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hammondland

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Hey there everyone! I have an '86 Vmax that I am finally gonna restore. A few months ago I purchased every part NEW for the transmission listed for the transmission and I mean every part. I live in SoCal and now I am looking for a good gear man that can put it all together who specializes in Vmax's. Does anyone have someone they would recommend for me to go in SoCal?
 

one2dmax

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I can help but you didn't spend the money wisely. New gears don't address the mating issues that you have from production parts. I would still suggest an undercut to resolve that and give a solid trans that will shift smoother then a stock one ever could. This is not to say the new gears won't work but you just missed out on what you could have had (the undercut price is the same whether the gears are new or used).
 

hammondland

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well I got he the whole trans brand new because I wanted it fresh with no abuse, virgin to me. Ive heard about undercutting and the importance of it to make the trans work properly. I can only imagine what freight would cost to get the engine shipped to you Sean! LOL
I guess search continues to find someone here in SoCal. Thanks guys
 

mabdcmb@yahoo.com

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well I got he the whole trans brand new because I wanted it fresh with no abuse, virgin to me. Ive heard about undercutting and the importance of it to make the trans work properly. I can only imagine what freight would cost to get the engine shipped to you Sean! LOL
I guess search continues to find someone here in SoCal. Thanks guys
Open up the engine and pull the transmission yourself. Remove transmission and ship. Check this link. Its for a venture but the process on a vmax is nearly identical.
https://www.venturerider.org/forum/showthread.php?508-Second-Gear-Repair
 

one2dmax

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The trans work isn't all that bad. Shipped is about $200 each way so not too rude but I am sure you can handle it. The worst part is cleaning up the old gasket material.
 

one2dmax

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There is such a thing as "seasoning" when you talk performance OEM parts. That usually means whatever weak components, if any, would have shown up. Starting with 100% new parts and you could potentially have one of the rare bad parts (very rare). On the transmissions the OEM undercut simply was done for economy and speed of production.
 

hammondland

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Hey Sean, sorry for the late reply! Ok, now that I know the approximate shipping cost how much is your service for undercutting the gears?
 

LazyLiberty

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Hi Sean, what does the overdrive option include precisely? We are currently undertaking the tranny work, but I see your 'overdrive' popping up everywhere and can't seem to figure out exactly what the added benefit would be? Thanks for your time, Jonas.
 

Parminio

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Hi Sean, what does the overdrive option include precisely? We are currently undertaking the tranny work, but I see your 'overdrive' popping up everywhere and can't seem to figure out exactly what the added benefit would be? Thanks for your time, Jonas.
Curious about that myself. If it's a 6th gear I may have to start saving some bucks.
 

Fire-medic

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I think Sean's overdrive option changes the 4th and 5th gearsets to numerically-lower ratios from other Yamaha V-4 gearboxes. It's for more-relaxed cruising, lowering your rpm's.

No, no 6th gear. The bike makes 74 ft/lb torque, plenty to get you down the road. Think about what a 6th gear would require: a new set of gears, a new shift drum, shift forks, there isn't room in the gearbox for that. Many-gears are what low-torque, small-displacement bikes used to give them the ability to stay in their power zone. Look at the GP bikes of the 1960's/'70's, where they had up-to 18 gears, because their rpm range powerband was so-narrow. Honda famously had 22,000+ rpm engines for their small displacement roadracing bikes. Since small displacement engines don't produce much torque, their power comes from rpm's.

A Venture final drive (an easy mod) or the 4th/5th gear swap (case-splitting) is how to lower cruising rpms.

Some interesting reading on GP bikes from Honda's ascendancy.

One interesting point is their 1965 RC115 50cc two-stroke campaigned in Grand Prix had all-those gears (18!), while the next-year's four-stroke RC116 50cc engine made power across a wider powerband, and allowed them to use only a 9-speed gearbox. The four-stroke 50cc DOHC twin weighed a feathery 110 lbs dry. One way to go-fast is to lower power consumed by internal friction. You can imagine the difference gained there, from only having to rotate 9 gearsets compared-to 18 gearsets. An interesting confirmation of this, and Honda's drive for innovation pushing the boundaries of optimizing mechanical drag reduction, was seen in their 6 cyl Grand Prix engines, (one being the RC166, DOHC 250cc transverse inline-six cyl) where the crank bearings were different sizes for the journals, producing reductions in component weight, reducing friction, and minimizing the need for heavier components, as the loads imposed on the engine benefitted from the reduction in weight. Also, the package could be made-smaller, and less-aero drag is an easy way to make what horsepower you produce get you through the air faster, using the benefits of laminar flow. Here's an article highlighting the benefits of laminar flow, from today's aviation news:

RC166 Honda GP bike:

 
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one2dmax

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Ours swaps fifth gear only (with some additional undercut mods to the dogs to make it engage smoothly). It's a 23% reduction in RPM compared to stock. 1st through 4th remain the same which is where most of the play time takes place.
 

Fire-medic

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Sean must have been busy in the shop, making someone happy on a performance upgrade, to take that-long to answer. I was too-lazy to use the search function to find his prior posts about his system. I knew when he had the time, he'd set things straight.

To me, with the bike supposed to be good for 149 mph, stock gearing, I don't need to gain that kind of % reduction in 5th gear. I'm not using my bike as a transcontinental transit machine, w/a 120 mile range.
 

LazyLiberty

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Ours swaps fifth gear only (with some additional undercut mods to the dogs to make it engage smoothly). It's a 23% reduction in RPM compared to stock. 1st through 4th remain the same which is where most of the play time takes place.
Thank you Sean, first things first: get up close and personal with that case! As I am starting a new job this week, it doesn't look like she'll be out and about before winter anyway...
 

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