Bike vibration

Hi,

I have a Suzuki EN125 (grey import) which, after changing the spark
plug, has been running well.

However, in the past month I have noticed a subtle change in
performance. All I can say is the engine sounds a little more strained
a say 6,000 revs than it did in the past. By “strained” I mean the
sound is like the screech when I used to rev up to 9,000. Previously
there was no “screech” at 6,000 revs. Also, the vibration has
increased. I can feel a buzzing through the handlebar grips, the seat
and the footpegs that wasn't there before. Finally, I sometimes feel a
“puffing” sensation on my calves which are about the level of the
carburettor when I am sitting on the bike. The bike acceleration seems
OK (it was never stellar) and the fuel consumption seems to still be
around 90mpg. These changes aren't dramatic but I have noticed them
and I'm just worried they might be early signs of a big failure
waiting to happen. Any ideas of things to look at or check?

Thanks

Clive

 

Give it a service. Change the oil and filter and check the valve
clearances. That might be all it is. Those little Suzuki OHC engines
are pretty tough. Have a squint round the engine with the engine
running, and the bike on its stand, just in case something is blowing.

 

I'd check the head/barrel bolts for tightness, and check the
head/barrel gasket area for signs of oil weeping, the carb to head
inlet rubber for leaking/tightness, the air filter and rubber inlet to
carb for leaks/tightness, and the exhaust for same.

What mileage has it done? They're pretty high-revving engines and need
to be serviced reasonably and regularly to keep 'em going well. Decent
oils and filters might help.

 

6,000 mile on 3 year old bike,

Complete oil and filter change a few weeks ago.

I used the correct 4-stroke, SL grade oil and a "genuine" Suzuki oil
filter.

I will follow the idea of running the engine while the bike is on the
centre stand and see what I can see.


Thanks

Clive