ramping the fingers 62t

waxhead

wannabe backflipper
Location
gold coast
Just because they sell it doesn't mean it actually works. Sometimes they just make things to sell. Create a market. Remember the blowsion carbon air filter
 

waxhead

wannabe backflipper
Location
gold coast
No I think it was because groupk said they were a good thing years ago and so every one was wanting to run them. R&d made them because they were losing sales. Some as the big bores. Dan lamey didn't want to do it because he knows it's not technically right for a two stroke. But he had to release it as he was losing sales
These business are in the market to make money or at best to not lose money
 
Location
Ohio
Zero proof that they helped in any setup?

LOL this is kinda how I feel about porting! The same results can be achieved via a prop or a pump tune! Right?

The ported motors I have tried drank more gas and hit the same!
 
Location
Ohio
I was kinda messin... The port jobs I have ridden were on skis that were clearly not tuned at the pump.

Someday I'll get mine ported and do back to back.

It just seems like at the end of the day...the pump is key to everything....IMO.
 

waxhead

wannabe backflipper
Location
gold coast
Yeah your right on the pump. The jet unit is about 60% efficient. Any time you can pick up efficiency there your on a win. The jet sprint guys will say 1% pump gain is equal to 10% engine power
 
i do run them in my ski along with case stuffer and they work great and i have built 3 other motors with the same set up and they all ran good
 
Isn't crankcase compression ratio needed for a 2-stroke engine to run? What happens when we have broken reeds? (Major power loss, piston can no longer effectively displace the air below it). The scavenging of the air fuel mixture is depending on the volume in the crankcase among other things. When the piston is at it's downstroke, there is positive pressure in the crankcase that closes the reeds and the actual downstroke of the piston displaces the air in the crankcase into the cylinder.

I don't think reed stuffers or filling the fingers do much to the velocity of air entering the crankcase, but it's reducing the volume in the crankcase so the down stroke of the piston can more easily displace the air in the crankcase. At least thats what I think the idea of it is. I have no experience with reed stuffers, but I think they are a tuning item much like a shorty pump cone. Either it's going to work or it's not. Luckily it's a non-permanent modification.

I did read somewhere, and I do believe it to be true, that the fingers on the yamaha cases are designed to aid in lubrication. Oil gets trapped between those fingers.
 

SUPERJET-113

GASKETS FOR CHAMP BRAP!
Site Supporter
My $.02 is that stuffers work well on smaller displacement motors like a 250 two stroke MX motor, thats why they use them. If they are so all around great, why didnt Yamaha put them in their watercraft engines? Also, you would think PWC engine builders of our time would recommend them for their engines if they were so great??

OK, so now with reed stuffers you are running a much smaller opening for the intake charge to go through. Sure, it speeds up the charge, can give a better carb signal, and can give a bit better low RPM throttle response, but hit mid and top RPM's and its a choke on PWC engines...

IMO, spend your money on good set of Vforce reeds and a A/M manifold and your set!
 
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waxhead

wannabe backflipper
Location
gold coast
I dont normally right technical stuff n here anymore because of the stupidity that happens when people don't understand it.
But lets give it a go
First you have to remember that air has mass but unlike a liquid it can be compressed. So when the reed shuts the air rushing up behind it has to go some where. with a reed stuffer there is no where for it to go. with out the reed stuffer there i a small area for the higher mass air to collect. due to the now mismatch in the reed versus manifold the air is more resistant to flowing back up the intake tract. This has a slightly higher than normal pressure sitting at the reeds waiting for them to open.
By putting in a reed stuffer you take away this. I have done it on 50cc jetskis mx bikes and even a gp125 motorbike and it was a gain on all of them.
Why do they do it from factory ? simple every one was doing it at the time it was though to be better. they also used to stuff the crank cases as well to try and make more power now they open them up as much as they can.
 
Don't Vforce reeds come with plastic stuffer's? They are not tied to any one brand. They are strictly an aftermarket go fast company trying to convince us to ante up for a few potential ponies and maybe better throttle response over stock rite? Why do you think they include them if they don't help the reed petals pull harder on the main jet during the rise of the piston? I have to believe they have tested their product every way you could measure. If they didn't show an improvement in flow why waste money on their end producing and including them in the set?
I have more experience with higher rpm 2 stroke sled engines than 7200 rpm ski motors and can tell you this. I have watched Dyno numbers go up with them in consistently and down with them out.
I am sure Wax that what you experienced happened with the motors you were building. Soooo many pieces of the puzzle with a two stroke that make them all unique it is hard to say yes or no in every instance. Easy to try to see if your motor responds better or not. Heck I believe in them from my experience and have the Protec stuffers and pre-filters on my decked n ported WDK 927 and it rips. I had no intention of pulling either off the motor before I read this thread. Just because I respect yours and other peoples experience I am going to and see if it picks up......maybe?:)


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