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Post by sarniarebel on Feb 27, 2011 23:45:16 GMT -5
i finally did it. just purchased my 90cc 2t engine from scrappy's. this vino sure is gunna fly when im done with er!
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Post by Rebel on Feb 28, 2011 0:35:51 GMT -5
I'm guessing it will need the jet upsized too, are you porting the head, getting a tuned exhaust? Tuning the variator?
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Post by sarniarebel on Feb 28, 2011 3:26:10 GMT -5
I don't think I'll need to port the head. It's the complete 90cc, not a 50 with a bbk. As for exhaust goes, I have a polini for race 3 pipe and an aftermarket freeflow pipe that I think will work nice on it. I'll definitely be upjetting. I have an old 19mm carb from an old project that I think will work nicely so I'll try that with a little larger jet. As for the variater, Im think some 6g or 7g sliders. I want more top speed then acceleration.
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Post by Rocketdog on Feb 28, 2011 7:06:13 GMT -5
Sarnia, on some two stroke kits, I understand that it might be necessary to chamfer the ports of the new cylinder. They are left sharp by the boring and it is detrimental to piston longevity if you don't. I haven't done one yet, but it makes since. Anyhow ask around to be sure.
RD
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Post by Rebel on Feb 28, 2011 12:38:09 GMT -5
Well, he got a complete new motor, not a BBK, hopefully the factory built it right. But checking might be a good thing.
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Post by sarniarebel on Feb 28, 2011 16:30:53 GMT -5
Well according to scrappy's the engine is plug and play. So I do think I want to go and rip it apart. Just seems like quite a bit unnessecary work.
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Post by Rebel on Feb 28, 2011 17:01:39 GMT -5
understood, and I don't blame either for that. If it takes off and runs the way you want, no need to do anything to it.
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jmkjr72
contributing staff
Commander 132nd Northern Cav. Division
Posts: 2,779
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Post by jmkjr72 on Feb 28, 2011 17:53:50 GMT -5
it doesnt take much to check to see if they are chamferd and what the squish is set at i have seen a few brand new engines with busted rings
guess its just me im anal about fresh builds even if some one else built it for me
that 90 is not a screamer so you may need even more then 7 gram rollers to start with
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Post by 90GTVert on Feb 28, 2011 22:55:09 GMT -5
You'll probably be fine if you don't pull it apart and chamfer, but it's not a bad idea to do it. I look at it this way, it's built the same as your 50cc engine. Do you think the dealer took it apart and chamfered the ports before they started it? If you feel like doing it, it's a good thing and it could increase ring life. If not, it'll probably be fine too.
I've got a 90 in my Venus (Vino clone) and I love it. It's been modded a bit beyond just a stock 90, but quite fun.
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Post by sarniarebel on Mar 1, 2011 0:18:06 GMT -5
heck, i guess i should to be safe. and 90gtvert, what would you recommend for upgrades to the 90?
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Post by 90GTVert on Mar 1, 2011 8:24:06 GMT -5
A pipe would be a good start. I've got a Phongeer pipe for a 100cc BWS that looks almost like a stocker, but it performs a lot better. It makes good power up to a bit over 9,000RPM, but delivers a lot of torque compared to a racier pipe. It's fairly quiet, so combining that with the look, it's a nice sleeper pipe that won't draw a lot of attention. I got that from VT Cycles for $145 shipped IIRC. It's not on their site, so you'd have to call or email them.
I've also got a Leo Vince ZX for a 100cc Aerox. It's a little more sporty pipe, that makes good power to the upper 9,000RPM range. It doesn't produce as much low end power, but it is capable of slightly more power at the higher revs. It is a standard looking tuned pipe, and louder than the Phongeer. One bad point of this pipe is that it's restricted stock, so you have to work on it to get the most of it. It was about $280 including overseas shipping from SIP-Scootershop. You could probably get a better deal from a Leo Vince dealer in the US. At the time, I contacted Leo Vince USA and they told me it would be a long wait. They didn't stock them and had never imported one for a 100cc in the US at that time. These big motors have become way more popular of late, so it might be easier now.
