9 miles

[mro]

Do ya know if the stock cams are 3H5 or 2H7?

unknown.........

At 1500 RPM, third gear will just putt along and can accelerate smoothly (not cranken it).

Engine has less vibration than a stocker too. Idle is a little lopey but when cold or warmed up will start immediately and idle at 11/1500. Choke (enricher circuit) pulls out (shaft travel) about half of stock carbs.

Clutch does not like to slip. Can let it out easy (normal start at a light) no problem, do same with rpm at 3/4K + and the amount of "slippage" is so small that it wants to pop the front wheel up. Plan to pull cover and check it after work today.

If I can swing it, would like to do dyno run with the cams in it now and them one with the others. Been thinking of hooking up the vac advance unit too although does not seem to be a problem cruising 50 to 70 MPH.

How much did you advance cam on there sprockets??? Intake and exhaust same amount???


mro

[79XS11F]

Originally posted by pggg
79, here's a good combination I had on my rebored bike - 1196cc, 80 valves, 78 carbs, 42.5 pilot jets, 142.5 main jets, 180 air jets, middle notch needle, floats at 25mm, carb slide holes drilled to 3mm, decent flowing 4-1, a K&N filter in the airbox, 8 - 10 holes 10mm in the airbox, a few holes in the snorkel too, hot coils like Dyna with no ballast resistor and non-resistor spark caps. Timing advanced 4 or 5 degrees, BP 7 or BP 8 sparkplugs. With a port job on the head I went up another size on the pilot jet and the main jet, the ported head gave a BIG kick of extra power, even with stock camshafts.

Did you port both the intake and exhaust?
Rob

[79XS11F]

My setup at this point in time is ... 1978 engine with 1179 kit, 1978 head with stock cams, Head is ported and polished on exhaust side only and the combustion chambers are polished. Good flowing 4 into 1 header, k&N in the box with 2 X 1.5 inch holes drilled in the box. Carb jetting is stock except the pilot jets which are now #145s, Dial -A -Jet system, Accel coils and leads, Plugs not chosen yet Timing will be stock to start.
Should I go with a cooler plug? Will this get the bike running safely with fine tuning getting done next year?
Rob

[MAXIMAN]

Rob

I went to a BP7ES plug (cooler).

MRO

I advanced the stock intake cam 5 degrees. It doesn't gain you a thing on top...actually you'll lose a couple ponies above 6 or 7 K. But it shifts the power curve down where the peak torqe occurs at 5000 instead of 6 or 7 K. It's a great move for getting low and mid range oomph!

The Web intake is dialed in per Webs spec. I think the cam lobe center is 108*. We didn't advance it. But then it really didn't need it. I gained so much torque and power over the entire rev range...but especially from 6000 to 9000 rpm.

[79XS11F]

Originally posted by MAXIMAN
Rob

I went to a BP7ES plug (cooler).

MRO

I advanced the stock intake cam 5 degrees. It doesn't gain you a thing on top...actually you'll lose a couple ponies above 6 or 7 K. But it shifts the power curve down where the peak torqe occurs at 5000 instead of 6 or 7 K. It's a great move for getting low and mid range oomph!

The Web intake is dialed in per Webs spec. I think the cam lobe center is 108*. We didn't advance it. But then it really didn't need it. I gained so much torque and power over the entire rev range...but especially from 6000 to 9000 rpm.

DAM I couldn't fine any BP7ES plugs so I went with a stock plugs.
Rob

[MAXIMAN]

Rob

Dunno about pggg but I had the intake ported ...not polished. He port matched the intake and exhaust ports to the intake boots and exhaust flanges.

However he took almost a full 16 oz cup of aluminum shavings material out of the intake of my head alone. We left it rough though for better bottom. Apparently if ya polish you'll gain top at the expense of the bottom end. Since Zilla is a big touring bike I needed the low end intact. It worked....see?

[79XS11F]

That looks GREAT. You have larger carbs installed ... right? My standard carbs were already a very good match to the boots and the boots a very good match to the head ports. The same was not true of the exhaust. The exhaust ports were very close to 38 of and inch smaller then the exhaust gaskets so I opted to only do the exhaust side. I matched them to the gaskets and opened up the whole port as far back as I dared go.
When I was running the engine earlier. I could feel the difference in the exhaust pressure and also feel the difference in the amount of air being sucked into the air box through the 2 X 1.5 inch holes I drilled in the bottom of the air box. If at any time in the future Ii put bigger carbs on this engine I will port the intake as well.
Rob

[MAXIMAN]

Yeah it has 36mm FJ1200 carbs. I really don't know how much difference they make because we never did an A-B comparo fo the 34 vs. the 36 carbs.

I know guys that have the stock 34mm carbs and are making at least as much power as I am. The 34mm Mikunis should easily feed a 100+ hp motor.