed the wiseco manual.... wich says....

1. Use the same gas/oil mixture during break-in as you normally use.
2. Allow 15-20 minutes for break-in of new pistons and/or rings.
 

h2odesperado

Pin it to win it
Location
Charlotte, NC
t 15-20 minutes took it easy to let the motor break in

40:1

for about 30 seconds i held it at WOT then the ski just died and i flew over the bars at full speed :splatt:


oops... mistakes right there. I hope its just a ring needs to be reseated or something. Good luck, I hope its something simple.
 
Y

yamaslut

Guest
should have gotten ProX pistons.... they are safer to run than Wiseco... especially for newbys
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
What happened is this:

Brand-new engine.
40:1 oil for breakin (needs to be fatter than that)
Going WTFOT without tuning carbs.

You, sir, have just blown a topend.
 
Y

yamaslut

Guest
What happened is this:

Brand-new engine.
40:1 oil for breakin (needs to be fatter than that)
Going WTFOT without tuning carbs.

You, sir, have just blown a topend.

you don't need to double up on oil for breaking it in (I was told)
what do you recomend??
 

Crab

thanks darin...noswad!
Location
Seattle
I concure, 2 tanks at 25/1 mix, no sustained full throttle at all (blips ok), make sure jetting is not to lean, vary engine speed .
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
you don't need to double up on oil for breaking it in (I was told)
what do you recomend??

You're right, you don't need to. However, I wouldn't run WOT under those circumstances.

The combination of the factors I listed made it blow.
 
the last 3 engines I have broken in have gone thru this procedure:

approx 25:1

5 minute idle or so on the trailer with hose

then take to the pond...allow a 10 minute heat cycle on trailer with boat in water.....bumping the throttle occaisionally

LET IT FULLY COOL


take it out then and run low rpms with lots of throttle blipping.....absolutely NO WOT!!!!!!!!!!!!!




you need to heat cycle a brand new engine


sounds to me like you had a textbook lean seizure....live and learn!
 
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