Bender Twin Pipes & Silencers?

S

stv1991

New member
Found a used set of Bender Twin pipes for a vmax4. Any idea if these would be worth the $$? Twin pipes and comes with Bender silencers, states 10-12hp increase. Would I have to clutch and rejet for this combo? Just wondering if they are worth my time.

Robb
 

If you plan on putting them on an 800, then no, they are not worth the money. Bender Twins are no better than stock 800 twins as far as power gain. You will gain a little bit on a 750 and yes you will have to jet for it. If it is just a trail sled the stock clutching will be ok.
In my opinion if the pipes are nice and complete they are worth around 150 - 300 bucks.
Good Luck
 
Yes, they would be going on a 750. Will I still have a HP benefit if I run these through the stock can? As opposed to the twin Bender silencers? Noise to me is a factor, older i get, the less I like it. Lastly, I have a complete 800 pipe set Y to Can, instead of spending the $250 on the Benders would I be just as well off with the 800 set? Would here be any benefit of the Benders over the stock 800 setup? Weight maybe?

Thanks in advance.... Robb
 
800 set will do much the same job(9 claimed hp), can does nothing, stock will be fine with either setup. i dont think the weight difference between pipes would be much. bender can will be lighter than stock.
 
Do I change the Y's well or just the pipes? If this is the case, I should just use the stock 800 pipes I already have. Do I jet up one main? Or start at the stock mains since they are usually a touch rich from the factory.
 
you need 800 y's as well to achieve gains. stock 800 jetting is recommended but on mine(93) I simply used 140's for mains and 50's for pilots. It runs strong with this setup. I do wide open pulls all the time, for miles sometimes. I recommend doing plug chops at first to see where you stand. Not every motor is the same.
 
Thanks for the info. Mine is a 1993 as well. Looking at the parts diagram, it states Standard Pilots 47.5 and Mains 135. Are these mainjets the standard Mikuni hex or round jets for the mains? Reason why I ask is that www.PartsPitstop.com states that the 140's are no longer available and that seems like it couldn't be possible. I would think most any snowmobile dealership should have these Mains on hand. Would you agree??

This upgrade sounds like a good afternoon project for me next Friday...
 
FYI, lookup the main on a yamaha site. You will see sizes that only yamaha has (that I know of). That is the MJ's you going to fine tune with
 
Bender twins can run with stock 750 pipes. 800 pipes need 800 Y's. In Dynotech's pipe shootout (stock 93 engine 142 mains) stock pipes made 139.6 hp at 8250. Bender twins were at 151 at 8250. Silencer added nothing just sound. The sound on the Bender can is nice. Not obnoxious or overbearing for everyday riding. Gets real sweet out on a long stretch when up on the pipe. Weight savings is minimal Bender twins with can is maybe 6 (ish) lbs lighter than stock pipes/can.


You'll like them and will notice the difference. I ran mine (on trail) with 147 mains and 50 pilots on a stock 92 engine and it was never lean. We have another 92 here that has been worked up a bit and has had Bender twins on it for almost it's whole life (9300+miles). It's always had 135 mains and 50 pilots and has never had an issue. It has the ability to injest more air/fuel than a stocker though so I wouldn't jet that far down right away. 147's or 142's and see how things look from there.

One thing with the Bender twins is that you don't want to overrev. Power drops off quickly after 8250 and by the time you get to 8750 stock pipes are doing better. Stock pipes made the least HP but had the longest flatest curve of any pipe they tested (7 different pipes in total). PSI quads had the best overall improvement. HP met stock at 7500, peaked over 20hp higher at 8250 and was still 10 hp higher at 8750.

opsled
 
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