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Discussion Starter · #1 ·
Just a quick rundown of what I got. Cheetah PV 535cc. Crankworks 10mil billet crank, 25cc domes, 198psi, +7 timing, 39mm PWK's, VF3's, CPI big bore inframes, Direct Drive lockout with 2 weights on each finger. I'm at sea level, with 52 pilots, CGK middle clip, 178 mains, and 1 turn out. Running Sonoco 110octane, with Maxima Castor927 @ 40:1.

The only place close that I could find, that would dyno my Banshee, had an automotive DynoJet. I know a few people that don't like that brand of Dyno's. Anyways, the first pull was with 180 mains. It pulled only 54hp, and 48ft/lbs. WTF? Then switched to 178 mains, and pulled 64hp, and 68ft/lbs. I've never seen a 2-stroke gas engine have more torque than horsepower before. And I know this motor should be putting out numbers above 115hp. I was expecting the torque to be somewhere around 60-65. Not to mention, the graph showed the hp fall to 0, after 9,000. But when you ride it, it still pulls strong until about 10,500.

Is their dyno screwed up? The guy that did the pulls thinks that I need more timing. I'm not too sure of that. I think I'm at the limit of what the 110octane can handle. At first, I thought the tires were spinning. We checked , and they weren't. Then I thought clutch, but the motor doesn't act like it's slipping. What's going on here? Thanks.
 

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Discussion Starter · #2 ·
Oh, forgot to mention. My old 4mil stock jug, trail port was putting down 65hp. My 10mil Cheetah is a wheelie machine, with the +6" swingarm. There's no way my old 4mil would even think about touching this bike now.
 

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Those numbers are not right unless it was ported at the Walmart Service Center. I use an automotive dyno jet dyno and it is pretty hard to get the tires to hook up. The distance between the rollers is so big that only about 20% of each tire is making contact with the rollers. To make matters worse, the one roller is smooth on the inside due to the dyno brake so that tire doesn't hook up well. We usually have the quad sit mostly on the knurled roller without the brake.

For you to be making more tq than hp your rpms would have to be below 5252 which is almost impossible for a banshee.

Your timing is good. I would not dare go much higher on gas. My 4 mil will usually rattle the plugs; ie deto. if I go to +8 or more.

Do you have a run to post on here? That would help. It sounds like the guy didn't know what he was doing though.

Do you have a pvl ignition or stock? The pvl will mess up the computer.

Who ported it? What are the port timings at?

Mailman
 

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That dyno is probably not gonna read right on your bike. I used a friends at his shop and got messed up results as well. Just use it to tune A/F ratio and don't worry about it. The dyno we used had a 1500 lb roller and read wrong all the time. It just has one 7' wide roller.
 

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Discussion Starter · #6 ·
The dyno was a single roller, and both of my tires were on the knurled parts of the drum. My bike is wide, compared to you drag guys. He told me it was a 2000lb roller. I have a stock CDI and ignition. I didn't even bother getting a printout from him, because it was too embarrassing. haha. But the curves were all over the place, up and down, up and down. M&M did my porting, and whoever his plater is did the Nikisil. I honestly don't remember the port timing right off hand. I can't remember where I put the paperwork to it. Everything's brand new. Only about 15 hours on the motor.
 

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Discussion Starter · #9 ·
Yea, it seems pretty good to me. I jetted it as close as I could by plug chops. That was 55/178. I knew I was a tad fat on the pilots. I borrowed my brother's air/fuel monitor machine and O2 sensor yesterday, and I ended up going down to 52's and up to 180's. That seemed perfect, and pulled like a freight train. While I was on the dyno, I dropped the mains back to 178. Doing that showed 10 more hp on his machine. I've never ran anything on a dyno, so it looked kinda weird to me, getting that much hp from 1 size smaller jet. It did sound kinda "zingy" up top with the 178's. I think I might go back to the 180's. I'm more comfortable with those.
 

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Discussion Starter · #10 ·
QUOTE (Radar @ Aug 5 2009, 08:37 PM) index.php?act=findpost&pid=52344With a plus 6 it shouldn't be rideable hardly.
haha, I just seen this. I actually trail ride and hillclimb this bike. They're very aggressive and really fast trails, with lots of steep hills. My bike is actually very rideable on the trails, believe it or not. The +6 swingarm is perfect, for the dirt and the tires I use. It's different having power valves. You can control how much of the engines power you use with the throttle, and it's very smooth. Now, if I get on the street, and give it a little gas, I'm looking at god.

Thanks for the help on this though. I left that dude's dyno pretty mad.
 

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Oh don't be mad at the dyno or the bike you just aren't gonna get a good reading on it. When my buddy Marks dyno was recalibrated up from 800 hp to 1200 then a lot of the smaller cars weren't even readind right. He runs 1200 hp drag cars and 900hp diesel trucks and the 800 hp settings wouldn't work on the big stuff, now he can't do the small stuff.
 

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Discussion Starter · #12 ·
Ok, that makes sense. So, if I really want to get a good reading, I need to put it on an ATV dyno, that's made for small motors. There's a bunch of dyno's in the area, but this guy was the only one that could get me in yesterday. I originally brought it to a place that has an ATV dyno. I called him 2 hours before I came, and told him I was bringing my bike. When I got there, he told me that he had an engine torn apart on it, and couldn't get my bike on it until Saturday. So, I was in the mood, and got on the phone to find someone that would get me in now, since I already had it on the trailer, with more tires strapped on the trailer, and tools and jets all loaded up. I should've just waited until Saturday, got a better reading, and spend $15 less doing it.
 

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You'll also not get a very high reading on that cheetah on a dynojet atv dyno unless its geared high or the dyno has a brake to put a load on the bike. Its gonna show low unless you gear it pretty high and can put a good load on it. The best ones have an eddy current system. Last time we had a dyno day at Kevin Gigots shop a cheetah made 81hp with no load and 101 with a load.
 

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15-39???????? HeckI run 16-38 with my 7MM stock cylinders, gear that thing up man.
 

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Discussion Starter · #16 ·
10-4. Only thing is, I don't drag race on a daily basis like you guys. I ride aggressive trails, and steep dirt hills. I thought about going to a 16 front, for the trails/hills. I just don't want to gear it so high, that I lose power on steep hills.
 

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There is def something wrong with the dyno esp if you said it dropped off to 0 at one point. We have done alot of the 535 and they all run awesome i assure you that it is not a 68 hp motor unless you have a big problem and you would know it if you did. Feel free to give me a call if you need any help with it.

Andy
M&M
 

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Discussion Starter · #18 ·
lol. Thanks Andy. I trust your work. And I know this thing's putting out more than 64hp. I'm just aggravated that I didn't see what I paid for, on that dyno screen. It's tuned pretty close to perfect. I was just curious what numbers it was making. I'm out a little bit of money for the pulls, and still don't know. I just feel like I got ripped at the dyno. I kept telling the dude it wasn't right, and his response was "I live on this machine", and "I don't build the motors, I just tune them", and "The seat dyno lies". What a clown.
 

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i have a stock cylinder that pulls close to 75 hp... if urs are that low somethin is wrong lol
 
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