Post by dirtkid857 on Apr 8, 2024 11:26:23 GMT -5
First post here, I have come seeking advice and your technical expertise ...
Here’s what I have going on…
My son’s 2004 PDub blew up last week as it looks like it leaned out and had a piston to cylinder wall touchdown. At this event the bike was bone stock from what I was told by the person I purchased it from and “had low hours”” blahh blahh.
I will Post pics of first blow up and what the plug looked like at the time of each event In sequence.
So after the bike tipped over and blew up last week I ordered a 60$ Amazon jug and piston kit.
It seemed to be of decent quality for a 60$ top end kit, home looked good, cylinder wall appeared to be round… I gapped the rings to the OEM spec and installed the top end kit.
I then installed a new plug, pulled the oil injection line off to rule out a non performing injection system and cleaned the carb very well.
At this time Still had the #70 jet and I even lowered the clip on the needle to second to bottom
To ensure good line for break in….
I filled the tank with 40:1 premix …
Broke bike in with 3/4 heat cycles on the stand ….
Seemed to run okay but def would not open up and rev out.
I adjusted the pilot to 2 3/8 turns out per Yamaha.
Bike still broke up a ton.
Pulled plug and it was black and wet …. Plenty of lube and fuel..
I then raised the clip back to 2nd down from top..
Had my son ride the bike around the house 5/6 times when he fell over the bike was running decent but not great.
He fell over and bike went to WOT and I ran over and picked it up and it said bahhhhhhhh and died.
Went to kick it and it was locked up.
I was very angry to say the least. 
I then rolled the bike down to the garage and tried to turn it over with my hand, one more time, and the engine was still locked up and would not kick over.
 got frustrated and put the bike away for the night as we were supposed to race our first race of the season the next day and I left it until Saturday afternoon.
My son wanted to ride something so I put him on the Stacy while I was screwing around with the PW and lo and behold now it turns over and is not locked up. 
Has anyone ever seen this happen before?
I don’t think it was Hydro locked because I pulled the plug out see photo and it looked reasonably Lean……
Is there much of a difference between the second clip up from the bottom on the needle and the second clip down from the top on the needle to lean the bike out to where it would get that hot and lock up especially with 41 premix in it?
I’m wondering if there’s something else going on possibly crank seals?.
Here’s what I have going on…
My son’s 2004 PDub blew up last week as it looks like it leaned out and had a piston to cylinder wall touchdown. At this event the bike was bone stock from what I was told by the person I purchased it from and “had low hours”” blahh blahh.
I will Post pics of first blow up and what the plug looked like at the time of each event In sequence.
So after the bike tipped over and blew up last week I ordered a 60$ Amazon jug and piston kit.
It seemed to be of decent quality for a 60$ top end kit, home looked good, cylinder wall appeared to be round… I gapped the rings to the OEM spec and installed the top end kit.
I then installed a new plug, pulled the oil injection line off to rule out a non performing injection system and cleaned the carb very well.
At this time Still had the #70 jet and I even lowered the clip on the needle to second to bottom
To ensure good line for break in….
I filled the tank with 40:1 premix …
Broke bike in with 3/4 heat cycles on the stand ….
Seemed to run okay but def would not open up and rev out.
I adjusted the pilot to 2 3/8 turns out per Yamaha.
Bike still broke up a ton.
Pulled plug and it was black and wet …. Plenty of lube and fuel..
I then raised the clip back to 2nd down from top..
Had my son ride the bike around the house 5/6 times when he fell over the bike was running decent but not great.
He fell over and bike went to WOT and I ran over and picked it up and it said bahhhhhhhh and died.
Went to kick it and it was locked up.
I was very angry to say the least. 
I then rolled the bike down to the garage and tried to turn it over with my hand, one more time, and the engine was still locked up and would not kick over.
 got frustrated and put the bike away for the night as we were supposed to race our first race of the season the next day and I left it until Saturday afternoon.
My son wanted to ride something so I put him on the Stacy while I was screwing around with the PW and lo and behold now it turns over and is not locked up. 
Has anyone ever seen this happen before?
I don’t think it was Hydro locked because I pulled the plug out see photo and it looked reasonably Lean……
Is there much of a difference between the second clip up from the bottom on the needle and the second clip down from the top on the needle to lean the bike out to where it would get that hot and lock up especially with 41 premix in it?
I’m wondering if there’s something else going on possibly crank seals?.