1990 FZ750 Fork Rebuild

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1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

I've got a fork seal that keeps leaking despite being replaced twice on the 31 year old FZ, had a feel round the fork and there's a pit on the rear of the fork that will be damaging the seal, there's also a chance that the fork might be lightly bent as I've spotted (after 4 years of owning it) that the right hand side of the fairing bracket is a little bent.

So today I've ordered a Tarozzi fork leg, a fork bush, a fork seal and a pair of YSS progressive fork springs.
Problems I envisage - getting the bolt that holds the damper rod in undone after it not having been disturbed for 31 years, apart from that I can't see there being too many problems, hopefully get it done this weekend if all the parts arrive and my small bald assistant is available.
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Re: 1990 FZ750 Fork Rebuild

Post by Skub »

You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
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Re: 1990 FZ750 Fork Rebuild

Post by KungFooBob »

Don't bother with pics, you always post too many.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

KungFooBob wrote: Mon Jun 14, 2021 4:26 pm Don't bother with pics, you always post too many.
Bitch, it's because my phone takes pictures that are too big to put directly into posts.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Skub wrote: Mon Jun 14, 2021 4:16 pm You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
Apparently a broom handle will do it, but I will investigate further.
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Re: 1990 FZ750 Fork Rebuild

Post by KungFooBob »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:36 pm
Skub wrote: Mon Jun 14, 2021 4:16 pm You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
Apparently a broom handle will do it, but I will investigate further.
I used a broom handle on my R6 forks and it worked.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

KungFooBob wrote: Mon Jun 14, 2021 4:41 pm
Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:36 pm
Skub wrote: Mon Jun 14, 2021 4:16 pm You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
Apparently a broom handle will do it, but I will investigate further.
I used a broom handle on my R6 forks and it worked.
I've never had to hold the damper rod, just used an air impact driver on the bottom bolt with the fork fully assembled, but I've got a feeling this one is going to be a pig, I'm also thinking the bush will be a git to get out.
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Re: 1990 FZ750 Fork Rebuild

Post by Skub »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:36 pm
Skub wrote: Mon Jun 14, 2021 4:16 pm You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
Apparently a broom handle will do it, but I will investigate further.
I used a sharpened brush shaft for an LC years ago. :lol:
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Re: 1990 FZ750 Fork Rebuild

Post by Skub »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:45 pm
I've never had to hold the damper rod, just used an air impact driver on the bottom bolt with the fork fully assembled, but I've got a feeling this one is going to be a pig, I'm also thinking the bush will be a git to get out.
I don't know if it's a Yamaha trait,but it was very easy to bugger the fork bushes when replacing seals and added considerably to the cost.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Skub wrote: Mon Jun 14, 2021 4:48 pm
Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:45 pm
I've never had to hold the damper rod, just used an air impact driver on the bottom bolt with the fork fully assembled, but I've got a feeling this one is going to be a pig, I'm also thinking the bush will be a git to get out.
I don't know if it's a Yamaha trait,but it was very easy to bugger the fork bushes when replacing seals and added considerably to the cost.
There should be a washer between the seal and the bush, I may have damaged that when I replaced the seal previously, hope not because a replacement will have to come from cmsnl in Holland and they charge a fortune for postage.

The new bush was £9, I think the existing one has worn out which is why the seal doesn't last long, I've never done a fork bush before so it could be interesting, if it gets too difficult I'll be phoning Darren at MCT for assistance.

Just to add to the fun, the fork sliders on my FZ were only used for the last two years of FZ production and are quite rare in Britain, but all FZs have the same fork bushes, seals and damper rods.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Ordered the washer, another £8.91, from eBay, seller is fowlersparts, weirdly Fowlers say they're out of stock on their website, but have 6 on eBay
Hopefully I won't get a message saying they haven't got them.
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Re: 1990 FZ750 Fork Rebuild

Post by Bigjawa »

Skub wrote: Mon Jun 14, 2021 4:46 pm
Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:36 pm
Skub wrote: Mon Jun 14, 2021 4:16 pm You'll also need a tool to hold the inside head of the damper rod while you loosen the retaining screw. I used to hate how they were all different.
Apparently a broom handle will do it, but I will investigate further.
I used a sharpened brush shaft for an LC years ago. :lol:
Yup, same here, had to buy my ma a new brush after.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 5:17 pm Ordered the washer, another £8.91, from eBay, seller is fowlersparts, weirdly Fowlers say they're out of stock on their website, but have 6 on eBay
Hopefully I won't get a message saying they haven't got them.
Got a message today - Fowlers haven't got them, fortunately there was another one on eBay, so I bought that, £15 instead of £8.91 though, but I suppose if you need one you have to pay more to get one quickly, but in the grand scheme of things £6.09 is nothing.
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Re: 1990 FZ750 Fork Rebuild

Post by MingtheMerciless »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:34 pm
KungFooBob wrote: Mon Jun 14, 2021 4:26 pm Don't bother with pics, you always post too many.
Bitch, it's because my phone takes pictures that are too big to put directly into posts.
Then just email yourself the pictures and reduce the size that way.
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Re: 1990 FZ750 Fork Rebuild

Post by mangocrazy »

Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:45 pm
KungFooBob wrote: Mon Jun 14, 2021 4:41 pm
Le_Fromage_Grande wrote: Mon Jun 14, 2021 4:36 pm

Apparently a broom handle will do it, but I will investigate further.
I used a broom handle on my R6 forks and it worked.
I've never had to hold the damper rod, just used an air impact driver on the bottom bolt with the fork fully assembled, but I've got a feeling this one is going to be a pig, I'm also thinking the bush will be a git to get out.
Ever since I've owned an (electric) windy gun I've never had a problem with bottom fork bolts. They just fly out. I have had problems sourcing the correct sized replacement crush washer though.
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Re: 1990 FZ750 Fork Rebuild

Post by BBB »

Also struggled to find crush washers for various fork bottoms. If you have one of the correct internal diameter I used to put them on a bolt stick that in the chuck of an electric drill and hold that against a file. Just keep them spinning until they're the right external diameter.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Ordered a crush washer from Fowlers, £3.88 including postage, hopefully that's everything I'll need.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

Asked my mate if he's got a rattle gun, if not I'll be making a trip to Machine Mart - new tools :D
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Re: 1990 FZ750 Fork Rebuild

Post by mangocrazy »

Le_Fromage_Grande wrote: Wed Jun 16, 2021 11:11 am Asked my mate if he's got a rattle gun, if not I'll be making a trip to Machine Mart - new tools :D
I picked up a mains rattle gun from Lidl a few months back for about £30 and it's absolutely bloody brilliant. It's done bottom fork bolts, castle nuts on car gearbox shafts, anything you put in front of it, it just whizzes off. It's lighter, better balanced, more compact and more powerful than the mains electric rattle gun I bought from Machine Mart some years ago (which in itself is a good bit of kit).

I'd like a battery electric rattle gun, but I just know that with my usage profile the batteries would expire well before the gun did.
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Re: 1990 FZ750 Fork Rebuild

Post by Le_Fromage_Grande »

You can get 12V ones that work off car batteries, £35 from Machine Mart
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