There are others out there, but those are the two I have personal experience with. Pipes for the bigger motors are way more scarce than 50-70cc pipes. Even some of the overseas sellers seem to be taking out a lot of 100cc inventory for some reason.
A larger carburetor isn't a bad idea either. If you go with a more racey pipe, I'd try to upgrade the carb along with it. You can get a 21mm DellOrto and fit it into the stock intake, so you wouldn't need the extra expense of an aftermarket intake. You may wish to port the stock intake just slightly to match the 21mm carb. They're typically rubber intakes, so it's pretty easy.
I think an aftermarket vari, like the Hoca model from PartsForScooters is a good idea too. They are about $50, and they are more capable of handling 90cc power without more tuning headaches from my experience. If you go with that, it moves up to 16x13 rollers or sliders, vs the 15x12 that stock minarelli engines use. Just wanted to note that so you don't stock up on 15x12 stuff to tune if you buy it.
You could tune the stock cylinder a bit too, and perhaps replace the stock head with a squish band style head. If you want to tune the stock cylinder though, I suggest knowing what pipe you plan to use so you know what RPM range you are shooting for. If the pipe and the cylinder aren't on the same wavelength, you'll never see it's real potential.
My Venus has the Phongeer pipe, tuned 54mm BBK, Hoca vari, 21mm Dellorto, ported stock intake, Malossi reed cage/CF reeds, stock 49cc gears swapped in for the extra torque, and of course CVT tuning with springs and sliders. I'm 285lbs and it will get me to 50MPH in about 1/8 mile. Max speed so far is 61MPH @ 9100RPM. Compare that RPM to where most 70ccs rev to accomplish 60MPH and you'll start to see the beauty of the 90s. And remember, that's with deep gearing for takeoff, not top end. It can power wheelie, and with some ways I set up the vari it WILL wheelie (meaning it's hard not to pick the front up just a little leaving red lights). Riding as I normally do it gets about 45-50MPG. Using heavier sliders to keep the revs down more, if I cruise it easy at say 40MPH max and don't use much throttle accelerating (you don't need to) I have seen just over 70MPG. Cops pay no mind with the stock airbox and stockish Phongeer pipe, so if you aren't doing anything crazy, you'll be under the radar. ;D
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Post by Rocketdog on Mar 1, 2011 9:08:41 GMT -5
Well, he got a complete new motor, not a BBK, hopefully the factory built it right. But checking might be a good thing. Ahhh. I miss read it. I thought it was a kit. RD
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Post by sarniarebel on Mar 1, 2011 11:37:59 GMT -5
i already have a pipe that is going to work great for this build but i think thats about it right now. i was planning on using my 19MM dellorto carburettor that i ripped off my 70cc bbk engine. i THINK it might be jetted perfectly for the 90CC already if i use the air box because the thing ran pretty rich with my free flow air filter on it. and as far as using the stock air box, would i just drill some holes in it or just remove the snorkle
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Post by 90GTVert on Mar 1, 2011 18:07:18 GMT -5
I just removed the snorkel. I don't think you really need to do that, but it made me feel better. lol
Just be careful with the 70cc pipe. I had one 99cc that really didn't like my 70cc pipe. It kept soft seizing until I replaced it with a pipe built for a 100. I've had other 90s seem OK with the same pipe, but I wouldn't try it for long so I'm not sure if it would have built up more heat over time or not. I was pushing it on compression too, so I think the compression as well as smaller stinger diameter might have teamed up to give me headaches. Hope it's a non-issue for you, and it probably will be. Just one more thing to think about just in case you ever have a problem.
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Post by sarniarebel on Mar 1, 2011 18:43:19 GMT -5
ill be sure to watch it carefully but i think it should be fine. the pipe is listed as a 90 pipe on the website. it is definitely larger than my 50 pipe.
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