Non Starting Xr400

[PAULOS]

Hi Folks

I Am Wondering If Anyone Can Help

I Recently Had The Displeasure Of Blowing The Piston In My 2002 Xr400.knowing This Was Going To Cost Me Anyway I Thought I'd Take The Opportunity And Bore Up,so I Bought A Wiseco 440 11-1 Kit And Also A Set Of Bronco Magnesium Valves.

I Had It All Machined,put It Back Together And It Fired Pretty Much Straight Away But Would Not Run.i Eventually Got It Running But It Ran Quite Rough/uneven.i Only Ran It For A Very Short While And Just Took A Ride To The End Of The Road And Back,it Had Plenty Of Power.the Wife Was On My Case So I Had To Put It Away

The Mext Morning I Thought I'd Change The Plug And Lead.it Has'nt Run Since

I Hvae Kicked It So Much It Is Probebly Run In And I've Started To Walk Like John Wayne

I Took It On A Trailer Up And Down A Big Hill To Bump Start It .in Second With Throttle It Would Fire,flip A Wheely,die,fire,flip A Wheely,die,fire,flip A Wheely,die And Was Like Being On A Bucking Bronco But Would Just Not Run

I Think I Have Checked Everything At Least Twice.the Only Things I Have Concern About Is The Valve Timing It Lines Up Ok Without The Tensioner But Is Not Exact With The Tensioner.i Am Fearing That The Timing Chain Jumped A Tooth On The Crank When It Was Apart But I Have Had A Good Look At This And It Does'nt Seem Possible

Iv'e Changed The Plug Twice And The Lead,stripped And Cleaned The Carb Twice,i Seem To Have A Good Spark .fuels Getting Through,i'm Just Not 100% The Timing Marks Are Right But It Seemed To Much Power In The Few Minutes I Rode It To Be That
The Only Other Thing Is The Piston Broke Up And Debris Got Into The Stators And Flywheel But I Have Got A Good Spark

I Am At A Loose End With It Now And Before I Strip It Right Back Down And Start Again I Thought I Would Ask The Question,particulary The Timing Set Up,does It Line Up When Tensioned And Is Ther A Chance It Can Move Off The Bottom Cog

Any Advise At This Stage Will Be Greatly Appreciated.

 

[Hughes 097]

jett the carb and is the stock seliencer on your bike if so take it out so its a gaint gapping whole like mine because stock it has that quarter of and inch whole real tiny not much room to breathe and if not put a pipe on it prefferble a whitebros

 

[sixds]

jett the carb and is the stock seliencer on your bike if so take it out so its a gaint gapping whole like mine because stock it has that quarter of and inch whole real tiny not much room to breathe and if not put a pipe on it prefferble a whitebros

i dont think it could be jetting, as it happened after the rebuild. but you could have got something lodged in your carb while rebuilding it. try to clean out all the passages of the carb and see if that works.

 

[_JOE_]

What does your service manual say about timing?

 

[Dracus124]

Try resetting the valves, you should always check the valves after a rebuild, unless its a 2 stroke, check the reed vavle if its a 2

 

[Dracus124]

Is the air filter wet?