Tuesday, August 20, 2013

SYNCHRONIZE CARBS.

I made a carb stick out of 12ft. of 1/4" clear tubing, some ATF and a 2x2. My engine had vacuum ports already threaded into the manifolds so I just had to make barb fittings to fit. I used 2 bolts that fir the threads and drilled a hole down the center and machined the head off.


Check the throttle slides with some drill bits till you find on that just slides under the throttle slide. Get both carbs as close as possible to prevent sucking all the ATF into one cylinder. It won't hurt the engine if you do, it just takes time to fill the tube again.

The trick is to get the liquid even in the tube at idle and then to stay that way when throttling up. Adjust the cable fittings on top of the carb to do this. At idle if the oil is high on one side that means that side has the throttle slide too low so screw in on the idle speed screw or screw out on the other carb. When throttling up if one carb has high oil it is opening less than the other side so screw out on its cable adjuster. This works really well and works just as well on 4 carbs. Just use 4 tubes all tee fitted together at the bottom.

Here is a video showing how it worked.





Friday, August 16, 2013

TRAILER

I had a 5' X 10' utility trailer so I modified it to hold the JZR. It took a lot of cutting and welding of old parts and adding some new 3" angle. I got a 2000# winch at Harbor Freight for 50 bucks on sale and another 50 bucks for the #6 battery cable and disconnect to go up to the truck battery at NAPA. I was a bit worried about tongue weight with the front of the car behind the trailer wheel but it worked out well and when I add the trailer spare tire to the front that will make it even better. Still have to put the lights back on somewhere and some paint to finish it up. Now I can load up and take it somewhere to do more driving tests, that is if it ever stops raining. It is like the monsoon season here.





Wednesday, August 7, 2013

TACH AND SPEEDO

When I first cranked it up I noticed the electronic tachometer was hardly moving off zero. After much thought I came to the conclusion that with dual points and coils the tach was getting one pulse per two revolutions of the crank. The tach thinks it is setup for a two cyl. engine and should get 2 pulses per 2 revolutions of the crank. I was advised on the Yahoo Replicas forum to add 2 diodes to the coils so that the tach would get the 2 pulses it needed without causing the other coil to fire when it wasn't supposed to. Thanks David. The pic should show how it's done. I'll neaten it up with shrink wrap tubes later.

The next issue was getting the electronic speedometer working. These use a pulse generator that fastens onto the tranny where the speedo cable was attached. With the Guzzi metric threads I could not find a pulse generator to fit so Classic Instruments fixed me up with a magnetic pulse sensor. This is mounted on the front upright and counts the spokes on the brake rotor. This seems to work when I spin the wheel by hand. I'll have to go through their setup procedure to calibrate it.

I paid $85.00 for the sensor. Do a search for "cherry gs1007" and you can find one for 30 bucks.

UPDATE: June, 2014
I burned out 2 of these units before I realized I had bundled the wires next to the spark plug wire. It looks like voltage spikes were getting into the sender and causing it to fail.