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Post by Silar on Apr 30, 2015 16:36:22 GMT -5
I bought a whole BBK kit from 02starrider on ebay for $55 it came with piston, rings, cylinder, head (complete w/rocker arms), oil pump gear, roller weights, main jet, gaskets, etc. etc.... bought the exact same kit... I opted not to go with the 69mm valve lengths and get this... 02starider BBK 50mm kitYou may want to get one of the 47mm kits instead of the 50mm kit if you plan on riding the scooter at WOT all the time.
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Post by Silar on Apr 30, 2015 7:44:44 GMT -5
Thanks. I do tend to try and do multiple things at once which usually bites me in the end.. Like this one. I had it running great with the stock air box with no internal or external snorkel, but I knew I was going to get the cone filter so I up jetted to #95. And set the needle to rich to try and compensate, even before testing, but I think it was probably more of a minimal change on air flow and would have been fine where the needle and jet were with the semi open air box. Probably not much of a change.
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Post by Silar on Apr 29, 2015 20:56:47 GMT -5
Had a chance to ride with a friend yesterday. His scoot - 170lbs 49cc bone stock. Rider weight 185lbs Total weight 355lbs My scoot - 190lbs 83cc BBK and 6.5 rollers, 90 MJ (nothing else). Rider weight 205 (as of last week) Total weight 395lbs Acceleration - No contest. My scooter walks away Top Speed -
He's fading in the rear view mirrors. His top speed was about 35. Mine about 41. These were not Chinometer guesstimations but GPS verified. Now granted you might hear some saying they hit 44 or something like that on their stock 49cc scooter. I say that is pretty darn hard on a stock 49cc scooter on level ground with no tail wind. Downhill with a tailwind....maybe so. We then switched scooters. Again, my scooter dusted his. The 49cc scooter struggles to get to speed and maintain it. The BBK scooter climbs quickly to top speed and holds it fairly easily. So even though my scoot was heavier by an extra 20 - 30 lbs it clearly outperformed the 49cc scooter. Conclusion..... If you've been wondering if just a BBK and nothing else would make any difference the answer is yes. Acceleration is significantly improved but also the BBK's help the scooters keep speed in headwinds and on hill climbs. I was especially impressed with the improvement I got facing headwinds and going up inclines. Gas mileage is around 80mpg. I can hit 100mpg with conservative driving. Don't expect miracles. With just a BBK you're not ready for drag racing. Cars will still be passing you and you'll still find that 40mph or greater speed zones have you lagging behind cars....but...compared to 49cc, it's significantly more comfortable. The cars are going by much slower than they were at 49cc so you're not feeling like you're impeding traffic as bad. How long will it last? All depends. I try not to push mine too hard. I find with the BBK 35mph is a very easy and comfortable cruise speed so most of the time I try to just stay at 35. Now if you want to hang with cars in the 40 - 45 mph zones, add an A9 cam, big valve head and 20mm carburetor. I just ordered my Big Valve Head and 20mm carb so I'll update this thread with the results soon. There are members here with FAR more modified scooters that can top 60mph....but this info here is mainly geared toward the average or noobie scooter rider just curious what he can get with fairly easy and inexpensive bolt on mods. Just curious, but what do you have your carb needle clip set at? What size is your carb? I'm running a #95 main jet with a 18mm carb but have the cone performance filter, performance CDI, A9 Cam and 50mm BBK that came with a new head also.. Awesome info though! I'm about 195lbs so not to far off from you. Been tweaking mine for the past few days now...
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Post by Silar on Apr 29, 2015 20:20:57 GMT -5
This exactly: "if you are idling ok and then give it gas for a second and when letting off gas the idle lopes (drops down) before coming back up, usually i take that as a sign of being rich up above idle."
I've got the #95 in and have the needle clip set to richest and the needle may be my problem. I'll start taking it back to middle and lean to see how that does.
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Post by Silar on Apr 29, 2015 20:14:38 GMT -5
i think you might be lean on the main jet. i'm running an 85 main in a 47mm bore with mostly stock airbox. Hey Upgreyedd! Really? I was kinda wondering that. I'm starting to think about putting the stock airbox back on just to avoid any issues. Could there be a chance that I need to go up a step in my pilot jet also?
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Post by Silar on Apr 29, 2015 20:03:24 GMT -5
Maybe I jumped the gun... This is with a #95 Main Jet, needle clip at bottom (most rich) position. Idle is currently at about 2200rpm. Anyone want to diagnose my plug? I'm guessing it looks pretty okay. Any other reason why the scooter would die as it drops down when I just rev it?
