markjs
XS400 owner, bike lover
Good point, I had not even thought of that!
-
Enjoy XS400.com? Consider making a donation to help support the site.
XS400.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
~Spoke too soon, spark box dying at higher revs on one side AGAIN!!!
- Thread starter markjs
- Start date
XSLeo
XS400 Junkie
On carb syncing, if your bike has or had vacumm petcocks syncing isn't hard to do. Go to the hardware store, get a rool of 3/16 clear hose usually 20 ft. A tard stick or any board that's about 3 feet long. Some brightly colored fluid. ATF works.
Now unroll the hose, hold the ends together and move along the hose holding the two sides, when you get to the end this will be the center of the hose. Put the center of the hose at the bottome of the board. Run the hose up both sides of the stick. I used clear packing tape to hold the hoses on the board.
Now put enough fluid in the hose so it fills each side of the hose about a foot to 18 inches up. You just made a very accurate manometer.
Now stand or hang the manometer close to the bike.
On the bike the carb holders have barbs were the petcocks get vacumm. Hook one end of the hose to each carb hloder vacumm port.
Now start the engine. If the fluid in the hose gets sucked up one side, then the sync is way off. Shut off the bike. Replace the fluid. Turn the sync screw a 1/4 turn one way.
Now try again. If the fluid still gets sucked up the same side you turned the screw the wrong way.
Shut it down and turn the sync screw the other way 1/2 turn Try again. Once you get the sync screw close enough the fluid will stay in the hose. It will bounce around some. but that's ok. Now very slowly turn the sync screw to get the fluid in the hose the same.
It can only take a very tiny turn of the screw to change the fluid levels by a bunch. Like 1/16 my change the fluid level by an inch. This proves how accurate this manometer is.
Once you get the levels equal your done.
On the bench sync Using the method described earlier will work, holding the carbs up to a bright light and adjusting to see the light in the gap the same works. Using a 1/4 inch wide strip of paper as a feeler gauge between the trottle plates and carb body works. All these methods get you close enough for the manometer to work.
Leo
Now unroll the hose, hold the ends together and move along the hose holding the two sides, when you get to the end this will be the center of the hose. Put the center of the hose at the bottome of the board. Run the hose up both sides of the stick. I used clear packing tape to hold the hoses on the board.
Now put enough fluid in the hose so it fills each side of the hose about a foot to 18 inches up. You just made a very accurate manometer.
Now stand or hang the manometer close to the bike.
On the bike the carb holders have barbs were the petcocks get vacumm. Hook one end of the hose to each carb hloder vacumm port.
Now start the engine. If the fluid in the hose gets sucked up one side, then the sync is way off. Shut off the bike. Replace the fluid. Turn the sync screw a 1/4 turn one way.
Now try again. If the fluid still gets sucked up the same side you turned the screw the wrong way.
Shut it down and turn the sync screw the other way 1/2 turn Try again. Once you get the sync screw close enough the fluid will stay in the hose. It will bounce around some. but that's ok. Now very slowly turn the sync screw to get the fluid in the hose the same.
It can only take a very tiny turn of the screw to change the fluid levels by a bunch. Like 1/16 my change the fluid level by an inch. This proves how accurate this manometer is.
Once you get the levels equal your done.
On the bench sync Using the method described earlier will work, holding the carbs up to a bright light and adjusting to see the light in the gap the same works. Using a 1/4 inch wide strip of paper as a feeler gauge between the trottle plates and carb body works. All these methods get you close enough for the manometer to work.
Leo
markjs
XS400 owner, bike lover
Excellent write up! Bravo sir and thank you!
