Odd type noise

[Leotech]

Riding to and from Scarborough at weekend, GP200 ran great both ways, BUT, fairly standard motor, but with a 25 PHBL carb. As it got faster 60+ mph especially when accelerating it made a strange noise, like when you spin a bearing with a high pressure airline and eventually it gets so fast it stops itself. I'm going to say it wasn't any where near as aggressive as that noise, and it ran beautifully apart from that. The mains crank etc. are new, maybe 1000 -2000 miles max. I could almost make the noise come and go with the throttle position like on, off, on, off if I twisted throttle back and forth whilst it was making the noise. Any ideas what it could be? Anyone had owt similar? Or am I just listening too hard....... It's not pinking if anything its slightly rich.

[Adam_Winstone]

Dansi points flywheels make a strange whirring sound when the body starts to move on the boss. Any sign of independent movement of components?

[Leotech]

Not looked at anything yet, had a stinking cold since I got back. I gave it shake and glance when I got there but nothing was obvious.

[Fast n Furious]

Give your rear wheel a good rocking to see if your gearbox end plate has worked loose.

[Leotech]

Took gearbox out this morning, end plate had loose dowels but in the cast iron not the casing, swapped for a better end plate, one of the studs was stripped in the case so helicoiled that, and the needle roller on end of layshaft had one roller missing! felt much better in the wobble test with the rear wheel off the ground.


Noise exactly the same, Im beginning to think its kind of a rasping noise in the Ron Moss Ex Box, or maybe some kind of induction noise, as I can make it come and go with throttle position at same revs. In an act pf caution I put a bigger main in and it was still just the same.


Glad I looked in the motor though ref gearbox issues. I think ill just ride and listen less.

[hullygully]

is one of your exhaust springs vibrating?

[hullygully]

any news on this bud?

[Leotech]

Well, I went for a short test ride, and thrashed it up a hill and did a plug chop, just to rule out pinking, It looked fine but I put a bigger main jet in anyway and did it again. To my eyes and ears the jetting sounded pretty much spot on. I decided it was just a raspy intake noise echoing through the modified air box etc. I was on my way to a mates and I'd swap the main back to the smaller one and give it another thrashing and get a brew.

Just got onto the by pass and the flywheel side engine mount lug broke off the crankcase! So for now the GP is no more! Managed to ride it slowly to my pals and picked it up in my van. Since then it has languished in the naughty corner! A corner which needs extended as the TV200 , which has run flawlessly for 100's of miles, just spat its piston rings out of the exhaust port on Saturday! I hate scooters.

[hullygully]

STREWTH

[Rich Oswald]

Well, I went for a short test ride, and thrashed it up a hill and did a plug chop, just to rule out pinking, It looked fine but I put a bigger main jet in anyway and did it again. To my eyes and ears the jetting sounded pretty much spot on. I decided it was just a raspy intake noise echoing through the modified air box etc. I was on my way to a mates and I'd swap the main back to the smaller one and give it another thrashing and get a brew.

Just got onto the by pass and the flywheel side engine mount lug broke off the crankcase! So for now the GP is no more! Managed to ride it slowly to my pals and picked it up in my van. Since then it has languished in the naughty corner! A corner which needs extended as the TV200 , which has run flawlessly for 100's of miles, just spat its piston rings out of the exhaust port on Saturday! I hate scooters.

Bloody Hell!

[Scooterslag]

Well, I went for a short test ride, and thrashed it up a hill and did a plug chop, just to rule out pinking, It looked fine but I put a bigger main jet in anyway and did it again. To my eyes and ears the jetting sounded pretty much spot on. I decided it was just a raspy intake noise echoing through the modified air box etc. I was on my way to a mates and I'd swap the main back to the smaller one and give it another thrashing and get a brew.

Just got onto the by pass and the flywheel side engine mount lug broke off the crankcase! So for now the GP is no more! Managed to ride it slowly to my pals and picked it up in my van. Since then it has languished in the naughty corner! A corner which needs extended as the TV200 , which has run flawlessly for 100's of miles, just spat its piston rings out of the exhaust port on Saturday! I hate scooters.

Jeez!