HELP! YP125 Majesty Flat as a Fa*t

Message

Jasper · #1 Unread post by **Jasper** » Sat Jan 21, 2006 5:30 am

Firstly Hi to all Newbie hear!

Is there any body out there that can help me with a problem with a Yamaha YP 125 Majesty scooter,year 2000 with 19000miles.
Just bought it and it's as flat as (Why did you buy it then? I didn't somebody bought it on my behalf with out testing it!) Although I've had bikes all my life (last 25 years) Don't know anything about these machines,Painfully slow averages 30mph and will touch 40 on the flat or down a hill.

Have tried everything.
Starts OK,Doesn't smoke or splutter,air filter ok,new plug,Cleaned the carb,replaced diaphragm (£90)I don't think that it's the clutch because it doesn't rev out.That's the problem it doesn't seem to want to rev-Sort of as if the brakes were stuck on (Which they aren't).I know it's a scooter but am I really asking too much?
Can anybody tell me at least how fast it should do?

Cheers in advance any help welcome before I pull all my hair out!!!!

Jasper

txbadboy · #2 Unread post by **txbadboy** » Sat Jan 21, 2006 7:45 am

well its obviously a 2-stroke...isnt there a mixture setting even on 2-strokes? is there a strong smell of gas while its running? because if its running rich, that will really diminish the power. right now, my bike AND my truck are running rich. so its a strong smell, diminished power, AND decreased gas mileage...but ive just not found the will to get off my "O Ring" and fix it, haha.

but you might check the mixture settings on your carburetor. you replaced the spark plug, but did you gap it correctly?

thats all that comes to mind at the moment..good luck.

Jasper · #3 Unread post by **Jasper** » Sat Jan 21, 2006 8:25 am

No! It's a 4 stroke.

Thanks for your reply all the same.

Jasper · #4 Unread post by **Jasper** » Mon Jan 23, 2006 12:48 am

Well is that it?
No one got any ideas?

Any one at least tell me how fast this thing should go?

txbadboy · #5 Unread post by **txbadboy** » Mon Jan 23, 2006 8:27 am

i dont think ive ever heard of a 4stroke 125...either way, that would explain its slow speed to me. generally speaking, 2 strokes produce more power (of equal engine sizes) so the fact that your 125 is a 4 stroke, i wouldnt be surprised that it didnt get over 30 mph.

BuzZz · #6 Unread post by **BuzZz** » Mon Jan 23, 2006 8:41 pm

I'd find someone with the same scooter and trade a ride with them. Then you'd know if yours was down on power compared to his or not....

Jasper · #7 Unread post by **Jasper** » Mon Jan 23, 2006 9:11 pm

I had thought of that one but living in rural France there's not too many about!

TechTMW · #8 Unread post by **TechTMW** » Mon Jan 23, 2006 9:42 pm

Hi Jasper, welcome to the Forums. Your Yamaha Majesty 125 should be able to reach 65mph (~100 kph.)

You seem to have covered all the bases with your initial service.

It seems like a diaphragm problem to me, but as you have replaced the diaphragm, I don't know what to tell you. Is it possible that you have purchased a restricted model? Is the slide moving freely in the carburettor?

Jasper · #9 Unread post by **Jasper** » Mon Jan 23, 2006 11:01 pm

Hi there!

I have also done further research and 4 stroke 125cc scooters should do as you say 65/70mph.
I replaced the diaphragm as the old one was brittle and holed and was 100% sure this was my problem.

I have had the exhaust off and that's not restricted!

To no avail,is there a special way of changing the diaphragm/testing which by the way holds the needle slide which obviously is not working correctly could cause my problem?

I also note that I think that the bike has been stood for a year or so.

I will take air filter off and with a mirror try and see if it's opening correctly with the throttle open on the centre stand,failing that carb in bit's for the 10th time and will let you know how I get on.

Jasper · #10 Unread post by **Jasper** » Wed Jan 25, 2006 7:09 am

I decided to strip the carb (again) down to it's last little nook and cranny and soak every thing but before doing so I took the air filter box pipe off and under further inspection realised that the slide that's operated by the vacuum diaphragm was not opening properly when revved, just sort of nervously twitching and closing again.

Everything cleaned again blown out and back together paying special attention when fitting the diagram.

And guess what?

Sorted-It's a totally different machine,revs and excelerates up to 70 mph no problem.

Well chuffed as I've had my head round this one for the last 2 months.Conclusion being that it was either the passage that creates the vacuum was blocked or the diaphragm that wasn't fitted correctly in either case it was the non functionment of the diaphragm that was causing the problem!!