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Have you considered having the gears, shafts, forks, fork shaft and drum isotrophic polished?

There are lots of places that offer this. It is not expensive, and IME the juice seems to be worth the squeeze. I have sent a few sets of transmission internals to Charlie. Cost was $165 plus return shipping. The parts returned looked fantastic. The gears and forks would slide much easier on their shafts, and the gears seemed, well smoother. Assembled and riding, the transmissions shifted much smother. R&D Transmissions claims this process frees up about 10% of power lost to friction. I dont know if that is accurate.

Like I said, there are others, but this is where I sent three sets. No issues.

Isotrophic Transmission Finishing

Final thought, If the gears are isotrophic finished prior to being back cut then the surfaces of the dogs and ears will not be polished. The issue with polishing the gears after being back cut is keeping the 2nd and 3rd gears straight as they are interchangeable until they are back cut. After being back cut, the 2nd and 3rd gears must be put back in their assigned places as they will be cut differently.
 

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Discussion Starter #1,002
Knew nothing about it actually. This gearset is in pretty good shape but not flawless. Only changing out first with andrews gears and the rest are all stock. I wouldn't want to go too crazy on this one. However by summer I'd like to build a another unit with a zip rack. That one I might consider sending out to try that. By then work should be kicking and would more feasible. Just trying to get this one more prepped for the abuse. This unit will become my back up if I should destroy the good one. My sons bike has same trans in his 93 FXR-P so we'd both have a spare. Last year he detonated his and put a Revtech 6 speed drop set in his. Who knows how that one will hold up. But he's only pushing 115hp
 

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Discussion Starter #1,003
OK so after some extensive searching for answers the plan is laid out and parts are coming in. Now I can get started on the transmission rebuild project. Got a baker complete rebuild kit, Andrews main and counter shafts, Andrews close ratio first gear set, S&S billet trapdoor kit, new shift fork shaft, Baker shift forks, Baker smooth shift roller drum assembly. Also got the new drive plate bearing for the toasted one in the Rivera belt drive. The trans is out and fully stripped to the bone on the bench. The building starts tomorrow. I had called zippers about back cutting and they didn't call back. Then called again and was told three weeks turn around... Not knocking them I know things are far from normal right now with this virus nonsense. I'm sure this was not the norm for them. Also after inspecting the gear dogs all looks very good. After researching this topic I deemed it not necessary. Worn out stuff and wrong adjustments being the main cause of popping out of gears. Went for the shift drum instead. Ordered new springs for the shifter pawl also. Decided to keep the standard pattern and skip the N-1 pattern. After thinking about it I use downshifting as extra brakes all the time. And would probably wind up at neutral not paying attention as it would be at bottom. So right around $1,500.00 in parts I should have a very solid performance gearbox for the bike.
 

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Discussion Starter #1,004
Got started on the transmission today and found some smashed up junk gear dogs. No point in building this thing with that crap. I live close to East Coast Super Bikes. They are a harley shop on the island. The owner is a cool guy known him for a while. He let me dig through a bunch of junk units and scraped up several replacement gears in pristine shape. So now all the gears are in excellent shape, a big score. Got all three replacement gears for 60 bucks. Got the gear set together and mounted on the door. New springs for shift pawl will be here tomorrow and I can get it back in the case. All is going well so far.
 

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Discussion Starter #1,007
Got the gearbox back together. All is well with the transmission gods. Painting it up tomorrow. Question... being there is two new gears and several others were changed out from different units. Also new forks, drum... Ect, should I run a load of 20-w50 motor oil in it and let everything break in before finally draining and going to Red line? Or just toss in the red-line. With how thick it is thought maybe thinner oil and let it all settle in first. Thoughts?
 

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Discussion Starter #1,010 (Edited)
Krikey! that's a beaut!!

Sent from my SM-G975U using Tapatalk
Thanks, should hold over 200hp safely now. Was nervous on hitting the nitrous when the dyno guy told me I was in the red with the stock trans. Last thing I need is the trans swallowing itself at speed and locking the rear wheel.... Un-fun
 

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Thanks, should hold over 200hp safely now. Was nervous on hitting the nitrous when the dyno guy told me I was in the red with the stock trans. Last thing I need is the trans swallowing itself at speed and locking the rear wheel.... Un-fun
FWIW BTDT at almost a buck and a half...10" drag slick too... Decidedly Not what I recognize as Fun!!!!!
Also Embarrassing how long you tie up/block the track whilst ya Break the chain... should had some big guys Carry the Damn Thing!!!!!
 

