Question about Moto Guzzi Motorcycles

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Hi, my 1981 moto guzzi sp1000 backfires constantly. it seems to run smooth when I apply the choke. any ideas ? I have stripped the carbs cleaned them and set the float height.

I run the bike fairly frequently and the fuel is clean. I set the air screws to one and a half turns.

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  • Moto Guzzi Expert
  • 391 Answers

If both cylinders are involved then it has to be a fuel delivery problem or a timing problem. If you have checked the timing (valve and ignition) then it's fuel and it applies to both cylinders (I'm assuming here). The tank valve may be gummed up. Flow may be restricted.
If it isn't both cylinders then it will likely be a carb problem on the bad side. Go through that carb again.

Posted on Apr 13, 2014


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Posted on Jan 02, 2017

  • 66 Answers

SOURCE: 2003 yzf450 wont run right?

recheck pilot jet & pilot circuit.also check compression

Posted on Feb 16, 2009

  • 3567 Answers

SOURCE: 96 dr200 sittig up for 2 yrs. starving for fuel

Get some carb cleaner. Remove and clean the Nozzle, choke and main jet. Remove the pilot jet and air jet but count the number of turns to remove each one and put them back the same number of turns. Don't mess with the needle or clip or the pilot screw and plug at this time. Clean the carb thoroughly. Don't get carb cleaner on the diaphragm. If able, submerge the carb in cleaner overnight.
Let me know what happens by posting a comment.


Posted on Jun 27, 2009

  • 850 Answers

SOURCE: 1977 TS185 won't run smoothly; carb adjustment problems

thats the idle screw!
you need to adjust the mixture screw!

Posted on Aug 15, 2009

Testimonial: "Helped a little, still have problems :):("

  • 311 Answers

SOURCE: ltz 250 wont idle needs full choke to run.cleaned

hi,sounds to me like the air fuel ratio is all up the ***,locate the air/fuel screw on the carb(normally on the side)screw the screw right in untill it stops,then back the screw out 1.5 turns,this should get the bike to run without the choke,once you have the bike running simply turn the screw in or out untill the bike settles into a nice steady idle,should be good to go,hope this helps...cheers

Posted on Mar 27, 2010

  • 10 Answers

SOURCE: 2003 Suzuki Volusia 1,600 miles. Runs on choke

do you have a k and n air filter,or the like?

Posted on May 28, 2010

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Left carb backfiring thru carb after it warm up

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