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Post by jerryscript on Apr 15, 2015 10:49:23 GMT -6
5- valve lash, set to .004. I've fixed more friend's hard starting problems with a valve adjustment than anything else.
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Post by jerryscript on Apr 15, 2015 0:18:38 GMT -6
Those measurements are at the center of the bolts, edge of bolts would be 54mm or so, ironic and could confuse people, definitely has me confused. I may take a ride over to Scrappy's and measure a couple of their heads to get to the bottom of this once and for all. I can tell you that the BN139QMB has standard stud spacing, but a different stock head (still takes standard head replacements fine, but rocker arms have to be switched). IF you have 57mm center to center, it's a b-case.... I currently own a couple of Taida engines that are b-case and I have personally measured them..... I also have a scrappy 161QMK, b-case also.... I'll tell ya where the confusion comes from: It's the BN that ZNEN attaches to their engine stamps. I have 2 ZNEN engines that are stamped with BN157QMJ, a short case and a long case.... I thought I had b-cases... After many hours of research I learned that "BN" was just an identifier for a ZNEN engines. However, I also learned that the engines with a -3 is a new type of GY6 engine that was designed to accommodate the larger 16" wheels. The information I could not find is wether it's a "b" or an "a" case... However, If you measured 57mm center to center, the issue is put to rest because it is in fact a b case. The BN stands for Benneng engines, a brand Znen created in 1999, here is Znen's history up to 2010, though it's mostly self praise: www.znen.com/history.asp |
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Post by jerryscript on Apr 13, 2015 19:39:29 GMT -6
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Post by jerryscript on Apr 13, 2015 19:33:18 GMT -6
Headlights being blown is often caused by a bad R/R, and with all the electric issues you have, it's worth checking. Check the power coming out of your R/R when revving the engine up high. If the voltage goes over 14-15v, it's definitely bad.
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Post by jerryscript on Apr 13, 2015 18:47:10 GMT -6
Those measurements are at the center of the bolts, edge of bolts would be 54mm or so, ironic and could confuse people, definitely has me confused. I may take a ride over to Scrappy's and measure a couple of their heads to get to the bottom of this once and for all. I can tell you that the BN139QMB has standard stud spacing, but a different stock head (still takes standard head replacements fine, but rocker arms have to be switched).
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Post by jerryscript on Apr 13, 2015 9:21:18 GMT -6
2.25" across, 3" diagonal stud spacing.
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Post by jerryscript on Apr 13, 2015 0:02:44 GMT -6
I just crossed the 1250 mile mark after my ride today through my favorite parts of town to ride in. I wanted to share my thoughts, and a wholehearted recommendation for one of the 16" wheeled models.
I started looking for a new scooter towards the end of last year. I started a new job that has me working at various locations around the valley, and was looking to move up to a 150cc. I had always liked the look of the 16" models, but couldn't find many posts relating to performance, though I found many warning about difficulty finding parts.
I started searching for parts before ordering the scooter, and was happy to find that more parts dealers are carrying parts for the BN157QMJ-3. I've found a half dozen dealers with parts, and between them I'm confident I can get anything unique to this engine, and even a complete replacement engine if needed. Even the unique CVT parts are more easily found these days. After measuring the engine stud spacing, I'm happy to find most BBKs will work as well.
Performance of my stock scooter has been very good. Take off at half throttle leaves cars in my mirrors, and cruising 45-55 at 3/4 throttle leaves enough extra throttle when needed, and keeps me at the head of the pack when riding around the valley. I've had it to just over 70mph on the freeway for short periods, and the 16" wheels give a smooth stable ride at all speeds. The taller wheels and different CVT and final drive gears give the 16" wheeled 150cc models about 15mph more stock than standard 157QMJ models. I plan on upgrading to the 61mm NCY BBK this summer, with appropriate sliders to tune the CVT I hope to top 80mph with a bit of throttle to spare. My variator shows more than 3/8" unused at the edge, so I'm pretty confidentconfident I can get there.
The 16" wheels and size of the scooter give it more of a small motorcycle look and feel. It is no where near as nimble as my 50cc short case with 10" wheels, it turns much slower, but leans better in turns. Riding over a manhole cover with 16" wheels is nothing compared to the spine jarring jolts I experience on my 10" wheeled scooter, and the adjustable dual rear shocks make it tunable for me alone or with a passenger with a quick turn of the adjusters.
