|
|
Post by loganhes on May 31, 2009 22:51:27 GMT -5
I fairly recently upgraded my 2007 Roketa Maui with a 72cc big bore kit. I however am not real pleased with the speed that I am achieving. I can max out at around 41 mph, but it takes quite some time to get there. I have a lot of trouble getting up hills. I tried swapping out my 6 gram rollers for 8 grams and it only got worse. I recently cleaned out the car. and put in a #88 jet and it did not make a difference. So... i was thinking of installing a larger carb. So my question is...does anyone have any idea what size carb. is in my Roketa Maui? and also what larger size carb. could I get and where could I get one?.....Jeremy? Below is a list of what I have done to my scoot so far. By the way...I weigh around 200lbs. Any help or suggestions would be greatly appreciated.
72 cc big bore kit
high performance CDI
UNI foam filter
high performance coil
iridium spark plug
6 gram Dr. Pulley sliding rollers
#88 jet
MRP exhaust
kevlar belt
|
|
|
|
Post by Rebel on May 31, 2009 23:40:30 GMT -5
Tell us a little more about how it is running. Does it seem to have any problems with not pulling well in a particular rpm range? Does it come off the line well then drop off?
The things you listed seem to be the formula to get it up to speed.
|
|
|
|
Post by harrywr2 on May 31, 2009 23:45:37 GMT -5
Tunability will go to the %%#@_%@%.
IMHO their is no point in having a carb that is significantly larger then the intake valve. It's a basic plumbing issue...an 18 mm carb is basically a 3/4" pipe...why have a 1" carb.
|
|
|
|
Post by d3adeyes on Jun 1, 2009 6:56:09 GMT -5
i may be wrong but wouldn't the heavier roller weights cause the scoot to lose power going uphill? and also cause it to take longer to get up to speed. but would in turn increase the overall speed.
|
|
|
|
Post by loganhes on Jun 1, 2009 8:22:17 GMT -5
Tell us a little more about how it is running. Does it seem to have any problems with not pulling well in a particular rpm range? Does it come off the line well then drop off? The things you listed seem to be the formula to get it up to speed. Well...from time to time it seems to hesitate when you first start moving. Once moving it runs nice and smooth but it just accelerates very slowly and takes a long time to finally reach 40 mph and this is only on a perfectly flat road. One think I did notice is that as soon as I installed the MRP exhaust the scooter started backfiring when I let off the throttle. It never did this with the stock exhaust. Is it possible that this is the cause of my lack of power? Perhaps I should re-install my stock exhaust? I have two hills that I have to go up to and from work. The scooter goes so slow up these hills that I have to pull over to the very side of the road and let cars pass. I am very frustrated!!!! |
|
|
|
Post by kuzikood on Jun 1, 2009 9:03:47 GMT -5
back fires when ya let off the throttle ? double check there is no leak between exaust pipe and head that back fireing sounds like the exaust gasket is blown out making ya run wayyyyyyyyyyy to lean
|
|
|
|
Post by loganhes on Jun 1, 2009 9:19:06 GMT -5
back fires when ya let off the throttle ? double check there is no leak between exaust pipe and head that back fireing sounds like the exaust gasket is blown out making ya run wayyyyyyyyyyy to lean Kuzikood, That was one of the first things I did. When I bought the MRP exhaust it did not come with a gasket and I therefore thought that one was not needed. However when it started to backfiring when letting off the throttle I cut my own fiber gasket and installed it. The backfiring is still happening though. |
|
|
|
Post by kuzikood on Jun 1, 2009 9:26:02 GMT -5
did it backfire imediatly or later down the road ?
|
|
|
|
Post by loganhes on Jun 1, 2009 11:22:16 GMT -5
did it backfire imediatly or later down the road ? The backfiring did not resume right away after putting in the gasket, it was a few days later. I then removed the exhaust and checked to see if the gasket was still there and it was. |
|
|
|
Post by Rebel on Jun 1, 2009 11:37:53 GMT -5
Try a crush ring for your exhaust instead of a gasket.
|
|
|
|
Post by loganhes on Jun 1, 2009 11:43:30 GMT -5
Try a crush ring for your exhaust instead of a gasket. Any idea where i can get one?....perhaps Jeremy has one in stock?...I will contact him. |
|
|
|
Post by scootermike on Jun 14, 2009 13:01:15 GMT -5
Gaskets have crush rings built in at last ones I have plus we have crush rings, when adding more gas add more air, large head has to be added also, 6 gram is best all around 8 gram robbs all take off and hill climbing, performance variators have better ramps that get you going clutches and bells and belt play a huge part, an 88 jet is not large enough most stock are 85, more air in more air out more power MRP pipes  ? |
|
|
|
Post by harrywr2 on Jun 14, 2009 15:05:59 GMT -5
|
|
|
|
Post by Enviromoto on Jun 15, 2009 7:50:28 GMT -5
Scootermike is right I would go with a 95 main jet and see where that gets you.
|
|
|
|
Post by scootermike on Jun 28, 2009 11:26:24 GMT -5
Adding jets do help and yes there auto choke carbs up to 21mm OKO for 139 engines and they work plus its very easy to add a manual choke carb. You can also open up intake on head.
Trying different size air intake makes a difference for back pressure which affects gas flow. Example, a dual layer UNI will hold back pressure like stock box, a Uni Pod will add more air and might not do as well. The length of an air intake from carb to air filter can make a difference. Stock scooter with air filter upgrade may need the air tube from stock box to keep back pressure.
Your gas and air flow are very important. A good running scooter with 47mm kit should go 45 easy.
|
|
