250 Scoot wont go over 45 now!!

[ChipUK]

Hi Folks

Been having a bit of trouble with my 250 Majesty scoot. Really bad idle problems. Had a super Bike mech out to it a few weeks go and we gave it a thorough overhaul. Front and rear brakes, new belt and rollers. Took it out and it ran lovely apart from the idle problem.

Not had much time to mess with it so sat idle for 3/4 weeks. Took the seat and everything off again (arrrgh) and put in a new auto choke, reset the carb. Got it idling lovely. Put some heated grips on and new battery and took it out. Runs great......apart from the fact it wont go over 45mph now! What am I likely to have done to cause this?

Chip

[Nobby the Bastard]

[ChipUK]

[stevo as b4]

Sounds like the variatior isnt moving it's full travel since you did the belt and rollers.

I'd be checking the new and old parts to make sure they are the same, the roller weights and that nothing is stopping the pulleys from moving freely.

It won't be a carb, brakes or engine problem if it's running ok otherwise and not spluttering or failing to rev.

[ChipUK]

Thanks for that. I did run it after the belt and roller change and everything was fine. It ran it to full speed. The problem has only surfaced since the idle was fixed

[cb1rocket]

Check the new choke isn't sticking. Does it sound rough at 45?
____________________
Honda H100S2 Rebuild - https://www.bikechatforums.com/viewtopic.php?t=253852

[P.]

Why did you reset the carb? If it was fine... and you decided to touch it, then its something there. Nobby was right.

[-]

[craigT19]

Hi,

The carbs on the 250 Maj were always abit of a pain in the arse.

Its a long shot but off the top of my head you will hit 45 on one of those at about half throttle and from memory i had a similar issue with a customers majesty which turned out to be a hole in the diaphragm stopping the carb from opening up fully . But that particular customer hadnt touched the carb them selves.

As said above the problem wasnt there before the chock change but is after so u have almost certainly upset the carb. I second the above as far as taking it off, strip it, clean it, back to factory settings and then try it.

Good luck
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[bassmastergen...]

What they all said - find the factory settings for the carb and put it back to how it should be.

I'm not familiar with that carb - is the auto choke one of those electric bi-metallic strip things that Honda liked using in their scooters in the '80s? If it is, and you've replaced it with a Chinese one don't assume that it will work just because it's new! I know this from experience...

If cleaning and resetting the carb to factory settings doesn't work, I would put the old bystarter back on and see what that does.

[Nobby the Bastard]

[ChipUK]

Thanks for all the replies guys. Really appreciated.

It would be useful if some of you read the posts accurately before posting your masculine vitriol but thanks to those with a little more empathy.

I will do as some suggest and check the carb over and yes - I am up to it Nobby know all et al

Chip

[Nobby the Bastard]

[-]

[bikenut]

Hi,

The carbs on the 250 Maj were always abit of a pain in the arse.

Its a long shot but off the top of my head you will hit 45 on one of those at about half throttle and from memory i had a similar issue with a customers majesty which turned out to be a hole in the diaphragm stopping the carb from opening up fully . But that particular customer hadnt touched the carb them selves.

As said above the problem wasnt there before the chock change but is after so u have almost certainly upset the carb. I second the above as far as taking it off, strip it, clean it, back to factory settings and then try it.

Good luck Thumbs Up


I don't know this bike, but, if as above says, and the carb is the diaphragm cv type, then a punctured diaphragm would give the lack of performance indicated, just like the old days of Stromberg car carbs, remember them ??

So, chip, make it possible to see the carb intake and the piston therein.

Using your finger or similar with the engine off, gently push up the piston. There may some light resistance and some hissing, but did it go up all the way ?? and drop down all by its self ???

Yes is a good sign.

Next, start the engine and gently increase revs, did the piston rise, and rise further with more throttle ??

No, then a punctured diaphragm ( or air leak problem, but most likely a diaphragm problem. Was the diaphragm fitted correctly and able to rise and fall freely ? )

Hope its not summut daft like a rag under the saddle

Will try and post a diaphragm type cv carb for you so you know what a basic one looks like, and what's involved.

Get a manual, which always helps.

You know of cmsnl for the exploded views ? you do now ! :D :D :D
____________________
nuts about bikes

[bikenut]

Out of interest, I cant spell curiousity correctly, I have just visited cmsnl and picked the first Majesty model in the list.

I now know that this bike has disc brake on the front, a cdi ign system, is a 4 t, the carb is a diaphragm cv type with a replaceable diaphragm, and how the variator goes together, and that's just after a few seconds glance.

So chip, go forth and see.

cmsnl copy and a paste to here didn't work for me, but it is possible to do.
____________________
nuts about bikes