So if you are on the fence between a 150cc and something larger, but are not looking to tour the country on it, I would highly recommend getting one of the 16" wheeled 150cc models. At around $1500-2000 depending on where you purchase it, you will get the most bang for your buck, and have a ride that gets constant compliments! BTW- the dark blue paint job on my model is beautiful!
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Post by jerryscript on Apr 13, 2015 0:01:14 GMT -6
With the front wheel raised, can you pull it at all? If so, you need to tighten the two giant nuts on your steering stem. The top one is a lock nut, loosen it, the tighten the lower one till the handle bars only bounce once when asked to fall to one side or the other when the front wheel is of the ground. Then tighten the lock nut back down.
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Post by jerryscript on Apr 12, 2015 2:32:05 GMT -6
I wonder if this is the repercussion if Tesla trying to sell without dealers? I realize the California issue is emissions, but I wonder if the other states are dealer only states?
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Post by jerryscript on Apr 10, 2015 15:48:20 GMT -6
I've ridden and left mine outside at work all day in the rain, no issues yet. These scooters are definitely not water proof, but most connections seem placed in pretty safe locations. I'm hoping you just had a defect in the switch, fingers crossed.
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Post by jerryscript on Apr 6, 2015 18:05:38 GMT -6
Thanks JR! And R.I.P., Ride In Peace Rich!
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I am done!
by: jerryscript - Mar 29, 2015 16:40:33 GMT -6
Post by jerryscript on Mar 29, 2015 16:40:33 GMT -6
The 75% is good advice. Think about it, most cars are designed to break 100mph, but very few people ever take their car to that speed. The long life of a well maintained car engine is definitely related to the fact that cars are almost never driven at WOT.
As for the issue of this thread, I went for a ride with some friends on their Hogs yesterday, yes I put up with all the grief for riding my puny scooter! Funny thing is, I kept up fine with them, adn when one of them broke down, I noticed some of the parts they removed while fixing it had some Chinese looking markings on them, and they were not the broken parts. Point being, I don't care what you ride/drive, I would bet a paycheck it has Chinese made parts in it! The only thing I can see the Chinese do wrong as a rule of thumb is use substandard wiring.
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Post by jerryscript on Mar 28, 2015 0:59:37 GMT -6
The chain should only "droop" until the tensioner is in place, then it should be just snug but not tight.
I would not recommend using chains not designated for this purpose, there may or may not be specifications we are unaware of.
There are three main engine sizes for the 139qmb, but AFAIK, there are only two cam chain lengths (could be wrong).
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Post by jerryscript on Mar 25, 2015 1:30:35 GMT -6
I used a stock head on my 83cc BBK for a year and a half, then one of the rocker arms pushed through the valve seat when I was going downhill over 45mph. Ended up dropping the intake valve into the cylinder, which left a nice hashmark pattern all over the top of my piston. Had to do a head replacement on the side of the road, and of course the new head had different rocker arms, so it took two trips to Scrappy's! The Vegas god's were on my side, since I was only 6 blocks away from Scrappy's when it happened.
I put Scrappy's performance head on, not the big valve head. I'm very happy with it. I cannot offer advice on the big valve head, but just wanted to share my experience with running a stock head on an 83cc BBK.
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Post by jerryscript on Mar 22, 2015 2:06:17 GMT -6
Try watching some police training videos, and then see how comfy carrying makes you. If you don't have your weapon out of the holster, you are in danger from anyone within 30 feet of you. This is why police are trained to pull their weapon while you are at a distance, and why they will shoot if you break a certain perimeter while armed.
Once again, I don't want to sound like I'm against carrying. I just want people to understand possessing a weapon does not in and of itself mean you are protected. Actually firing your weapon at a person will bring you misery you probably don't want to experience, both legally and emotionally.
I have personally witnessed a person point their handgun at another individual, and the target stepped forward, grabbed the gun in the wanna-be-shooter's hand, and smashed it into his face breaking his nose and spewing blood everywhere. Things don't always go the way you think they should, and a weapon can be taken away from you and used against you.
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