runs better and throttles higher when intake is blocked

slawrus · 11-21-2013, 11:56 AM

I have a 2007 Roketa MC-17 150. It idles real well and starts easy, however dies at 1/2-full throttle. When I cover the intake on the back of the carb I can hit full throttle and runs like a beast. Is it too lean???

teddy554 · 11-21-2013, 03:33 PM

yes

slawrus · 11-21-2013, 05:20 PM

Valves are settings are spec as well with new fuel filter and vacuum system is not an issue either. I'm thinking maybe bigger jets or just replacing the carb all together. Anything I may have missed??

teddy554 · 11-22-2013, 01:09 PM

do You have the airbox hooked up, Just wondering why it became lean all of sudden.You can check the float to make sure it is working properly have you cleaned the carb

slawrus · 11-22-2013, 04:45 PM

Carb has been cleaned twice with cleaner and compressed air. Air box is hooked up as well. My diaphragm needle is at 1/2 setting. I wasn't able to see my jet sizes so if I order bigger I won't know the original. I live in Texas so elevation isn't really an issue. Might just get a new 26mm carb and replace gaskets and hoses. The way it's going it may be a complete rebuild but I wanna ride the damn thing!!

skuttadawg · 11-23-2013, 01:25 AM

I removed the lid off of the airbox on my 2T and 4T 50 for laughs . They both started up and were louder at idle but bogged so bad I did not leave the driveway . I would think you have a vacuum leak since it should do that unless you made a mod or have a bad vacuum hose . I would get a jet kit like this so you can fine tune your carb and save the larger ones in case you put on a Uni or K&N air filter or unrestricted exhaust pipe . Running lean will make it run hot and will damage the piston .

slawrus · 11-24-2013, 04:22 PM

Hey Skuttadawg, when you said ..."get a jet kit like this" was there a link to this said jet kit? I have a stock main jet and it looks like the #120 seems to be a popular size. I also plan on doing a uni filter too.

gitsum · 12-03-2013, 01:18 PM

Check for an air leak on the intake manifold and the airbox to carb hose?

slawrus · 12-03-2013, 10:28 PM

Okay so I re-jetted, added a uni and new stator, got rid of the PAIR, and secured my vacuum lines and now it runs like a freaking beast at WOT. Unfortunately while doing this I believe I burned up my VR cuz I had no electrical accessories pulling any power from the VR. Not worried though cuz it's a cheap fix and my engine is back in business.

11-21-2013, 03:33 PM	#2
teddy554 Join Date: Sep 2011 Location: staunton va Posts: 319	yes __________________ 2010 Cpi Oliver 70cc, naruku trans kit, downhill handle bars, tecnigas rsll pipe, s6 4g rollers, Vento R4 with 90cc 1e52qmf technigas next r 100cc pipe Naruku, 21mm race carb, s6 4.5 g rollers
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11-22-2013, 01:09 PM	#4
teddy554 Join Date: Sep 2011 Location: staunton va Posts: 319	do You have the airbox hooked up, Just wondering why it became lean all of sudden.You can check the float to make sure it is working properly have you cleaned the carb __________________ 2010 Cpi Oliver 70cc, naruku trans kit, downhill handle bars, tecnigas rsll pipe, s6 4g rollers, Vento R4 with 90cc 1e52qmf technigas next r 100cc pipe Naruku, 21mm race carb, s6 4.5 g rollers
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11-23-2013, 01:25 AM	#6
skuttadawg Join Date: Jul 2011 Posts: 127	I removed the lid off of the airbox on my 2T and 4T 50 for laughs . They both started up and were louder at idle but bogged so bad I did not leave the driveway . I would think you have a vacuum leak since it should do that unless you made a mod or have a bad vacuum hose . I would get a jet kit like this so you can fine tune your carb and save the larger ones in case you put on a Uni or K&N air filter or unrestricted exhaust pipe . Running lean will make it run hot and will damage the piston .
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11-24-2013, 04:22 PM	#7
slawrus Join Date: Nov 2013 Posts: 7	Hey Skuttadawg, when you said ..."get a jet kit like this" was there a link to this said jet kit? I have a stock main jet and it looks like the #120 seems to be a popular size. I also plan on doing a uni filter too.
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12-03-2013, 01:18 PM	#8
gitsum Join Date: Jun 2010 Location: southern Arizona Posts: 37	Check for an air leak on the intake manifold and the airbox to carb hose?
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12-03-2013, 10:28 PM	#9
slawrus Join Date: Nov 2013 Posts: 7	Okay so I re-jetted, added a uni and new stator, got rid of the PAIR, and secured my vacuum lines and now it runs like a freaking beast at WOT. Unfortunately while doing this I believe I burned up my VR cuz I had no electrical accessories pulling any power from the VR. Not worried though cuz it's a cheap fix and my engine is back in business.
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