Spark Plug Heat Range

[Michael Stoic]

[forwarded from email]<br /><br />Dear Mr &quot;HONDA305&quot;,<br /><br />At this moment I am looking for information on the plug that must be fitted to the CB27 / CB77. The information that I have available is that there can be two types of plug fitted:<br /><br />1) NGK C7HW (or)<br />2) NGK C10H<br /><br /><br />If I follow the heatrange numbers there are 3 heatranges between them. Also the C10H is a very cold plug that is retracted (Spark 'inside' the plug)<br /><br />Now I have some questions:<br /><br />- What spark plug do you need in a standard CB77 ?<br />- Is there enough space in the for a plug that sticks approx 3mm inside the engine (Like the C7HSA) ?<br />- Is there an interchangeable spark plug for the NGK C7HW ?<br />- Is there also a Nippondenso plug recommended for this bike ?<br /><br />I know almost everything about (modern) spark plugs, but on the older bikes, I must be honest and say I am not so well informed. I hope you can help me with this.<br /><br />Best Regards,<br /><br />Michiel Vos<br /><br />Denso Europe B.V.<br />m.vos@denso.nl

[jesse]

here is a site that will bring you up to date on the ngk plugs.<br />http://www.kaila.net/tl125/tl125ngkcode.html<br />the 12 mm plugs that are used in the old honda engines are not available in some of the newer type plugs.you can find some plugs with 12 mm threads but too long of a reach.i have made spacers to put on the longer plugs and used them with good results,however i will say that if your engine is tuned and working properly the original plugs should give you good performace.if you want a hotter plug then a champion p7 or p8 will work.be carefull with the hotter plugs as they will self destruct if your bike is running lean and hot.

[Lee]

<br />[forwarded from email]<br /><br />Dear Mr &quot;HONDA305&quot;,<br /><br />At this moment I am looking for information on the plug that must be fitted to the CB27 / CB77. The information that I have available is that there can be two types of plug fitted:<br /><br />1) NGK C7HW (or)<br />2) NGK C10H<br /><br /><br />If I follow the heatrange numbers there are 3 heatranges between them. Also the C10H is a very cold plug that is retracted (Spark 'inside' the plug)<br /><br />Now I have some questions:<br /><br />- What spark plug do you need in a standard CB77 ?<br />- Is there enough space in the for a plug that sticks approx 3mm inside the engine (Like the C7HSA) ?<br />- Is there an interchangeable spark plug for the NGK C7HW ?<br />- Is there also a Nippondenso plug recommended for this bike ?<br /><br />I know almost everything about (modern) spark plugs, but on the older bikes, I must be honest and say I am not so well informed. I hope you can help me with this.<br /><br />Best Regards,<br /><br />Michiel Vos<br /><br />Denso Europe B.V.<br />m.vos@denso.nl<br />

<br /><br />NGK D8HS gapped at 0.018&quot;<br /><br />While I've never heard of a CB-77 with a 10mm diameter spark plug hole, assuming that is what you have, then an NGK C8HS spark plug should be correct. Gap them at 0.018&quot; and don't try to cross reference any other brand of spark plug.