nobake
Scoot Member
lifes a gardin dig it
Posts: 38
|
Post by nobake on Jun 1, 2011 22:51:58 GMT -5
cyberbeer65 what kind of gas millage do u get in your scoot if you dont mind me askin
|
|
|
|
Post by boarder4life501 on Jun 21, 2011 16:31:41 GMT -5
I only read through the first couple threads but i put a 50mm 80cc kit on my qmb139 and i put 15k on it before the piston its self came apart. I checked my baring and they where fine so i just put the stock one back in and then sold the scooter but my stock baring worked just fine but i would recommend putting new baring in just to be safe if your going to bore that big.
|
|
|
|
Post by speedy1125 on Sept 15, 2011 17:13:33 GMT -5
5 months and 1250 miles on mine so far. still runs strong.
|
|
powerwheely24
Scoot Junior
snapping my gates powerlink p.o.s. belt!
Posts: 6
|
Post by powerwheely24 on Sept 25, 2011 9:05:17 GMT -5
I have a gy6 with
50mm Airsal ceramic high compression (11:1) BBK (had the compresion tested to make shure)
naraku reinforced crank
tomax cam
NCY 80cc raceing head
18mm CVK carb with polished venturi
aluminum intake
fully port polished and port matched
free flowing header and exhaust
NCY oil cooler
full cvt and upgear 15%
10in rim
bunch of other shit
55mph ALL DAY!
I had a fuck up tho.. I was ridin out for about 5 miles and when we got there I had a dumb ass airfilter that always gave me problems. It moved and my tire rubbed a hole in it and was sucking up all kinds of shit. It ended up fucking my crank bearings it was my fault tho I should have put a propper air filter that wasent going to rub my tire.
|
|
|
|
Post by speedy1125 on Oct 14, 2011 22:03:47 GMT -5
I have about 2500 miles on this build and its starting to come into its own. the low and midrange power just keeps getting better, even more-so now that charge-air is cold and dense. I have been pretty easy on it the past 2000 miles but now i can tell its broke in and ready for some sustained WOT rides. Today i replaced my 5.5g flatted rollers with some new 5g's from ScooterAssassins + 1500 clutch springs from PFS. She hits hard off the line and at my body weight will pull the front tire up if i dont lean forward, as i said the low-mid torque is awesome. On WOT runs with no wind and flat ground like today she runs an indicated 54mph. She cruises 45-50 quite easy. The cagers around me in these posted 45mph zones seem to be doing about what my speedo shows, so i think its pretty accurate. In other words, they run at least 5 over everywhere you go here and i am easily keeping up in most areas.
I am happy with this build so far.
The best mod i feel was the magnetic drain bolt kit from Envriomoto. The chinese dont do much rinsing out of these cases and gearboxes before they are built and shipped. my gearbox was full of glitter so bad when i first got it that i bought a good used gearbox off ebay thinking mine was surely toast, it barely had any lube in it too and silly me didnt check it during the PDI.
The MagBolts have collected LOTS of metal, so much that i was worried that the engine was never gonna see another 100 miles. upon my last oil change though, the oil was clean and metal free. Its my belief that many-a-downfall of a 50mm motor is from the crank bearings grinding up this metal left over from the factory so i STRONGLY recommend the Prima Magnetic Drainbolt Kit from Enviromoto.com
Next on my list: 54x44 Longcase QMB 95cc Stroker! :devil:
Happy scootin friends! :riding:
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 8, 2012 10:57:33 GMT -5
I think these 50mm bores are getting a bad rap from folks who are overloading the bikes in the first place. I am 180lbs and have over 4000 miles on my first 50mm motor which was already factory 47mm and it runs beautiful.
Your thoughts?
|
|
|
|
Post by larry001964 on Mar 8, 2012 11:13:55 GMT -5
I weigh 220 pounds, and according to shipping my bike weighs 220 pounds. I had never heard of overloading before. You mentioned this before 1fastqmb that the qmb has a design load of 220 pounds.. What exactly is being overloaded ? is it the stresses on the crank, bearings, can the load the bike is capable of be increased thru the use of heavy duty, quality parts ?
You really have my curiosity going now what's being overloaded and how do we fix this.. It's the first time really and honestly I have ever heard of this concept so I would really like to know more..
|
|
|
|
Post by 90GTVert on Mar 8, 2012 12:29:25 GMT -5
Increased load causes increased cylinder pressures, which do cause more heat and stress. An easy way to imagine it to some degree might be to think of revving the engine on the stand vs with you on it. One way it almost free revs, the other it's fighting the load and is far from free revving in most cases.
Weight couldn't explain it all IMO, because there are lighter people that have had the same problems. If you think engine loading is the problem, you should also be against heavier rollers, lighter contra springs, upgears, larger diameter wheel/tire combos, and things of that nature. All of those would decrease the mechanical advantage of the CVT/final drive and have much the same effects as a heavier rider. I feel like a properly tuned CVT would keep most reasonable combos from experiencing great loads.
