Schizoid, Power Arc, cam advance,

[wingless1]

That looks fantastic!!!

[ericheath]

I swapped jetting back to totally stock because my plugs were sooty with 140 and 70 main and primaries. Floats are closing ever so slightly ahead of the 21 mm mark. Runs better at speed, but farts like crazy when I let off the gas. I might toy with changing the vacuum signal to the cut-off valve, or enlarge the fuel line and fittings a little.

Performance is perplexing and probably due to incorrect mixtures at various rpms. Opinions welcome. I can come out of a side street, get fairly straight, give her the beans, and one time it gets up and goes, other times the backend gets loose and squirms around in a playful way. My guess is that at some rpm, the mixture is right or borderline lean, and makes good power, while other times it may be rich or lean but enough to lack power. Cruising speed is good. From 1800 rpm it pulls pretty well in road gear. The 77 cams in the 1000 are pretty gutless, but with the additional stroke of the 1200, it seems to pull fine.

I took it a 30 mile loop to check gas mileage- I know it's not enough but I wanted some idea. I seldom broke 60 and most was 45-55mph. Mileage was around 50. I think my best with the 1000 swingarm and final drive was about 38mpg and was usually around 30 in the city. So it appears the higher gearing will pay back soon.

Handling is bumpier in the back, but holds a straight line awesomely. I might be able to turn the monoshock down one notch still. The extra 3.5" length helps, and I have less twist in this swingarm than the 1000. It used to pull a little to the right. Now there's none. I have my windscreen to where it isn't a strong wing in my face. Cornering handling is fine.

[robin1731]

snip................. My guess is that at some rpm, the mixture is right or borderline lean, and makes good power, while other times it may be rich or lean but enough to lack power.

Best power for acceleration is with a slightly rich mixture. Lean will make it stumble.

.

[ericheath]

I have read quite a bit that say slightly lean makes more power, but is dangerous because it creates more heat. Playing with jetting and no AFR gauge is merely a wild guess with all the circuits of the 77 carbs. Getting the AFR correct across all rpm and loads would be lucky.

A lot of people knock CV carbs, but I'm starting to think they can be manipulated and re-jetting maybe isn't as important as getting the vacuum adjusted.

Best would be installing a wide band.

[HOTT]

Best power for acceleration is with a slightly rich mixture. Lean will make it stumble.

.

True dat!
Looks great eric !
Now how's about a shot NOT in front of the trash cans !!


HOTT

[82aspy]

Still needs a little filler before paint. Another oddity to this is how far left the rear tire sits, which I guess is common on 1200's...???

image.jpeg

I am going to do some measuring to make sure the two wheels are parallel to each other.

i have read the 1500 wheel swap to 1200 swingarm is supposed to center the tire better in that deal but jd said something about the stock 1200 swingarm swap to earlier frame combo setting the wheel off center, but didn't consider it an issue,

bike looks great luv to follow your efforts & progress

[ericheath]

HOTT, the pic wasn't planned for viewing, but the reflection of blue off the sky made it look cool, so I posted it. It just may be that the garbage cans make it look better than it is.

82aspy, I read also that it moves the wheel left. I had to push mine a long ways left for the ujoint to clear the swingarm housing. I just happened to be looking at mine before I came in to read this and like much of what I do, luck is a factor. The Magna front end I put on needed to be centred in the triples since the Magna triples are narrower. I chose to use one brake rotor and to do it, I moved the front left. It's always better to be lucky, (blessed for us Bible believers) than good.

I used an alignment check online and it involved plumb bobbing strings on each side of the wheels and then a string lengthwise around both tires.

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Mine touched both sides of the rear tire and had about 3/8" on each side of the front. I think they are very much inline. Using their formula I am maybe one degree out of plumb which, according to them, is good enough for race bikes. I wonder about it though, because the 'b' dimension was zero, and the 'c' was 3/8" each side. I have a 160 on the back and a 120 on the front.

Anyways it handles great. I haven't had it above 85mph yet.

[ericheath]

Chasing down my deceleration popping noises, I decided to try this:

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Since Schizoid was farting on decell like me when I've eaten--- well-- anything, yeah anything, I decided to reduce the hole which allows air when the cutoff valve is under vacuum. Left is JBWeld and a small hole, right is stock. Worked like a charm. I'll have to check it again in the heat this afternoon as they seem to be worse when hot, but I think I got it. My guess is each cylinder is pulling 50 cc's more vacuum and needs a bit more gas.

[ericheath]

Really like the PowerArc ignition. Good response on this bike at any rpm. I can lug it at 1500 rpm and not shift down and it responds well with no pinging. Of course shifting down is more fun, but if lazy and wanting to stay with traffic, you don't need to shift. The nice thing about it- and C5- is the advance is set by rpm. So even in the most advanced settings, the advance doesn't get somewhat advanced until around 2700 rpm. To reach the full advance of 42 degrees you're approaching 5000 rpm which with this final drive is probably 100 mph. I was initially worried about that much advance, but not any more.

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I wouldn't recommend my setup over the C5. I'm pretty sure the C5 off the cam is just as good and more easily bolted on.

[ericheath]

Still chasing perfection with carbs. This morning I think I got it right. Need to try it in the heat this afternoon.
Here's where I am for my hybrid:

764a carbs


7/25/16
Main. 120+. Air 70
Primary. 65. Air 135
Idle. 35. Air. 100

One Hole in bottom of slides JBWelded with 3/32 hole in it. (Smaller than stock)

No washer under the needles

One washer and it cackled on the way up and down.

Stock air jets were still too rich.

Next trial:
Might go back to 110 idle air jet next
Might bump up primary fuel (70) and air jets (140)

Running great. Hope to take my first long bike trip this summer to New Hampshire. Rear suspension is stiffer than I like. It would be nice to find a lighter monoshock for it that could be dropped in.

[robin1731]

Still chasing perfection with carbs. This morning I think I got it right. Need to try it in the heat this afternoon.
Here's where I am for my hybrid:

764a carbs


7/25/16
Main. 120+. Air 70
Primary. 65. Air 135
Idle. 35. Air. 100

One Hole in bottom of slides JBWelded with 3/32 hole in it. (Smaller than stock)

No washer under the needles

One washer and it cackled on the way up and down.

Stock air jets were still too rich.

Next trial:
Might go back to 110 idle air jet next
Might bump up primary fuel (70) and air jets (140) Doing this why? You pretty much cancel them out by making both bigger.

Running great. Hope to take my first long bike trip this summer to New Hampshire. Rear suspension is stiffer than I like. It would be nice to find a lighter monoshock for it that could be dropped in.

[ericheath]

I am thinking it could use some at 2-4000. Adding just fuel might make it rich again, but I will try it in steps. First the fuel jet, then, if needed the air jet. Easy to swap the air jet. Fuel- not so much.

It's actually good now. I'm going to cruise some like this and see how it does.

[ericheath]

It is running great again. I rode it off and on all day and it's great. Good take off power, squeals and goes sideways if too much. Accellerates to 8k easily, no backfires on deceleration. Now for some seat time.

[digschopper]

eric,did you rake the neck? looks kicked out a bit.

[ericheath]

Ala- HOTT's Here's Ol' Sparky build. Rides great.