Doms CB550F1 project

[DomP]

I decided I needed a CB550 in my like after completing (nearly) my XS650B restoration.  I found a UK 1976 cb550f1 on 32k and in relatively good condition with very little apparent rust or corrosion, it was last started in 2017 but still turns over so fingers crossed a service and strip and clean of the carbs, new plugs will get it running.  I've bought a compression tester so I can find out what kind of health the engine is in and will stick my inspection camera down the plug holes to see what it all looks like in there.

So far I have discover a few good and few not so good things.

Good-
The frame must have been painted or powder coated at one point as its far too clean bar a few knocks.  A previous owner has gone over it replacing all engine cover fastenings with stainless cap heads.

Not so good-
The gear lever looks to be from another bike, it's been over clamped in an attempt to gain a grip on the shifter splines which are a little bit chewed up.  All float bowl screws are chewed up and are a mix of length and head type, possibly the worst thing I've encountered so far is the rear wheel.  I'd noticed it was very hard to push around so stripped the rear wheel out, the hub has been dinked on the edges by a hammer or something so it was catching on the drum plate.  When I removed the plate from the hub I found very uneven wear on the shoes and lining which has also cracked in several places, new hub or a replacement lining needed. 

[Oddjob]

Good luck finding a new hub or a second hand hub that isn't cracked. However you can get the hub relined with the brake liner out of a Morris Minor I believe. Search the forum for links to who does that type of work, one in lower Wales IIRC.

Sounds like your going to need a new gear selector shaft, I have a couple spare if you do. Also had a gear lever but I've sold it recently. You can find them second hand but the chromes usually crap.

I also have 3 spare carbs off the 550, 069a carbs are standard on that model. I have 2, 3 and 4 cylinders. Not particularly for sale unless you're really desperate, you can heli-coil those threads but it's a tricky job..

[Trigger]

I decided I needed a CB550 in my like after completing (nearly) my XS650B restoration.  I found a UK 1976 cb550f1 on 32k and in relatively good condition with very little apparent rust or corrosion, it was last started in 2017 but still turns over so fingers crossed a service and strip and clean of the carbs, new plugs will get it running.  I've bought a compression tester so I can find out what kind of health the engine is in and will stick my inspection camera down the plug holes to see what it all looks like in there.

So far I have discover a few good and few not so good things.

Good-
The frame must have been painted or powder coated at one point as its far too clean bar a few knocks.  A previous owner has gone over it replacing all engine cover fastenings with stainless cap heads.

Not so good-
The gear lever looks to be from another bike, it's been over clamped in an attempt to gain a grip on the shifter splines which are a little bit chewed up.  All float bowl screws are chewed up and are a mix of length and head type, possibly the worst thing I've encountered so far is the rear wheel.  I'd noticed it was very hard to push around so stripped the rear wheel out, the hub has been dinked on the edges by a hammer or something so it was catching on the drum plate.  When I removed the plate from the hub I found very uneven wear on the shoes and lining which has also cracked in several places, new hub or a replacement lining needed.

All sounds normal to me for a 45+ year old bike that has had a previous owners tinkering   

[DomP]

Thanks Oddjob, I've had a look and got a few leads to chase up regarding the brake lining, I think the carbs are very much salvageable with an m4? Helicoil.

Yes I think so too Trigger, nothing insurmountable...so far!  Is it you that is able to re-line hub brake linings?

[Oddjob]

Yeah M4 helicoil, you'll find the insert is about 2 threads too long, maybe fit one and see and then trim the others before fitting based on what you find when you test fit the first one.

Ignore the screw sizes listed by Honda for the bowls and the tops, the float bowls are too long, the tops are too short So the top ones strip out because there are too little threads engaging and the bottom strip out because the threads come out of the other side of the casting, then they corrode and when you remove them they strip the thread out of the casting as that corrosion gets pulled through or they damage it so much it strips out when you try and refit the screw. Fit slightly longer screws in the tops and smaller ones in the float bowls or trim the existing ones.

There are stainless steel replacements readily available as are new JIS screws, they won't rust and petrol doesn't bother them. Don't fit socket bolts or allen keyed IMO, they can exert too much force and strip out threads.

[Trigger]

Thanks Oddjob, I've had a look and got a few leads to chase up regarding the brake lining, I think the carbs are very much salvageable with an m4? Helicoil.

Yes I think so too Trigger, nothing insurmountable...so far!  Is it you that is able to re-line hub brake linings?

If you are going to buy a helicoil kit, V-coil are suitable for rolled threads 
And the carbs do not have enough meat on them for a  Time insert 

[Trigger]

Thanks Oddjob, I've had a look and got a few leads to chase up regarding the brake lining, I think the carbs are very much salvageable with an m4? Helicoil.

Yes I think so too Trigger, nothing insurmountable...so far!  Is it you that is able to re-line hub brake linings?

I did hub lining but, have now sold the lathe. Near on imposable to find someone with a big enough lathe to take a full wheel so, a full strip is required.
Not a cheap job, the donor Honda brake drum have shot up in price and a lot of work involved.

[Oddjob]

I've done loads of inserts in carb bodies and none have ever failed 

[Trigger]

On 69a's. It does not have enough alloy for the collar with a time insert 

[DomP]

I'm going to order an m4 helicoil kit off ebay, I've used them a few times before so I'm sure it will work on the carb body.  Just to confirm, those are m4 lower bolts (×16) and m5 upper bolts (×8)

I've found a bit more bodgery today, not only have the carb bodies been rattle canned in black with the bowls off but one has been butchered and had the jet JB Welded (up- see pics) although ive managed to pick it apart and removd the mangled jet.  That same body is missing the flat spring steel jet retaining spring, are they available separately?

[Bryanj]

I have ordered some from 4 into 1 in the us but they come in sets, i saved a bit by ordering via a us mate, if you do order and need one urgently i could lend you one

[DomP]

I have ordered some from 4 into 1 in the us but they come in sets, i saved a bit by ordering via a us mate, if you do order and need one urgently i could lend you one

Thanks Brian!  However I'm wondering if I need a complete new body looking at the jet seating area, what do you think?

[Bryanj]

If the O ring fits tight it will work OK, carb sets and bodies are starting to get scarcer, a complete set of 500 or 550 of a different number will be ok if rejetted but dubious about fitting one odd carb of a different number, i have a few odd bits hanging about and will look if you give me carb number but it wont be quick and cant be sure what i have

[Trigger]

looks like the Emulsion tube is all mushed up. Give the carbs a total strip and assess what you need 

[Trigger]

A set is on ebay but, i would ask the seller to send pictures with the float bowls removed >>> https://www.ebay.co.uk/itm/314768758353?epid=10028018716&hash=item4949ae1651:g:71EAAOSwtHRk2AFv&amdata=enc%3AAQAIAAAA0G%2BoGv80GLmU%2BX91MyCkAlV328khKGpRY7WxBNTHfLk3aexNvW%2Bz6uUiZeSY%2FWVllZk7ndskp1ZwRg1D5gUUlRTcSFS5ZH2zLejxTY6F69%2F8scIUYaJh4TU%2FCwQ%2FKwaIHwMXMg78CBh3LRT14pDC%2F%2Bs9KH7Eni2TiVWPDXPmTAMDomwsOapFyy6DT7FzcgppxH3Ka1exZT7n5sF%2BeWZ5nYpnZq8q6pa2We7K1Wt5QVe3L%2FW02G485LX8pMWKYIIDfD1HSMALb6m8D7Ht6Ncn6go%3D%7Ctkp%3ABk9SR86r2L69Yg