Deviating from oem spark plug gap

[WindermereColvic]

Quick spark plug question for you..
I need to replace the NGK BR7HS - 10 in my Yamaha 5hp 2t , and can't find any for sale on a Sunday afternoon. I have got a new NGK BR7HS, which appears to be the same spec, but with a smaller gap. I've run the engine up in a dustbin, and the smaller gap seems to be working just fine.

Any reason I shouldn't continue using it?

I'm wary of adjusting the gap as I don't have any feeler gauges so might just break it..

Thanks,

Matt

 

[RichardS]

Quick spark plug question for you..
I need to replace the NGK BR7HS - 10 in my Yamaha 5hp 2t , and can't find any for sale on a Sunday afternoon. I have got a new NGK BR7HS, which appears to be the same spec, but with a smaller gap. I've run the engine up in a dustbin, and the smaller gap seems to be working just fine.

Any reason I shouldn't continue using it?

I'm wary of adjusting the gap as I don't have any feeler gauges so might just break it..

Thanks,

Matt

It won't be a problem if it starts and runs OK. It doesn't affect the heat capacity of the plug which is the thing which can cause problems. I often used to set the plug gap on old car engines slightly smaller than recommended to promote easier starting. The disadvantage is that a smaller gap can sometimes cause slightly rougher idling but if yours idles fine then it's all good.

Richard

 

[Big John]

Quick spark plug question for you..
I need to replace the NGK BR7HS - 10 in my Yamaha 5hp 2t , and can't find any for sale on a Sunday afternoon. I have got a new NGK BR7HS, which appears to be the same spec, but with a smaller gap. I've run the engine up in a dustbin, and the smaller gap seems to be working just fine.

Any reason I shouldn't continue using it?

I'm wary of adjusting the gap as I don't have any feeler gauges so might just break it..

Thanks,

Matt

Check this link:-

http://www.ngkntk.co.uk/index.php/technical-centre/spark-plugs/spark-plug-gap/

 

[David2452]

It will be fine short term but gap it when you can as it could whisker up faster with a smaller gap.

 

[VicS]

Quick spark plug question for you..
I need to replace the NGK BR7HS - 10 in my Yamaha 5hp 2t , and can't find any for sale on a Sunday afternoon. I have got a new NGK BR7HS, which appears to be the same spec, but with a smaller gap. I've run the engine up in a dustbin, and the smaller gap seems to be working just fine.

Any reason I shouldn't continue using it?

I'm wary of adjusting the gap as I don't have any feeler gauges so might just break it..

Thanks,

Matt

-10 after a NGK plug number indicates that it is supplied ready gapped at 1.0mm.

As David 2452 says set the new plug to the gap specified in the owners manual when you can. I think you may find it should only be 0.6 - 0.7 mm but you dont say exactly which year model you have

I dont understand, "I dont have any feeler gauges". Everybody has at least one set of feeler gauges surely ?


BTW the "R" in the number indicates that the plug has resistor suppression. B7HS ( which may be specified in your manual) is the same plug without a suppressor