Loosing 5th gear

[Myguytubzy23]

Hi I'm on a 125 cc motorcycle and was wondering why my 5th gear has stopped working not massively bike minded but I can do basic work when I shift into 5th at about 50 55 ish the bike seems to go into gear but slows down to 40 mph and doesn't rise again unless I go down hill any ideas suzuki en125 2a is the bike btw

[TimR]

does the engine rev higher ?

i would guess clutch is starting to slip

[Mississippi Bullfrog]

It's not uncommon for 125s to not be able to hold speed in top gear as the engine torque isn't powerful enough. A lot of 125s are over-geared. When I ran a 125 I dropped the size of the front cog by 1 tooth for that very reason. It would then hold top gear above 55mph, otherwise it just couldn't pull in top and I was always flicking up and down the gears.

[JackieOWheels]

My CBR125 has that problem too, when I'm gear up the bike drops speed too and when I drop down a gear when I'm at that speed, the rev counter is almost red lining on 4th. It usually only happens if I am not doing a smooth acceleration or if I forget what gear I'm in (my bike is that old). Generally if I gear up smoothly and the road conditions are good, the speed will go up without dipping when I go up the gears.

[Bender]

Lack of power would be first thought, you need to really rev it before dropping into 5th

[fastbob]

I'm afraid I'll have to agree with that , sounds like it just hasn't got the beans to hold fifth gear .

[Breadsnapper]

Try removing the egr valve if you have one. When I had a 125 I removed mine and found the engine revs better in higher gears, top speed increases and would hold speed so I didn't keep having to drop down to 4th.

Dave.