Kx250f No idle,lots of backfire.

K

Krossipoiss

Member

Oct 26, 2008

93

0

• Apr 10, 2011

• Thread starter
• #51

Back from track and with bad humor, as expected....
Now there's no/very little backfire and idle is pretty nice.
But while cruising with half throttle it just bogs/stomps.
Runs nice with a quater and accelerates also good+ runs good with full throttle.
Tried with 142,150 and 160main jet. Also all needle positions, but they didn't make any change..

 

K

Krossipoiss

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Oct 26, 2008

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• May 7, 2011

• Thread starter
• #52

New problem again- oil is at medium and with over half throttle it sprays out from Breather Hose. What could cause that ?
Piston has 2 hours on it.

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

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Merrillville,Indiana

• May 8, 2011

• #53

Excessive pressure from somewhere, or a partially blocked vent?

 

K

Krossipoiss

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Oct 26, 2008

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• May 9, 2011

• Thread starter
• #54

What could cause that pressure ? Worn crank bearings and seals ?

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• May 9, 2011

• #55

Krossipoiss said:

What could cause that pressure ? Worn crank bearings and seals ?

Click to expand...

Them also! I was thinking valve stem seals. And, fresh or not, the piston and rings?

 

K

Krossipoiss

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Oct 26, 2008

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• May 9, 2011

• Thread starter
• #56

Piston looks good and has max 2 hours on it. Rings set as wiseco manual told.
Stem seals are like new(worked for 1hour max)

 

Ol'89r

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Jan 27, 2000

6,958

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• May 13, 2011

• #57

Krossipoiss said:

New problem again- oil is at medium and with over half throttle it sprays out from Breather Hose. What could cause that ?
Piston has 2 hours on it.

Click to expand...

Possibly, upside down ring on piston or damaged oil ring from assembly. Did you make sure the marks on the rings were on top when you assembled the top end?

 

K

Krossipoiss

Member

Oct 26, 2008

93

0

• Jun 20, 2011

• Thread starter
• #58

Does sb know tps ohm settings ?