Noob rebuild and questions

[blaster_rider11]

Hey guys, i have been on the forums for a bit but havent posted just read and picked up some knowledge from you guys. i have a Blaster with a Vito's 240 top end kit. I bought the quad from FL and relocated to Albuquerque, NM(5500ft elevation) I was riding here whenthe quad shut off on me and would not start. i tried cleaning the spark plug, new spark plug, compression test, switching fuel, cleaning carb. Nothing worked. i opened up the top end to find that the rings were fried into the piston. i have a 320 main jet and a 30 pilot jet. wha could have caused this? What can i do to prevent this again? I also have K&N air filter(no lid), vforce 3 reeds, Vitos fatty pipe and silencer, vitos adjustable stator. Hope to hear from you guys soon. thanks.

 

[Blaaster]

Without seeing the condition of the crown of the piston I would suspect lack of lubrication.

 

[1995blaster]

What was the adjustable stator plate set on? and what fuel was it properly mixed with the right oil?

Did you do a plug chop or a leakdown test?

 

[blaster_rider11]

Leakdown test was good as well. I mixed Yamalube 2r oil with 87. I havent gotten to the stator plate. What could be the issue with the stator plate to do this? Spark plug was black out when i pulled it. What the previous owner told me, he suppposedly did a good break in but the kit was new with 4 hrs tops of riding.

 

[JWjite]

I think you probably should have rejetted the carb, I think that is what coused you to fry the topend 5500ft elavation is a rar cry from floridas measly elavation. I am no profesional but I am sure you need to rejet the carb for different elavations.

 

[Blaaster]

What does the top of the piston look like, is it smooth, or is it rough and pitted.

 

[Awk08]

forget what the dude in florida told you, sounds like bullshit to me

yes, you do need to rejet for elevation....the other direction
sea level calls for larger jetting than 5500 ft.
and who installed a 30 pilot in a stock carb ????? thats too small for even a stock bike, which comes with a 32.5 pilot jet which will handle most set-ups that a stock carb will
not sure, but there isnt many peeps on here running a stock carb with a 240 kit, which a 320 is too small for that cylinder/pipe combo
i was running a 320 in my stock carb/stock cylinder with just an f7 pipe/vf3's/uni filter, when i got it ported i jumped to a 34mm carb

if you don't get a bigger carb, (34/35mm) < highly recommended
at least put the 32.5 or a 35 pilot in it, and start with the biggest main jets you can find and work down, i'm almost positive proper plug chops will show that 320 main is way too small for what you have, as is that pilot jet

so yes, lack of lubication, and fuel in general, which cools the cylinder, from way too small of carb/jetting caused that

 

[FLOTEK]

a lean pilot will never make your bike seize like that,the jetting doesnt sound real far off if there was no air leak and it was lubricated my guess would be it was ran for extened time at WOT got very hot and had a seizure

 

[blaster_rider11]

hey guys I appreciate the help so far. When i did ride i was WOT more than a handful of times but never more than 10 secs being afraid of exactly what happened. the cylinder itself is in good condition jus the piston with scores on the exhaust side and fried on top. Here is a picture of that,

What would you guys recommend be my next move? I am going to buy another piston and ring set and step up to big jets for the time being. What is everyone's opinion on getting my ride riding again?! Thanks for the help so far.

 

[Awk08]

i'd have that cylinder measured to be sure it's within .003-.004 maximum larger than the piston, if it is beyond those specs now, next larger size piston and a bore job will be required

 

[Blaaster]

Thanks for the pic, a picture paints a thousand words!

Overheated possibly by WOT but more likely by too lean a mix. Possibly most the carnage happened before you picked up the bike and your WOT on a relative new rebuild finished it off. New piston, rings, may get away with just a hone. .. . Proper break in and diagnostics and your laughin!

Your jetting seems ok to me ,but I would take the main up one to more on the safe side for break in, can always bring it back

 

[blaster_rider11]

So is 32:1 for premix good for this area or should i change that up as well?

 

[Blaaster]

32:1 is good for you unless you plan to punish your engine.

 

[JWjite]

Ya dude forget what I told you it doesnt look like jetting could do that to your piston.

 

[blaster_rider11]

Im gonna go ahead and get the cylinder checked and get a new piston in there. Forgot to mention the plug that it was riding on was a B7ES which if i am correct is a hotter plug. I think that led to the detonationplus the crappy 87 oct gas here.

 

[Larry's Shee]

Best to include these "little" details from jump street. Hotter plug and hotter burning fuel in NM where it's real hot , maybe (?) cheap oil.

 

[blaster_rider11]

Yea completely slipped my mind. Also theoil i used was Yamalube 2r. what would be the best replacement plug for riding for this area?

 

[Larry's Shee]

Br8 range. By chance did you do leak down before you tore it apart? Premix or injection? Piston looks a little worse than my son's, jetted for about 20* f , was riding WFO
on the ice at about -10*, don't know if it went to lean or oil was to thick.
I would only run premium, unless it's a major name brand regular , they can do too much weird sh*t with regular gas, cutting it with paint thinner, rafenate, things like that.

 

[Blaaster]

Stick with the B8es plug it is the recommended heat range, nothing will be gained by using a BR8es as the R series is a resistor plug designed to stop interference to radios and such like.

 

[shadow04]

I rebuild my motor and it feels hestiant at lower rpm. Is that normal or do I need to put a bigger size jet or smaller