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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> 25T Pulley Installation /cgi-bin/YaBB.pl?num=1675564067 Message started by DragBikeMike on 02/04/23 at 18:27:47 |
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Title: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:27:47 I installed one of Dave’s 25T pulleys back in September of 2022. It was a significant change. Rather than machine the back side of the pulley, Dave suggested that I could shorten the pulley spacer. I thought that might be a good approach, so I agreed. The installation was easy but there were a few small details to iron out. Seems like a good candidate for a report. Previously, Dave would machine the backside of the pulley to achieve correct belt alignment and to allow the splines on the output shaft to engage the lock washer. Should be able to shorten the spacer and achieve the same outcome. I had to trim the spacer exactly .200”. That should place the centerline of the new pulley in the same location as the stock pulley. If you use this method, make sure to remove the material from the side of the spacer without notches. The notches are oil passages. Remove them and the output shaft will not receive any oil. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:28:36 The spacers are tough. Look at those blue chips. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:29:22 When I installed the spacer and tried to fit up the pulley, the pulley would not go all the way home. The sharp corners on the female splines bottomed out in the roots of the male splines. A minor setback. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:30:41 With the stock spacer, the root of the splines isn’t exposed, so the female splines in the pulley never come close to the roots of the male splines. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:31:42 That was easy to fix. Just machine a 35° chamfer on the female splines in the pulley. The face of the pulley must bear hard against the spacer. The chamfer eliminates the spline interference and allows the pulley to go all the way home. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:32:24 This shows the chamfer. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:33:06 The splines on the output shaft must protrude a bit for the lock washer to engage. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:33:45 The lower belt guard must be checked for interference. Very important if you have longer rear shocks. Raise the rear of the bike until the rear tire is off the ground. The swingarm must be hanging on the shocks. Make sure the belt guard has ample clearance. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:34:28 The pully cover boss on the engine case interferes with the pulley, so you have to file the aluminum boss. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:35:22 Trimming the boss took no more than 3 minutes with a course file. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:36:08 Dave provides two stainless steel button head screws. Replace the stock 6mm bolts with these screws to make sure the pulley and/or belt doesn’t rub. One screw goes on the output shaft seal retainer as shown here. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:36:51 The other screw goes on the shifter mechanism cover as shown here. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/04/23 at 18:51:16 I had plenty of room on the swingarm, no need to file out the axle slots. I was done with the entire job in a couple of hours. I was running a Dunlop 140/90 rear tire. When combined with the 25-tooth pulley the final drive ratio was just under 14% taller. My cruising rpm dropped about 500. It made a big difference. Where I used to run at 4500 rpm on the freeway, now I cruise at 4000. At first, I didn’t care for it. It really dogged out my acceleration. The bike still had plenty of steam, but certainly didn’t yank like it did with the 23-tooth pulley and 140/80 rear tire. Over time, it grew on me. I have come to appreciate the reduced rpm. I initially installed it on my 94mm flat-top engine and now am running it on my 97mm pop-top engine with a four-speed trans. They're plenty fast. My fuel economy was not affected. I know this seems a bit haywire. The larger pulley and rear tire make the speedo and odo read a lot lower. The stock Savage speedo is optimistic. It indicates high. It’s my understanding that it’s about 10% high. That’s how the factory delivered it, and that’s what I suspect most Savage riders are using. Up to this point, all my mileage and economy data has been taken using the stock rear tire and gearing. So in the past, when I provided data related to speed or mileage, it was in “Savage Miles”. Moving forward, I intend to correct my mileage with the correction factor 1.138. That may sound wrong, but all my prior data is in Savage miles, so to do any sort of reasonable comparison I need to use the CF. If you’re lookin for a more relaxed ride, one where your engine isn’t runin it’s guts out and your hands aren’t numb from the high frequency vibes, then this pulley is the hot ticket. Trimming the spacer instead of the pulley results in about 4mm more spline engagement (a good thing), and it’s easier to machine. Hope some of you find this report informative. Best regards, Mike |
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Title: Re: 25T Pulley Installation Post by justin_o_guy2 on 02/04/23 at 19:29:25 I did not file the boss. Good thing I stuffed it into the side of that car before I fooled around and hurt something. |
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Title: Re: 25T Pulley Installation Post by Armen on 02/04/23 at 20:35:35 As always, interesting and informative! So, this begs the question-anyone have one of these spacers I can buy and chop down? Of course, I still have some of the modified Kawi pulleys…. |