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Discussion Starter #1,012
FWIW BTDT at almost a buck and a half...10" drag slick too... Decidedly Not what I recognize as Fun!!!!!
Also Embarrassing how long you tie up/block the track whilst ya Break the chain... should had some big guys Carry the Damn Thing!!!!!
Somewhere around 1993 I had a 1980 Z1R1000 with a 1200cc drag motor. I dropped the clutch at Atco race track and to my surprise it hooked hard, I thought it would slip like it always did...... It didn't. I wound up going backwards through the air and bike when in the air and flipped out from under me.... ? Went two feet in the air bounced in a wheelie and fell on left side. Broke the alternator cover and leaked out all over the track. I landed on my knees going backwards behind the start line. I played it off by standing with my hands in the air... Got few chears... Embarrassing yes Lol.
Yes I would imagine a lockup is quite a pucker moment....at that speed thankfully you were OK. Damn. Crazy stuff. Racing is a dangerous game for sure
 

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Discussion Starter #1,013
Well this is harsh..... No bars open for two weeks so far in NY and no end in sight.... I can almost feel my liver growing back. There ain't squat to do and everybody is home. So I just went back to my shop. The only thing I can salvage out of this is getting the bike back together pretty quick. Plowing through it.
 

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Discussion Starter #1,014 (Edited)
Bike is just about finished and I'm getting to the extra stuff now. Now that the nitrous can fully go online, the problems have been resolved. The new heavy duty transmission, variable pressure plate clutch, new clutch pack, fork brace, and removed the compression releases. The one thing that I needed to do was was the throttle switch for the nitrous.
There are three safetys normaly run with a wet kit. As this bike is carbureted there is no fuel injection to add more fuel if it runs lean. So this bike has a dual output petcock, one line to gravity feed the carb and the second one feeds an onboard dedicated fuel pump

Fuel pressure switch: system shuts off if fuel pressure drops below limit. Lean means death to a nitrous motor

Window switch: this only allows the system to activate at set rpm and shuts it at just before redline rpm. In this case the window would be from 3000-6400 rpm. Hitting nitrous below 3000 rpm acts like you're putting in more nitrous and putts extreme stress on the pistons and crank. You'll either break the tire loose or break things.

Throttle switch: only allows system to operate at wide open throttle. If you cut throttle even a little the system shuts off. If you hit nitrous at part throttle the motor won't swallow it all all that explosive mixture can ignite and it will back fire hard enough to blow the entire carb assembly right off the bike in a big fireball .. Not good

Being that I'm only running a 40hp shot I'm only going for the throttle switch. I watch my guages well I actually mounted fuel pressure and nitrous pressure guages right next to tach when I designed the dashboard so I could monitor all three at a glance so i opted not to add the window switch or fuel switch. The throttle switch is must. Mounting it proved a challenge. There isn't allot of mounting points for a bracket in that area, it's just a little micro switch. I wound up filing the right side of carb to rough it up sanded the side of switch and used super strong epoxy to literally bond it to the side of carb and worked great. So that's done.
 

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One thing to watch out for... tho you have a Much better trans than the old 4-speed XL.. Note that lock-up clutch is Very hard on Trans gears when air Shifted... best to Unlock the clutch for shifts, and let it start over... Just Sayin
In case you Air Shift
 

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Discussion Starter #1,016
Yes it's hard on it. I had an air shifter on my old drag bike shifted nuts. Being that this isn't a track build but my everyday ride I'll not be putting one on this bike. I manually shift with full clutch. I can shift it really fast and I figure the three inch belt drive should at least give a little shock absorption. I set the the throttle switch with almost no end play. If you back off the throttle even the slightest it cuts the nitrous. it's wired in series with the handlebar button. When i shift I always back off the throttle a touch to unload the transband assist the shift. So the nitrous will cut out even if the button is still pushed and come right back online when I hammer it back to WOT. In theory it should all work well. It has a spark cut for rev limiting so even if I hit the limiter it shouldn't pose any damage risks or lean backfire. In theory anyway.... Lol
 

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Ohhh my Be Careful...cutting Ignition with WFO may result in overcharge of NOS... could Break ****!!!!

Always chasing worst case....
 

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Discussion Starter #1,018
I was under the impression that more modern bikes cut fuel to rev limit and that is huge problem as it goes lean at limit causing backfire and big booms. With a carb and wet shot and an ignition cut rev limiter it wouldn't be a problem. I'm under the understanding it should be able to safely hit limiter and it just won't fire that cylinder exhaust stroke should just evacuate the cylinder for next intake cycle..... Am I wrong? Would love to know now if this is off instead of later..... Ya know..... Lol
 

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I was under the impression that more modern bikes cut fuel to rev limit and that is huge problem as it goes lean at limit causing backfire and big booms. With a carb and wet shot and an ignition cut rev limiter it wouldn't be a problem. I'm under the understanding it should be able to safely hit limiter and it just won't fire that cylinder exhaust stroke should just evacuate the cylinder for next intake cycle..... Am I wrong? Would love to know now if this is off instead of later..... Ya know..... Lol
Depends on what ignition you use... for shifting Most simply turn back on wherever they are. the MSD only turns on on the Compression stroke I believe... bad JuJu... some research is necessary..
For rev limit I know the MSD turns off/on ignition at alternate Cylinders [obviously single fire] Some ignitions are indiscriminate on where they fire once RPMs are below limit... You can Hear the difference...after you have heard a few...
 

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Discussion Starter #1,020
I'm running the Dynatek 2000i setup believe it cuts every othe pulse alternating cylinders. But don't know exactly
 
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