{"id":10348,"date":"2024-11-20T01:00:00","date_gmt":"2024-11-19T16:00:00","guid":{"rendered":"https:\/\/www.decoboco.info\/en\/?p=10348"},"modified":"2026-09-24T13:46:22","modified_gmt":"2026-09-24T04:46:22","slug":"gpz550-newsletter-11-20-how-are-you-engine-compression","status":"publish","type":"post","link":"https:\/\/www.decoboco.info\/en\/20241120\/unclassified\/gpz550-newsletter-11-20-how-are-you-engine-compression","title":{"rendered":"GPz550 Newsletter 11\/20. “How are you doing~?” I checked the engine compression (phew, all good) Going to change the spark plug heat range from 9 to 8 (*’\u03c9’*)"},"content":{"rendered":"
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Should I check the engine compression? Or shouldn’t I? I’m torn about it.
After all, humans tend to “get shocked when numbers are low” <\/strong>don’t we… <\/p>\n\n\n\n

If it’s solid, that’s reassuring, but if it’s low…
you end up thinking maybe I should tear down the top end… right? <\/p>\n\n\n\n

Oh, and with older bikes, the valve clearance can get tight, and
“the valve won’t close properly” <\/strong>which can subtly happen. Checking compression is actually perfect for catching that kind of thing too.
The manual might say to check it at operating temperature!
But I usually check it cold when it hasn’t expanded yet.
If it’s solid when cold, the operating temperature should be fine too?

Anyway, if the numbers come out solid, that’s exciting… fingers crossed
“Throttle wide open! Battery fully charged!” <\/strong>I spun the starter motor. <\/p>\n\n\n\t\t

\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\t\"\"\/\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\tKawasaki Genuine Fuel Gauge 52005-1025 for GPZ550\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t
\u682a\u5f0f\u4f1a\u793e\u30d2\u30ed\u30c1\u30fc\u5546\u4e8b \u697d\u5929\u5e02\u5834\u5e97<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\u00a59,256\t\t\t\t\t\t\uff082026\/09\/15 21:33\u6642\u70b9 | \u697d\u5929\u5e02\u5834\u8abf\u3079\uff09<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tAmazon\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tRakuten\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tYahoo!\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\"\"\n\t\t\t\t\t\u30dd\u30c1\u30c3\u30d7<\/span>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\n\n<\/a>\n\n\n\n\n\n\n
<\/div>\n\n\n\n

In the end, all the numbers were reassuring (*’\u03c9’*) <\/h2>\n\n\n\n
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#1<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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#2<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n
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#3<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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#4<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

All cylinders 1 through 4 showed stable numbers overall, which was reassuring.
If even one was extremely low or the spark plugs were covered in oil, that would be disappointing, right?

I don’t know what the future holds, but for now it feels like we’ve cleared the first hurdle.
With oil-cooled bikes this almost never happens, but
with Z and GS models and such, there are rare cases where valve clearance gets too tight.
If you can’t get clearance even with the thinnest shim, you have to remove the head,
and you’ll need to check the valve and valve seat too.

Finding out about something like that before you even ride would be a bit disappointing, wouldn’t it?
It’s definitely better to check, but “bad numbers are disappointing” <\/strong>so
I’d rather not check compression if I can help it.
Anyway, this time I got to see good numbers and feel reassured. <\/p>\n\n\n\n



<\/p>\n\n\n\n

I’m going to drop the spark plug heat range from 9 to 8 (*’\u03c9’*) <\/h2>\n\n\n\n
\n
\n
\"\"<\/figure>\n<\/div>\n\n\n\n
\n
\"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n

The standard setting has a DPR9EA-9 installed, but I’m changing the heat range to 8.
Since I’m not going to be hammering it on the highway at full throttle, I don’t need such a high heat range.

It’s good to match the spark plug heat range to your riding conditions,
so it’s fun to experiment with different options.
Being able to adjust spark plug heat range like this is actually one of the perks of owning a classic bike.

When you try different wear parts that make a noticeable difference,
the bike’s character really shines through and becomes more truly yours. <\/p>\n\n\n\t\t

\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\t\"\"\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\tNGK General Spark Plug (Screw Type\/Terminal-less) 1 Piece [4929] DPR8EA-9\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t
\u65e5\u672c\u7279\u6b8a\u9676\u696d(NGK)<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\u00a5536\t\t\t\t\t\t\uff082026\/09\/21 03:35\u6642\u70b9 | Amazon\u8abf\u3079\uff09<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\"\"\n\t\t\t\t\t\t\t\u53e3\u30b3\u30df\u3092\u898b\u308b<\/span>\n\t\t\t\t\t\t<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tAmazon\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tRakuten\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tYahoo!\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\"\"\n\t\t\t\t\t\u30dd\u30c1\u30c3\u30d7<\/span>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\n\n<\/a>\n\n

The article was not found.<\/p><\/div>","protected":false},"excerpt":{"rendered":"

Should I check the engine compression? Or shouldn’t I? I’m torn about it. After all, humans tend to “get shocked when numbers are low” don’t we… If it’s solid, that’s reassuring, but if it’s low… you end up thinking maybe I should tear down the top end… right? Oh, and with older bikes, the valve clearance can get tight, and “the valve won’t close properly” which can subtly happen. Checking compression is actually perfect for catching that kind of thing too. The manual might say to check it at operating temperature! But I usually check it cold when it hasn’t expanded yet. If it’s solid when cold, the operating temperature […]<\/p>\n","protected":false},"author":2,"featured_media":10342,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"pochipp_cv_data":"{\"c6ef6dcc\":{\"pv\":1293,\"imp\":1103,\"clickedOther\":8,\"clickedAmazon\":1,\"clickedYahoo\":1},\"a57849b6\":{\"pv\":1293,\"imp\":998,\"clickedAmazon\":2}}","swell_btn_cv_data":"","footnotes":""},"categories":[4],"tags":[],"class_list":["post-10348","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-unclassified"],"_links":{"self":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/posts\/10348","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/comments?post=10348"}],"version-history":[{"count":0,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/posts\/10348\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/media\/10342"}],"wp:attachment":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/media?parent=10348"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/categories?post=10348"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/tags?post=10348"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}