Decreased fuel efficiency

M

markf

Free Member

Oct 29, 2008

11

0

1

• Nov 29, 2008

• #1

Have a 2003 Summit 800 where the engine was rebuilt late last year (preventative maintenance). Since then, it runs through a tank at least 30% faster than before we rebuilt the engine. Very noticeable fuel consumption change. The plugs run a little on the wet side. I've checked for fuel leaks, and the carb settings were not changed, etc. Any ideas on why or where I should look?

 

S

sidehillsam

Active member

Lifetime Membership

Sep 24, 2008

159

31

28

Post Falls, Idaho

• Nov 29, 2008

• #2

Choke misadjusted & half on? A friend's Indy Trail was rebuilt and got crappy fuel economy. He eventually found a crack in fuel pump diaghram. ( Raw fuel sucked directly into crankcase.)

 

winter brew

Premium Member

Lifetime Membership

Nov 26, 2007

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LakeTapps, Wa.

• Nov 29, 2008

• #3

I agree....check the simple things, rerouting of the choke cable may have changed the free play? Make sure it has free play and no debris holding up on a plunger. Needle and seat worn?
Was the old engine pretty low on compression/worn out? Perhaps with the rebuild it is creating more vacuum and drawing more fuel through the same size jet? just a thought.

 

W

Winko

Free Member

Dec 2, 2007

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0

1

• Nov 29, 2008

• #4

Make sure all your DPM hoses are connected and in good condition.

 

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BackCountryBob

Well-known member

Aug 7, 2001

928

158

43

Arvada, Colorado

• Nov 29, 2008

• #5

Check you spring cap on the primary sliding disc. If it is original, the bushing might be worn cocking the disc.

BCB

 

M

markf

Free Member

Oct 29, 2008

11

0

1

• Nov 30, 2008

• #6

The original engine had good compression, and have checked the choke cable. I'll check the DPM hoses. And will check the fuel diaphragm. Not sure where the spring cap on the sliding disc is? Also heard a weak coil can cause more fuel consumption? Thanks for all the suggestions. Very strange. The engine runs great, but sucks the tank dry much, much faster now.

 

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BackCountryBob

Well-known member

Aug 7, 2001

928

158

43

Arvada, Colorado

• Dec 9, 2008

• #7

The spring cap is on your primary clutch. If the bushing is worn, it will **** the sliding half of the clutch and it will not let the clutch shift out (or in) keeping you in the wrong clutch ratio.

BCB

 

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BackCountryBob

Well-known member

Aug 7, 2001

928

158

43

Arvada, Colorado

• Dec 9, 2008

• #8

the word **** starts with a "c" and ends with a "k" and rhyms with "rock". This site is really getting serious

BCB