1st Gen V-Max primer on Carb "stages"

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Joined
Jun 25, 2023
Messages
41
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Location
Oklahoma
VMax Year
98
looking for a basic primer on "carb stage" mods. I read a lot about stage 1, stage 3 and stage 7 mods. are these just kits marketed by one particular company? Or, is there a technical meaning behind the different stages.

I have two Gen 1 Vmax, the 2002 is stock and staying such. but the 98 is one Im willing to play with an mod for fun. trying to figure out what I want to do, but also what the terms I read about mean.

thanks.
 
There is no S3 for a Max and S1 & 7 are Dynojet nomenclature for their kits.

Attached are the fitting instructions for both kits.

I've no experience of either but from what I've read S1 doesn't seem to have many (any?) fans whereas S7 does have some takers and no doubt they will chip in with their experiences.
This is a quote from this seller "The Dynojet Stage 7 Jet Kit is a great tuning option when upgrading to a full aftermarket exhaust system on your 1985-2007 Yamaha Vmax. Dynojet Jet Kits increase power and smoothness throughout the entire rev range, while maintaining optimum fuel economy. Stage 7 Jet Kit requires running four individual K&N pod style filters, available separately."
Note the comment regarding the exhaust and filter requirements...no one ever said getting more power was cheap!

You can also get some thoughts from the Forum here

A third option is the Morley jet kit, referred to in the thread link above.
 

Attachments

  • Dynojet Stage 1.pdf
    2.9 MB · Views: 0
  • Dynojet Stage 7.pdf
    134.3 KB · Views: 1
The stage 7 kit tends to favor performance gains at the top of the rpm range. Sean’s kit including air box mods favors lower and mid range power gains. I run Sean’s kit and my best friend Steve o runs stage 7. I prefer Sean’s kit as I don’t often run at 9000 rpm for long but I sure do blast around between 5000 and 10,000 rpm every time I ride.
 
I sure do blast around between 5000 and 10,000 rpm every time I ride.
If you don't have one, an ignition box w/a rev-limiter will help your engine to live longer. Running our bikes at 10,000 rpm isn't conducive to keeping it healthy, especially if you miss a gear at that upper-end.

I believe at one point the factory dropped the redline a bit in the interests of promoting engine longevity. It has no rev-limiter in the OEM ignition unit.

Max Midnight has provided you with much of what you need to know. I use a 147.5 main jet, and Stage 7 needles & other mods, w/a 4/1 UFO, w/a custom canister from a 1000cc sportbike. The sound is much-reduced from the Kerker 'competition baffle' or UFO Dragstar end of exhaust noisemaker, and the bike also has a DYNA old-style (dip-switch) ignition box, w/its rev-limiter.
 
thanks gents ... after I figure out what shape the 98 is in ... and anticipating the carbs may need work, am thinking about "if Im already going to have to fix the carbs, maybe I would want to add special sauce". so now I have some understanding to work with :)
 
Probably the most important thing to remember is that for the bike to make more power with some bolt-ons, that means additions to the intake side and the exhaust side. The exhaust side is a full exhaust, w/larger headers and less restriction on the canister(s). If you don't run a full exhaust, it's not going to make more power.

The Dynojet Stage 7 is what a lot of guys use, but you have to tune it with the jets to get the best results. Sean Morley's Muscle kit is going to provide you with a better overall performance for the type of riding most riders use their bikes for. There's also the Factory Pro set available. I don't have info on those, other than the fellow who developed it has done well with Yamahas.

If you have access to an ultrasonic cleaner, that's the method I recommend to make things work from a thorough cleaning. If your carbs are just filthy, I suggest ultrasonic cleaning, and some fine wire like a guitar string to chase all the passages, then blowing them out, and throwing carb cleaner into them after using the wire, to show that they flow through their passages as they should.

Don't forget the air cleaner, it should be clean also.

All of this isn't going to do much for you if the gas tank is corroded, even with a filter. Cleaned carburetors will soon become obstructed from rust. You have to make it all operate properly.
 
Probably the most important thing to remember is that for the bike to make more power with some bolt-ons, that means additions to the intake side and the exhaust side. The exhaust side is a full exhaust, w/larger headers and less restriction on the canister(s). If you don't run a full exhaust, it's not going to make more power.

The Dynojet Stage 7 is what a lot of guys use, but you have to tune it with the jets to get the best results. Sean Morley's Muscle kit is going to provide you with a better overall performance for the type of riding most riders use their bikes for. There's also the Factory Pro set available. I don't have info on those, other than the fellow who developed it has done well with Yamahas.

If you have access to an ultrasonic cleaner, that's the method I recommend to make things work from a thorough cleaning. If your carbs are just filthy, I suggest ultrasonic cleaning, and some fine wire like a guitar string to chase all the passages, then blowing them out, and throwing carb cleaner into them after using the wire, to show that they flow through their passages as they should.

Don't forget the air cleaner, it should be clean also.

All of this isn't going to do much for you if the gas tank is corroded, even with a filter. Cleaned carburetors will soon become obstructed from rust. You have to make it all operate properly.
FM -- that is really great advice I probably would not have put togeather. thank you very much. I don't plan to do any crazy riding, but just playing with it at this point. More of my engineering background curiosity to optimize, even if not planning to stress test it :)
 
I bought a parts bike w/title from a mechanical engineer who was a alumnus of my alma mater. He had so-many projects at his home, I got a mostly complete bike, but missing a few things, for very cheap. I haven't been able to get anywhere w/it, but I did rescue it from outside storage, and place it into dry storage. He had plans for adding a turbo, but besides removing the exhaust, he never did anything.
 
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