Re: Suzuki GS150R

Thank you Freak inExile

Yes this is the first time i adjusted valve clearance. Only 4 free services were performed at SMK Suzuki Service center. Not sure if there were any tappet adjustments during the free services.
All other services/maintenance were performed at home or by a mechanic nearby. Mechanic or me never tried to do tappet adjustment before.
The bike was parked for a week for painting petrol tank mouth, underneath the tank, visible parts of frame, cleaning the water drain path in the tank, topping up battery water. I performed the adjustment after the engine was shut down for more than 10 days. So definitely a cold engine.


I will do that over the weekend and check for changes.

A scary incident happened after refitting the parts.
I almost set my bike on fire. After blown fuses, i could not guess the reason. I directly connected the battery without the fuse. All of a sudden, the wiring smoked with plastic smell. Asked my mom & wife to run out of the house. Switched of the engine and allowed the smoke/plastic burning smell to clear. Found that the wire from the horn to the wiring harness beneath the tank is severely burnt. The reason was I accidentally screwed the horn wire to the frame. Traced the wire and replaced it. Now the wiring is back to normal.

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Thank you rsk_Kelkar.

Yes the 'T' mark will appear twice. There was no play in the tappets during the appearance of T and after a 360 degree anti-clock wise rotation, the 'T' mark appeared again. This time, the clearance was what i mentioned in my previous post.

Will there be difference in the models ? Mine is probably the last batch of GS (August 2011 purchased) with the old headlight and body panels. It also has a different gear ratio, different number of tooth in chain sprockets and a smaller exhaust hole.

Re: Suzuki GS150R

From the symptom you mentioned I quite suspect the right TDC was not set.

For our 4-stroke engine Top Dead Center(TDC) will occur twice in one combustion cycle. i.e. you will be able to see the 'T' mark twice in once combustion cycle 1) at the end of compression stroke 2) at the end of exhaust stroke. You want to set your valve clearances at the end of compression stroke (When both valves are closed) and not exhaust (When exhaust valve might not be fully closed)

See four-stroke engine Wikipedia for a nice animation.

Try the entire operation again with addition of a small check as below:
1) Ensure 'T' mark visible in the magneto cover inspection window
2) Move the valve tappets by hand and notice the play
3) Rotate the crank by 360 degress till you see 'T' mark again
4) Move the valve tappets by hand and notice the play.
5) If the play in step 4 is more than that in step 2 continue with adjusting the gap to suitable value now.
5) If you feel play was more in step 2 than that in step 4, rotate the crank by 360 degrees again and continue adjusting the gap to suitable value.

Recommended valve clearances
Intake: 0.04-0.07 mm
Exhaust: 0.10 to 0.15 mm

P.S. Valve clearance adjustment should be done in cold state only.

Re: Suzuki GS150R

For the first time as in DIY or bike's service life?
Did you perform it on cold-engine(off for over say 5 hours)?
I assumed that clearances increase over period of usage/service. How come your's were so tight/close?

Intake : 0.05 mm
Exhaust : 0.12 mm
are nominal I suppose.

Ride the motorcycle for 20 kms to give it a proper warm-up then check for the noises.


@rsk_kelkar did it a few months ago.

Re: Suzuki GS150R

Adjusted the tappet gap for the first time in 44K Kms.

Input was changed from 0.04 to 0.06
Output was changed from 0.06 to 0.09

Now the noise seems to be increased. My bike sound like the timing chain has worn out all of a sudden.

My question: is 0.06 & 0.09 not an acceptable setting for GS ?

I made sure that the "T" mark was visible on the inspection window while rotating the crankshaft and also the tappets had some play (TDC of compression stroke).

Apart from the play, how do we ensure that the we are adjusting the tappet clearance during the compression stroke ? Any visible identifications on the cam chain sprocket ?

Re: Suzuki GS150R

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