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Post by Silar on Apr 29, 2015 19:27:49 GMT -5
Finally got my scooter running, and I've been playing around with different settings with the carb just to see what it would do. I want to make sure I'm not running into a too lean situation and cause my engine to overheat.
Here's my current setup:
50mm BBK Cone air filter 18mm Kei-Hin carb #95 main jet Needle clip at middle position Idle Air Screw pretty well optimized for the best running idle Blue performance CDI
All this is new as of the past week or 2.
With this setup, the engine takes a couple cranks to get up and running. Seems to idle fine, but if I blip the throttle to about half and let it go, it goes up in speed, then drops and dies. Almost like I've got a too rich condition.
If I put in the #90 main jet, set the needle clip to the top position (more lean), and start the scooter, it seems to like that better. Starting is much more responsive and I can blip the throttle to rev it like before to about half and even the engine is much more responsive and drops back down normally without dying.
I'm trying to avoid causing burnt valves, or ring issues, but this seems weird. Carb float and valve seems to be working fine and I have the float properly adjusted. I'm getting ready to pull the plug out and check to see how it looks, but when I checked it before it looked a bit rich...
I've seen where guys are putting 20mm carbs or more in their BBK's so me having an 18mm makes me also wonder if anything larger is just too much.
Any thoughts?
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Post by Silar on Apr 29, 2015 19:13:23 GMT -5
Great post Silar. Sometimes even the most experienced can overlook things or forget them. I know.. It's something that I never thought would be the problem and didn't even see it since the factory lines are black.
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Post by Silar on Apr 28, 2015 20:33:52 GMT -5
I changed the fuel petcock valve and still won't start....I'm thinking now that it could be something in the engine like a broken piston ring. I took the oil dipstick out and oil started pouring out of the dipstick hole....there is built up pressure, what all could cause this? I oulled the hose off of the valve cover that goes to the air intake. The scooter started right up and was running but then oil started to shoot out of the valve cover hole. Do you guys know what this means? I think I bought a POS and the engine might need to be rebuilt. Not sure exactly, but you could get a decent 47mm big bore kit for around $40-$50 and put that in, or opt to get rings, seals, etc but you still are not sure about the valves and everything else. I'd do the kit since that'll replace pretty much your entire top end and it's cheap.
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Post by Silar on Apr 28, 2015 16:20:16 GMT -5
Good point..
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Post by Silar on Apr 28, 2015 16:19:00 GMT -5
Can you post a picture?
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Post by Silar on Apr 28, 2015 12:34:50 GMT -5
The pressure from compression in the cylinder will blow out that soft gasket..
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Post by Silar on Apr 27, 2015 19:11:58 GMT -5
I pulled the vacum line off the intake, it was leaking gas out.....the fuel petcock must be the problem as you guys mentioned. I'm going to the scooter store tomorrow to get a new one. Should be finally riding, I appreciate all your guys help. Hopefully this is all....this scooter was farm fresh when I got it. You may want to try to wick out any gas that may be in the cylinder. You mentioned it was hard to crank it over with the kickstart almost like there was crazy compression you were fighting against. I'd make sure all the gas is out of the cylinder first before trying to start it again once you get the problem fixed. You could be hydro-locking your engine. Go to autozone or advance auto parts or whatever auto store you have and replace the vacuum petcock with a manual petcock. They are usually there under the small engine section like for lawn mowers. About $5. Get rid of that thing as fast as you can chuck it out the back yard! Apparently they are very prone to failure and you are having the exact same problem I had except mine would start but it would only go about 10 mph. I threw $200 in parts at my scooter including a 50mm big bore kit, new carburetor, A9 cam, Gates Kevlar belt, sliders and rollers, etc.. and to find out all the time it was just a simple $5 petcock replacement. Of course now I've got my scooter going about 45 mph or more (haven't taken it out on a flat stretch of road yet)!!! More or less gave me a reason to make a mini muscle scooter and my wife thinks it's all to fix the problem! Also, make sure you report back to let us know!
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Post by Silar on Apr 27, 2015 8:50:13 GMT -5
That's a pretty good idea Fox! I may just have to do that!
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Post by Silar on Apr 27, 2015 6:03:32 GMT -5
We can definitely say this problem is solved!
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