hi

im a bit confused with what spak plug to put in my bike it has in it now cr6hsa which we think has been in their since new and it need's replacing. i was told that their are a number of spark plugs avalible for the ybr for example the one i have in it now is apparently meant for slow inner city driving (or its better at it), but i was told their is another spark plug that is better for higher speeds e.g. A roads. from what i could find on the internet it pointed to the NGK C7HSA for this so i went and brought it but now it comes to putting it in the bike and i am worried that it will cause it damage. if annyone could clear this up it would be greatly appreciated.

thanks conor

(sorry for spelling mistakes its not my strong point)

Its just the temperature range of the plug. Heat causes resistance that causes heat etc. The resistance reduces the spark energy.

The 6 plug will run fine but will be ideal at the city stuff and give easier starting.

The 7 may cause a little harder starting but should give a cleaner burn on higher speed stuff.

Thats the theory. To be honest, i doubt you will notice. Certainly wont harm the bike.

thankyou very much i was just a bit worried it may damage the bike but it obviosly wont thanks again!

Nah. Go from a 6 to a 9 and it will get more of a problem. But still only how it starts and throttle response etc.

I have a YBR and i had the same thaugh as you, so i stuck a cr7 in set witht he correct gap (according to the manual) and the bike didnt agree in the slightest. would take me 10 minuites to start it, then i wasnt able to acheave over 6000 RPM. as soon as i put the 6 back in it went back to how it was before. it may just me my bike bieng tempremental, but i just thaught id share.

So harder to start. And ultimately different spark characteristics at higher speeds.

With such a dramatic effect of such a subtle change you might want to give the bike a once over. Check filters and valve clearances etc. 1 step up should not really affect it that much.

I found that too, put a CR7HIX in and it made the engine knock, so I've gone back to the normal CR6HSA and its a lot smoother. One thing I've found though is changing the rubbers on the spark plug cap and giving the HT lead a good going over with silicon oil made it a bit smoother when it was wet, not so much now its starting to dry out but still worth a go.

at the time i changed the plug i changed all filters, gearbox flush + new oil, new HT cap and valve clearances and i got shit performance. as soon as i put the old CR6HSA back in as a retrace to try and locate the problem, it was running better than before the mini service.

Still a surprising effect. Esp as its a reccomended option.

Out of curiosity. Was the poor performance in the cold weather we have finaly cleared (he says touching wood).

If the engine temp is v low the engine will perform badly. Just as the 6's performance would drop on a hot day.