Matt_Hawk

Bought myself a kick-*** Superhawk last week and been dialing it in-

This worked VERY well:

Make yourself this carb. sync device.
It's among the best out there.

Items Needed:

1) Board 4-5 feet tall ( Mine was 5' ) - any scrap will do.
2) Clear tubing 3/16" ID x 5/16" OD x 20' long
3) One quart Stabil ( gas stabilizer )
4) Box of 15 electrical wire straps ( 3/8"- didn't have the ideal 5/16" ).
5) Some nails or screws 1/2" long with a good size head
6) Vacuum reducer fittings and caps ( 1/8" to 3/16" )

Home Depot- has the tubing, straps and nails for about $8
Autozone- has the vacuum fittings, caps and Stabil for about $14
Total was about $22.

Here's how to do it:

Make sure your bike is really warmed up and broken in- by riding her for 10 minutes:
( photo of mine connected was very noticeable before fully warm. Still it needed an adjustment as I was off. I never even knew ) This sync. is very sensitive.

1) Take the 20' tubing and mark the center. Then strap it to the board. You will have about 5'-6' of clear tubing coming out the top on each side if you use a 4' or 5' board. It's important to use 20' of tubing at an ID of 3/16". If you use smaller and shorter tubing, the thin fluid will be way too sensitive -due to vacuum that is way too strong from our 48mm Superman carbs.

2) Fill the 3/16" clear tube with Stabil. It's red, thin, and doesn't leave much residue on the tubing sides. You need to go 1/2 to 3/4 up the tube. If you use a low amount of fluid, it will pulse will the pressure changes. You can use an old cosmetic bottle from her bathroom. But I just put my mouth on one end and sucked a few times then held the end up over my head and let it drain.

3) Connect the 3/16" end of the vacuum fittings to the tubes. The other 1/8" end goes to your bike. Make sure BOTH ENDS are connected BEFORE you fire it up. If only one is connected you'll be sucking fluid in.

(This assumes you've already put equal length 1/8" vacuum tubes on each carb. port on your Superhawk. Front Carb- I used the carb port after I removed the Califonia Purge valve. Rear Carb- You will have to T-off the rear carb port leading to the vacuum fuel shut-off valve on the tank. When you do the sync, make sure you pull that line off and cap the exposed t-fitting. You don't want a vacuum leak.

Adjusting:

I used a 1/4" ratchet driver and a 1.5" extension with a 7mm socket to adjust the rear carb. balancing bolt on the left side. Just reach through the frame. This is important. A larger ratchet or longer or shorter extension will NOT give you the clearance you need to get to that tucked in bolt. The front carb. is the leading one and you don't need to touch it for this procedure.

There is no need to lift the tank. This works perfectly. This gauge is very sensitive- but does not "pulse" erratically. Only one ratchet tooth of movement from my snap-on ratchet made a difference when I was adjusting. The best thing is that if you suck some Stabil into the carbs then it's no big deal. Another cool thing is you can stand this Manometer against a wall and see it clearly. The 5' to 6' tubing ends give plenty of room to work. When you are done, cap the ends and put it in the garage.

Conclusion:

My idle came up about 150 rpm after I was adjusted perfectly. I reset it to 1200 and balanced again. Now it's perfect.
This thing PURRS like a kitten. It is smooth...way smooth pulling from a stoplight at low rpm. No more unwanted vibration at highway speed. The best thing is -this home made manometer is more sensitive than stuff I've used. You can control the sensitivity with the amount OR viscosity of the fluid used. If you want to save $8 then you can use any fluid. I wanted Stabil for security. I used about a third and can use the rest in cars this Winter.

Note: When you disconnect the vacuum tank shut-off valve line from the rear carb and cap the T fitting, you will only have about 2 minutes of fuel in the carb. bowls to do your business. Then you're out.

One trick is before you pull that line while the bike is running, pinch it hard with your fingers- then put a capped fitting in the end before you release it. This "tricks" the fuel cut-off valve into thinking the bike is still running as you have trapped negative pressure in that line. Take your time now.

-Matt

sam

Very nice, thanks for the pics. I think I'll try that come spring time, it's almost time to put it away for the year here.

98VTRrider

nice write up..might give that a try

KCCO