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Carb sync

Started by Thmsdoyle, May 01, 2013, 07:57:46 PM

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Thmsdoyle

Ok after reading many post on carb problems I decided to go ahead and dive into them. I too had some hesitation just off idle, some vibration at 3500 rpms to 6000 rpms. I'm sure it was still there at higher rpms but not as noticeable.
Carbs #1 was at 17 hg, #2 at 6 hg, #3 at 4hg, #4 at 11 hg, and it still ran fairly well getting 39 to 42 mpg depending on my mood. Adjusted all to specs per Haynes manual. When I synced 1&2 to 3&4 my idle started to to raise up to 3300 rpms, adjusted it down and continued to synch. Again a second time I had to adjust rpms down from 3000. But this time I was with in the hg difference of .4 hg.
After the synch I opened up the pilot screws a full turn do to a recent post on off idle hesitation. Test was good, vibration through out the rpm range is pretty much gone, hesitation is just barley noticeable. So maybe another half turn on the pilot. I was also getting high rpms after running a while when engine was good and hot. That too has been resolved. Overall much improved. We continue to move forward, the fj may look a little worn but she runs very well.
Tommy D.

fj11.5

Nice work mate,just in time for summer kookaloo :good2:
unless you ride bikes, I mean really ride bikes, then you just won't get it

84 Fj1100  effie , with mods
( 88 ) Fj 1200  fairly standard , + blue spots
84 Fj1100 absolutely stock standard, now more stock , fitted with Fj12 twin system , no rusted headers for this felicity jayne

movenon

Good on you ! A little tuning makes her happy  :rofl:.
I checked the valves and did the same yesterday. I was in good shape but it pays to check for a piece of mind. Today I did a little surgery on my air to fix some of the problems I don't like about the box. Possably UniPods someday..
George
Life isn't about having the best, but about making the best of what you have...

1990 FJ 1200

yamaha fj rider

The better sync you can get, the smother it will run. This is one of those places that you should just take your time.

Kurt
93 FJ1200
FJ 09
YZ250X I still love 2 strokes
Tenere 700
FJR1300ES