Suzuki dr 125sm restricted????

[Gregstu88s]

Hi new to the group. I have just bought a suzuki dr 125sm 2009. The lad I bought it from had done nothing with it just commuting to and from work. The bike feels restricted and top speed is only 50mph and I know from every other person I've spoke to say it should at least 70mph. It's got a sport exhaust without baffles please help tia 

[Mississippi Bullfrog]

The exhaust may be the problem. Engines are often tuned to need a degree of back pressure from the exhaust.

 

Or it may just need servicing.

 

Check the gearing, if a previous owner has swapped sprockets thinking it will achieve higher speed they not have taken into account the low torque of a 125 engine. Usually dropping the gearing actually makes the able to hold higher speeds.

 

The engine is 12hp and known to be quite slow so 70mph is probably pushing it. But you ought to be able to hold 60mph on the flat.

[Gregstu88s]

Thanks I'll look I to it 

[stikflote]

It should do over 70 my nephew has one and he keeps up with my kawasaki 125 KRT

he also can stay with my Triumph at 70,as long as i dont screw it  and leave him

 

[Gregstu88s]

Has it got a after market exhaust at all mate? 

[Fozzie]

Is it one of these?

 

I borrowed one a bunch of times (like 11-12 years ago), and took it on the motorway. It was really hard pressed to get 65-70mph. It's a very sat up bike with no fairing, and you sit high on it, so you act like a massive wind barrier. Combined with the fact it only has 11BHP, you're in for a tough time!

How heavy are you? As at the time I was like 10-11 stone, I'm now about 14 so I'd never see the speed I did now.

 

I did find the valve clearances were out a fair bit, and it wasn't a high miler. So maybe you could check and adjust those? They are very easy on this bike. A fresh service, tyres pumped to the right pressure, and a good tail wind. You should manage at least 60.

[DR1]

I’ve just been watching a road test video for a Suzuki GSX R125 sports bike and its top speed was given as 72.5mph. It is fully faired and has the best power to weight ratio in its class. I doubt that a DR125 would come close. My DR175 was fine up to about 50mph but needed a lot of patience to reach over 60.

Edited December 24, 2021 by DR1

[stikflote]

Been talking to nephew he says he has had some tuning work done on his 

dr 125 and a different silencer ,he reckons  his top speed is now around 80mph,

i didnt know it was tuned  before we went   out in peak district.so thats how he kept up with me