Carb syncing

[JonnyWyshbone]

yeah dude i fixed her but it got worse before better, my cylinders were flooded with gas at one point... all fixed now and in the end i ended up learning a lot

I know what u mean, nothing good is ever easy for some reason So based on GateKeepers post about the location of the master carb, and based on the vid some idiot(me,lol) posted that indicated the same thing, don't ask me why I came away from it thinking it was the one with the throttle sensor. I decided that I would redo the sync since I used the wrong carb to sync the gauge. As u know I did a sync last week, so I went back in and adjusted the gauge properly on the master and ran the check. Also seated the pilot screws and brought them back out 3 turns just so I know it's been done proper. From the last sync, this is what my carbs were reading this week I know it's said that newer bikes are supposed to hold their syncs longer, but what about a fairly new bike based on an older one? Anyways so I also decided to see if there was a difference in having the airbox on and off for the sync, here's with box off and on in that order so a bit of a difference. I managed to get everything sorted and straight, I'm not putting myself through this again for at least another month to see if the carbs keep their setting but here's proof that everything was as even as I could get it before putting her back together and before I forget, contrary to what some of you mofo's put in your post, there wasn't s**t about that fun!! Lies make baby Jesus cry and all that, lol

 

[theraymondguy]

and before I forget, contrary to what some of you mofo's put in your post, there wasn't ****** about that fun!! Lies make baby Jesus cry and all that, lol

Aaaaannd that's why I like thumpers.

Older bikes will have trouble holding their sync due to worn carb components (hardened o-rings, intake boots etc.). Little leaks can add up to big problems.

 

[Redrock]

Good post guys, lots of good advice for someone new to wrenching carbs.

 

[Stewart]

I asked the same question early in my apprenticeship.

Compression values supplied by manufacturers / clymer / haynes are always supplied assuming that multiple cylinder engines have the spark plugs installed. For their values to be of any use, we also must test consistently.

Typical cranking speed for a gasoline engine is roughly 4-600 rpm (depending on starter type, battery strength). If the crank is allowed to 'freewheel' (all plugs removed), engine rpm will be much higher (nearly double) than if the plugs are installed. This can disguise low compression (if you have blow by due to worn rings/piston/polished cylinder, which could easily be a consistent fault in each cylinder).

Also, starter motors are series wound motors. Unlike parallel or shunt wound motors, they have no means of limiting overspeed. Running a series wound motor at high rpm (cranking starter while battery is on a charger) without a load on it (spark plugs removed) can cause the commutator segments to separate from the armature and scatter the brush gear all over the shop floor... and ceiling :confused2:

you forgot to mention the best test ...the leak down test or even the dry and wet compression test. great for trouble shooting with out surgry.