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Messages - jmoak80

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Grandvista 250 / Re: accelerating from 20mph to 45mph
« on: May 23, 2016, 10:12:06 PM »
Indeed, high speed fuel delivery was the issue. I got a new diaphragm with the air slide attached and installed. It worked. Thanks for the tip about the grease, it made the diaphragm stick perfectly into the grove, and installing the spring and brass cap was very simple.

When i carefully took the cap off of the carb i noticed that the old diaphragm was slightly out of alignment and kinda stiff, that put a smile on my face. What is odd is that high speed fuel delivery wasn't a problem before the carb got gummed up. maybe me cleaning it all out and messing with it caused it to get noticeably erratic and bad, then subsequent cleanings caused it to fail outright-- just  a thought.

Once i installed the new part i noticed that the slide had much more resistance when i pushed it up and let it go, that too put a smile on my face.

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Grandvista 250 / Re: accelerating from 20mph to 45mph
« on: May 12, 2016, 04:37:49 PM »
I would say that the bike does very well getting to 35 mph. the power tops out at 45-50 mph running flat ground at about 5-6k rpm. it doesn't act like it is out of gas rather the power just tops out, like i need more throttle or something.

There is no noticeable improvement what-so-ever.

It idles great. nothing uneven. it does for time-to-time load up and stall from idle when i get on it but that is very rare.

I never took the pilot screw out and cleaned after the bike had been sitting with bad gas. I will fiddle with it sometimes this week. keeping my fingers crossed..

- If this doesn't work i would definitely love to purchase an oem carb, especially since it is not on my dime. I can be the hero for money. yay!

thanks again for your tips, they are greatly appreciated.

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Grandvista 250 / Re: accelerating from 20mph to 45mph
« on: May 11, 2016, 11:38:51 PM »
I still haven't figured out what the throttle hesitation issue is. I pulled the carburetor out again and throughly cleaned the main and secondary jets. I also tested the diaphragm by attaching a vacuum to the outlet of the carb. With the carburetor out i turned the vac on and actuated the throttle body, sure enough the gate lifted proportionally to the amount of throttle i gave it. I know this test might not be entirely accurate because the amount of vacuum might have been too much giving me the impression that the diaphragm is 100% operational  and not leaking but it did offer some piece of mind. I ordered a new diaphragm anyways and i will install when received. My next line of attack might be the fuel pump, it could be slow. I know in the manual it specifies an certain amount of fuel (maybe 14cc in ten sec). It could be a faulty fuel pump or an undersized fuel filter (that test should confirm). i will keep everyone posted.

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Grandvista 250 / Re: accelerating from 20mph to 45mph
« on: April 27, 2016, 11:40:03 PM »
I checked the entire vacuum tube system with water, i'm not seeing any leaks anywhere. The spark plug looked fine. The scooter isn't giving me much power anymore at higher speeds. it used to sort of take off sporadically between 20 and 45mph. now it gradually gets up to 50-55 (takes like 30ish seconds ) and doesn't really want to break that speed. The vacuum chamber falls rapidly when you push up but does make a faint slurping sound. So i guess i'm going to find the rebuild kit and tackle that next. I have the repair manual, for whats it is worth. do you think this is the proper plan of attack? Any help would be greatly appreciated.

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Grandvista 250 / Re: accelerating from 20mph to 45mph
« on: April 07, 2016, 08:15:27 PM »
Thank you for the response. I will perform the tests as described. I will keep you posted i promise. Thank you again.

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Grandvista 250 / accelerating from 20mph to 45mph
« on: April 07, 2016, 12:28:24 AM »
Hi all,
I have searched this forum a bit and i haven't really found anything about my issue. I'm a newbie and i love this forum, ya'll are great help. Thanks in advance

I have a GV 250 that i recently cleaned the carb on (old gas). I saw the video posted sometime ago by another user and it was great info. When i got it back together it started and revved and runs fine however it is slow getting up from 20 to 45 mph. it has good acceleration to 20 mph and sometimes i can feel it kick me up to 50+mph no problem but most of the time it takes 15 seconds or so to get to 45 then it really wants to go 60+mph.

I was thinking a couple of things. Maybe i got carb cleaner in the diaphragm intake, this causing the carb diaphragm to slow and/or act erratically. Maybe the accelerator pump is clogged (i confirmed it was unclogged when i put back in, but you never know) maybe the drive belt is worn or slipping?

Has anyone ever had a problem like this?
any help would be greatly appreciated. thanks you

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