Suzuki GZ125HS Sluggish acceleration, useless top speed.

[asharin]

Before I start I'll just say I do know not to expect too much from a 125 cruiser, but this one is a little slow even for that

I recently picked up a Suzuki Marauder Gz125HS for a cheap ish price. It's been sat a short time not doing much but otherwise looks sound.

Took it out for a test ride, seemed okay aside from sluggish acceleration (I put that down to it being cold) Of course I didn't get out of a 40mph zone on the test ride..

Went for a proper ride on it today it accelerates VERY slowly and the best speed it can manage is 50mph...and it took nearly half a mile to get there. That isn't right, even for a GZ125 I've ridden a friends before, and while it didn't set any records, it accelerated a lot faster than mine, and could get 60 (JUST)

Any ideas what it could be causing it to run so badly?

I changed the spark plug already, air filter looks clean, changed the oil and oil filter and drained the carb in case it had water in the bottom.

Unless anyone else has any ideas the only thing that springs to mind is giving the carb a good clean, however I've never done that before, is is hard?

Edited December 7, 2012 by asharin

[asharin]

Oh yeah, I should add, it starts up and idles just fine.

[eastanglianbiker]

has it got an in line fuel filter if so change it,have you filled it up with fresh petrol i assume you have if so it might well need a carb clean out and no its not to hard a job to do worst bit is removing it from the rubber boots each side

[asharin]

Don't believe it has an inline filter, but will go check after lunch

Yes, fresh fuel.

[Joeman]

not been adding any dodgy fuel additives have you???

http://themotorbikeforum.co.uk/viewtopic.php?f=5&t=46460

[Tango]

You've not got binding brakes? If the bike was stood for a while....

[asharin]

They don't feel like they are binding, not having any issues pushing the bike They work okay when I used them too.

No inline fuel filter either, though I may add one once I get it all sorted.

[Tango]

Check valve clearances as if they are some way out it can affect the performance of the bike.

[eastanglianbiker]

also check plug gap as that can affect running or replace it

[asharin]

Already changed spark plug, said so in first post

As for Valve clearances, how do you do that? I looked at one guide and was confused after 1 paragraph

[Tango]

For the valve clearances you'll be better off if you get a Haynes manual for the bike if it's available.....not a difficult job, but you need to know what the clearances should be and how to set the piston to top-dead-centre (TDC). I'm guessing that engine will have Tappet type adjusters instead of bucket and shim.

Although you've changed the plug it may be worthwhile just checking that it's the right one for your engine......another thing you can find out from a Haynes manual or owners handbook.....

[Fozzie]

Its what I thought... Seen a YZF slow from its top speed of 84mph to 66mph because its valves were out. Its a regular adjustment to make on 125s

[Zod]

You probably wouldn't expect to get much acceleration out of them anyway, Marauders are a bit heavy which is probably one reason why it is slow on acceleration plus it could also be due to chain tension could probably be rear wheel alignment or rear wheel related.

I have ridden one before and didn't get much acceleration out of it, then I tried out a mates Intruder and didn't get much out of that one either.

[Waynetavit]

Check that the sprockets haven't been swapped out, Wayne.