{"id":34875,"date":"2021-03-27T23:11:14","date_gmt":"2021-03-27T14:11:14","guid":{"rendered":"https:\/\/www.decoboco.info\/en\/?p=34875"},"modified":"2026-09-24T13:45:41","modified_gmt":"2026-09-24T04:45:41","slug":"air-cooled-gpz750-gpz750f-inspection-oil-change","status":"publish","type":"post","link":"https:\/\/www.decoboco.info\/en\/20210327\/everyday-events\/air-cooled-gpz750-gpz750f-inspection-oil-change","title":{"rendered":"Did Rainey love it too? Air-cooled GPZ750\/GPZ750F. Inspection, oil change, MOSFET regulator & Shorai battery mounting, tank mounting improvement, fluid exchange and more"},"content":{"rendered":"
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The machines that WGP riders rode in their younger days still seem to shine today.
From the superbike 1000cc era down to 750, from air-cooled to water-cooled, from half-fairings and bikini fairings to full fairings\u2014they’ve changed so much.

Maybe they held big dreams about ordinary bikes that were actually being sold, you know?
Anyway, let me start with the fabricated parts. <\/p>\n\n\n\n\n\n\n\n

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Everyone installed it at home under their bike, but they want it mounted cleanly. <\/p>\n\n\n\n

Pretty good installation work, honestly!
Conversely, I don’t think I could install it at home myself. (Seriously.)

Most things come down to
whether you know or don’t know, can or can’t\u2014but without the right equipment and tools, you can’t do anything. (Seriously.) <\/p>\n\n\n\n

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That’s how it’s finished.

The plate is SUS304HL, which doesn’t need surface treatment and should last a long time.
Of course, all the nuts are welded to the base, so you can attach and detach all parts just by turning bolts from the outside.
We don’t want to compromise serviceability even after switching to aftermarket parts. <\/p>\n\n\n\n

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We swapped the tank for the usual black one. <\/p>\n\n\n\n

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After switching to a Shorai battery, there’s a space issue.

You should buy the next size up.
Consider the battery size and capacity (AH) carefully; a larger capacity means the battery won’t drain as easily and the starter and ignition will spin strong! <\/p>\n\n\n\n

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I did it this way. (I kept it simple, nothing too fancy.) <\/p>\n\n\n\n

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We squeeze it into the stock battery case. <\/p>\n\n\n\n

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I think everyone dislikes the GPZ750’s tank mounting method, don’t they?
What do you think?

You’d almost want to shout, “Don’t have the bolt base sticking out from the frame!”
Most bikes have pretty worn thread holes, don’t they? (Seriously.)

Anyway, I wanted to remove it, so I made a boss and a jig to center it.
It looks like we’re removing a broken bolt. <\/p>\n\n\n\n

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There was almost no thread left, so it shifted a bit and got misaligned. ( \uff1b\u2200\uff1b)
*No problem at all, don’t worry!

I want to destroy this and convert it to a threaded version (welded boss) and bolt it down.

It would be better to also modify the tank mounting side, but… thinking about it gets long, so let’s go with version 1 for now.

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I drove the fabricated boss in and tack-welded it at four points. Just in case, I made it so the tack welds can be removed and it comes apart.
After I started welding, I thought maybe I should have made the outer diameter bigger. <\/p>\n\n\n\n

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Now it’s solid! M6 bolt mounting. I keep thinking if there’s an easier way…

Making the box that holds down the tank flap removable would make it even more perfect. <\/p>\n\n\n\n

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We changed the oil to Newtech NC50 and the brake fluid to Golden Cruiser DOT4.
We also moved the breather to an easier-to-draw position with SPG hose. <\/p>\n\n\n\n

After a test ride, it’s complete! <\/p>\n","protected":false},"excerpt":{"rendered":"

The machines that WGP riders rode in their younger days still seem to shine today. From the superbike 1000cc era down to 750, from air-cooled to water-cooled, from half-fairings and bikini fairings to full fairings\u2014they’ve changed so much. Maybe they held big dreams about ordinary bikes that were actually being sold, you know? Anyway, let me start with the fabricated parts.<\/p>\n","protected":false},"author":2,"featured_media":34856,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"pochipp_cv_data":"","swell_btn_cv_data":"","footnotes":""},"categories":[1924],"tags":[273,163,213,122],"class_list":["post-34875","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-everyday-events","tag-air-cooling","tag-gpz","tag-gpz750","tag-vehicle-inspection"],"_links":{"self":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/posts\/34875","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=34875"}],"version-history":[{"count":0,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/posts\/34875\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/media\/34856"}],"wp:attachment":[{"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/media?parent=34875"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/categories?post=34875"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.decoboco.info\/en\/wp-json\/wp\/v2\/tags?post=34875"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}