|
|
|
|
Post by larry001964 on Mar 8, 2012 13:40:49 GMT -5
Ahhh ok I understand, thanks :-)
|
|
|
|
Post by sincitymopedryder2 on Mar 8, 2012 15:21:14 GMT -5
i boutht my vip that has a 47 mm piston in it i beleive its had it its whole life i got it at 2200km im at 9400 km now thats from late november to now and two weeks ago when i did a valve adjustment the rockers and everything still look brand new. when i first got the scooter it would take off real fast thought and go up to 7500 rpms in the low gear now it takes off alot slower and at about 5500-5900 rpms but its still quik then a stock 50cc and as soon as i get up over 50mph it has the same power as when i first got it i can ride at 25% throttle and cuise at 50mph and if i WOT at 50mph it will go until the speedometer needles all the maxxed and im zipping by cars like a motorcycle. but ya it still starts right up idles perfectly and ive never seen white smoke come the exhaust or engine area
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 8, 2012 16:02:30 GMT -5
What exactly is being overloaded ? anything over the maximum load rating listed in the vehicles specs is overloading. More weight makes the engine work harder which causes more heat and heat is the great destructor. I saw your posting on scootdawg stating your weight of 245. IMO your belts break from excessive heat caused by overloading. How do we fix this? I guess get a bike that has a higher load rating if you routinely put more on it than the engineers who created it designed it to handle. I ride my 82cc wide ass open all the time, I weigh 180lbs and my original gates belt lasted 1 year and would have gone longer but I saw one little area that was starting to fray so i put a new one on. I replaced my 1 year old variator yesterday because it was badly worn. I got back about 5 mph that I had lost compared to when I first built it to now. Now with the new vari and some 5.5g sliders its faster than it ever has been at 58 chino-mph. Currently 4056 miles and again my body weight is 180 lbs. 150s have the same belt just longer but 150s are designed for greater loads and thus have larger cooling fans and more cooling fin surface area to keep heat down. A qmb was not designed to have a stroker crank with a load just on the edge of or greater than the engine was designed for. IMO unless you get down to my weight you will continue to have problems with it especially if you run WOT. Again this is just all my opinion. i boutht my vip that has a 47 mm piston in it i beleive its had it its whole life i got it at 2200km im at 9400 km now thats from late november to now and two weeks ago when i did a valve adjustment the rockers and everything still look brand new. when i first got the scooter it would take off real fast thought and go up to 7500 rpms in the low gear now it takes off alot slower and at about 5500-5900 rpms but its still quik then a stock 50cc and as soon as i get up over 50mph it has the same power as when i first got it i can ride at 25% throttle and cuise at 50mph and if i WOT at 50mph it will go until the speedometer needles all the maxxed and im zipping by cars like a motorcycle. but ya it still starts right up idles perfectly and ive never seen white smoke come the exhaust or engine area Yeah A customer I have who is 5'2 and 110 lbs her 47mm motor that I put an #88 main, uni filter, raised the needle full, orange coil and cdi, stock 7g rollers and put a windshield on she claims it will bury the speedo past the 60mph mark on a flat road. With me on it it will only do 50 but I am 70lbs heavier. Her BF who is about 210 said it will only do 45 for him. Body weight has a great deal to do with the performance of such small motors. |
|
|
|
Post by larry001964 on Mar 8, 2012 17:48:39 GMT -5
If heat is causing this, heat dissipation can be delt with. If I posted 245 pounds ill have to find that post and correct it. I weight 220 lbs, ive never weighed 245, LOL.
Never had cvt heat problems when it was a 72 cc but its 15 mph faster now. thanks 1Fastqmb. That helps alot. :-)
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 8, 2012 18:21:32 GMT -5
If heat is causing this, heat dissipation can be delt with. If I posted 245 pounds ill have to find that post and correct it. I weight 220 lbs, ive never weighed 245, LOL. Never had cvt heat problems when it was a 72 cc but its 15 mph faster now. thanks 1Fastqmb. That helps alot. :-) the 'final numbers' you posted i could have sworn it said 245 but i just looked it says 230 but thats still a lot on a little 139qmb motor with a big 52mm bore and stroker crank with all the heat that creates. an oil cooler would be seriously helpful here . |
|
|
|
Post by larry001964 on Mar 8, 2012 18:47:16 GMT -5
Yea, during the winter I normally gain 10 pounds, but this job im pretty active and have not gained anything...
Ill look into the oil cooler, the colder temps I though it would be ok but I was wrong, first im going to add that extra base gasket, lower that compression a little, ill add the oilcooler at that point.
|
|
|
|
Post by 90GTVert on Mar 8, 2012 19:10:14 GMT -5
As far as CVT heat, I think it's beneficial to cool even a stock transmission better. On the 2Ts, some manufacturers actually started making covers with cooling vents. They are on the higher end minarelli knockoffs like the Polaris 50-70-90ATVs and such as well. Aside from heat affecting the belt, when they get really hot the springs, clutch and contra, just don't work the same. I noticed after long rides with soft clutch springs my clutch wasn't nearly as free and performance would get sluggish from RPM drop I associated with the contra losing a little stiffness from heat. Venting cleared those up for me. Rider weight breaking belts... ehhh... I dunno. I never broke belts at 300lbs on my GY6 80cc. Well, I did, but it only happened when I used the cheapest no name belts. They would snap on my 2Ts and 4Ts. Just junk IMO. All I had to do was go back to Bando belts and no problem. I was breaking belts on T1 doing 70+MPH around 300lbs... thought for a bit maybe it was weight related... but that came down to trans setup. I modded my pulleys in a way that stressed the belts in order to get all I could from it as far as speed. Went to a more normal setup and quit breaking belts, just lost a little MPH. I beat my scoots. Just posted burnout vids today. That's hard as hell on CVT stuff. If it's properly setup, I just don't think rider weight should bust belts. I might bust my belt, but my scoots are OK.  What would be really interesting to me would be some temp recordings on the same scoot with different riders. Would engine oil temp, EGT, CVT temp, etc... really show much difference? How about if we adjust the CVT to suit each rider weight best? We can really only speculate at this point. I swear I need a grant to ever try all the stuff I'd like to on scoots. |
|