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Title: Re: 25T Pulley Installation Post by Dave on 02/05/23 at 02:14:46 When I went to mount the longer spline pulley I made for myself....I also discovered the need to taper the splines. I don't know if this is the best method for machining the Kawasaki pulley for the general public. - but it does provide a longer spline for the pulley and I thought that was a good idea. I took pulley spacers off two engines - and they are really stuck on the shaft and getting them off was very difficult. There is a rubber O-ring inside the spacer that keeps oil from flowing out between the spacer/shaft - and when it is hard and has congealed oil and rust gluing the spacer on.....it required a lot of yanking and wiggling with big Channel Lock pliers to get it loose. (I don't have any spares). I like the reduced rpm that the pulley allows - my engine upgrades and lighter Cafe' bike have offset any acceleration drop caused by the pulley.....I am also running a lighter 18" aluminum rim and a 130/70-18 rear tire. |
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Title: Re: 25T Pulley Installation Post by Ruttly on 02/05/23 at 12:31:41 Dave , Do you know your final drive ratio ? Did you do both pulleys ? Did you or Ryca mod the swingarm to fit that 130/70-18 ? The 120/90-18 is tight , now you got me thinking ! I’ve been afraid to try 130/70 on my 2.5 rim , I think you’re running a wider rims ? What do you think? |
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Title: Re: 25T Pulley Installation Post by Dave on 02/05/23 at 13:02:18 Ruttly: The 130/70-18 does not fit a 2.50" rim properly....I have a 3.50" wide rim on my Cafe' bike. I did the RYCA thing with my first tire and put the 130/70 on a 2.50" rim - and the sidewalls are pulled in too far and the tread profile becomes overly rounded. I wore out the middle of the tread in 6,000 miles, and the tread on the sides was impossible to reach no matter how far you lean over. You did good by using a 120-90. Yes, I am using a 25 tooth front pulley and a 65 tooth rear pulley. Stock is 68/23 (2.9565) and mine is 65/25 (2.6). In 5th gear my engine is turning 3,500 rpm at 60mph, and 4,000 rpm at 70mph. The double pulley setup is not for everyone - currently only Badwolf and I have that gearing on our bikes. The double pulley setup moves the axle way back in the swingarm slots - I have plenty of room for the 130/70-18 tire without modifying the swingarm for clearance. |
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Title: Re: 25T Pulley Installation Post by Ruttly on 02/05/23 at 14:19:59 Then I think your 101 mph is conservative , with a 2.6 ratio and what ever mods it should march right past that. Mine wound up at 2.77 and the 120/90-18 is a tall tire too. It depends on the brands too , the same tire size but not the same height. Continental was taller than the same size Dunlop. What is overall height of the rear tire ? Dunlop 404 is 26 5/8 +/- I think me , you & badwolf need a long straight road. I don’t think DBM can attend but we extend the invitation. Someday the planets will align for us. |
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Title: Re: 25T Pulley Installation Post by Ruttly on 02/05/23 at 14:47:55 After that we hit the twisties ! ! ! |
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Title: Re: 25T Pulley Installation Post by Armen on 02/05/23 at 15:03:20 By the way-I have some 25T pulleys machined up and ready to ship! |
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Title: Re: 25T Pulley Installation Post by Dave on 02/05/23 at 16:50:47 123534342C39400 wrote:
My 101.1 was confirmed by my GPS speedometer....but the bike just wouldn't go any faster. The accuracy of the GPS is confirmed by the Garmin - but they both are likely using the same satellites! I believe my 36mm carb , stock header and double baffled muffler are likely a bit of a hindrance for my terminal velocity. My fastest mph is obtained in 4th gear - in 5th the engine stops pulling at around the 85-90 mph range. The smaller carb and restrictive muffler do however run really smoothly, and the neighbors appreciate that the bike is pretty quiet (they have all their fingers up when they wave at me). Most of my riding is done at 50-60mph on the back roads and I seldom need more than half throttle to stay at the speeds the roads can allow. I will be removing the 95mm pop top Wiseco and installing a 97mm flat top before long, installing the MAC header and a muffler that I got from DragBikeMike......and installing a steering damper as the darn bike gets wiggly as you approach triple digits! |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/06/23 at 16:48:30 Hey Armen, I have an extra spacer. I will send it to you. Do me a favor. There are two 6mm tapped holes in the 25T pulley. They are adjacent to the internal splines. Can you check to see if they can be used to lock the pulley nut (ala Harley Davidson). I never checked and I'm too lazy to remove the nut and lock tab washer. If a socket head cap screw or set screw can be installed against a flat on the nut, we can ditch the lock tab washer. Dave, I'm relieved to hear that I'm not the only one to struggle with that spacer. Those suckers are quite a challenge. I hate grabbin on to those things with pliers. It chews them up good. A method that works well for me is to use a hose clamp. You can then grab the clamp without chewing up the spacer. It also allows the use of a screwdriver to pry the spacer loose. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/06/23 at 16:51:05 A small hose clamp works great on the dowels too. Just make sure there is a bit of clearance between the worm-screw and the deck so you don't mar the critical sealing surface. |
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Title: Re: 25T Pulley Installation Post by DragBikeMike on 02/06/23 at 16:58:02 Thanks for the invite Ruttly. You are correct, that excursion would be outa my tax bracket. Alas, I am also gettin too old for those sorts of shenanigans. Over here, there's no place to stretch its legs. Ya run outa road long before you can reach terminal velocity. :'( |
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Title: Re: 25T Pulley Installation Post by Ruttly on 02/06/23 at 17:42:05 Yeah I’m a bad influence to all I meet ! But that’s the whole point of the gps speedo & rewire. Get data , well I think it only does 0-60 , 1/4 mile , WFO/ top speed. After all that you can bet , I’m gettin some numbers to post. I just want to know if it’s worth a Dyno session. It would really have to impress me before I did that. I don’t think it’s all that fast. We will see. |
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