honda xr 125 top end trouble

[bealesy78]

Hi guys ive recently bought a honda xr 125 (2003) which was in a bit of state when i got it, ran with little to no oil, air filter & box clogged with dirt, sprocket & chain worn etc.
Ive just had it serviced & worn parts replaced. It now runs a lot smoother but it seems to struggle at high revs & at top speed. It feels like theres more there but it doesnt want to go.
Anyone have any advice or where i should be looking?
Could it be the carb needs cleaning? Any help would be great thanks.
Cheers Lee

[flumpy7]

I'm no expert but if it ran with no oil I wouldn't be looking at the carb first. Compression test.
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2012 Sinnis apache

[flumpy7]

Also, how fast are you expecting it to go? It is a four stroke 125 after all.
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2012 Sinnis apache

[misscrabstick]

yes , it won't be a ball of fire in perfect condition, probably happiest about 55 to 60 mph?

[bealesy78]

The speedo's broke so dont know how fast ive been going since i got it home but i was following my dad after picking it up & he said we were sat at 60mph but it feels more like 50mph now if that.
I'm new to all this can you explain whats involved with a compression test & an idea of how much it costs please?

[flumpy7]

https://www.howtomotorcyclerepair.com/how-to-motorcycle-compression-test/

Obviously you need to get hold of a compression gauge. However, 50-60 is about right for your bike.
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2012 Sinnis apache

[Spangled]

Expect to sit at 55mph on an xr125, most mine's ever done is about 65 with wind behind me. I only weigh 9.5 stone too.

[workboots]

My xr 125 always felt quite over geared on the top end, if i still had it would most likely had a fettle with the gearing to help the engine rev better on the top end.

I would check the brakes are not binding, and also check and clean the carb.

In the hotter weather(?) i used a cooler spark plug, on really hot days the bike would lose power and not get above 50mph