Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: dieffe on May 22, 2015, 08:02:06 PM
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After the engine going in and out three times now I have finally got to the bottom of the latest oil leak and it isn't pretty.
In the past the cam chain has been slopping about something chronic in the tunnel, in fact there is evidence it has probably snapped at some stage. There is a massive groove on both sides of the tunnel resulting in a hole that someone has tried to fix with what looks like Araldite.
Number four piston has a slight chunk out of the top of it, nothing serious, just a nick and number one piston is a new one which suggest a valve to piston get together. The slipper is new as are the roller wheels on the tensioner and also the cam chain looks new. There is also a new can carrier for some reason.
Anyway, if you are of a weak disposition look away now.
A bit of wear me thinks.
(http://img.photobucket.com/albums/v161/dieffe123/Bikes/New%20bikes/Leak2_zpst7vqkeei.jpg)
Yep, definitely wear.
(http://img.photobucket.com/albums/v161/dieffe123/Bikes/New%20bikes/Leak3_zpstsfdafzh.jpg)
Araldite failing in it's repair task.
(http://img.photobucket.com/albums/v161/dieffe123/Bikes/New%20bikes/Leak4_zpsfdaj9kpi.jpg)
Luckily I got hold of another set of barrels so it is quite an easy fix. (he says)
If this doesn't sort out the oil leaks I give up.
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I had a DOHC CB750K years ago (1980 me thinks) that did a similar thing. The oil leak on that strangely showed up by keeping blowing the gear change shaft seals. Ended up selling the bike for a song as I knew nowt about engines back then. Actually sometimes, I'm not too sure I know anything about engines now either. ;D ;D ;D
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I know nowt but I do know that's not right.
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That is something i have never seen on one of these bikes. If it has cut that much away, were has all the alloy gone ?
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Holy Fu*ck. That is pretty shocking....
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Seen one like that back in early 80's bike had done at least 120,000 but had a couple of stripdowns for various reasons, new owner ran it for 9,000 with no adjustments--cam seized in Newcastle-upon-Tyne and it was stripped by a dealer up there then I did a round trip from Gloucester in a day with VOLVO 245 estate and trailer to fetch the remains back, rebuilt with new cam chain and all the rest used went on with original pistons and rings in SH cylinders for many more years
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Not a pretty sight, but glad you have got to the bottom of it
Cheers
Dennis
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That is something i have never seen on one of these bikes. If it has cut that much away, were has all the alloy gone ?
My thoughts exactly, where did all the ally go?
There is no sign of any remnants anywhere and it appears that the whole thing has been stripped and rebuilt so I guess it has all been cleared out.
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I got the replacement barrels on today, just have to wait now for the headset to arrive so I can finish it off and get it all back together again.
Why is it always a bank holiday when you are in a hurry for something!!!
Patience is a virtue I don't really have much of. ::)
(http://img.photobucket.com/albums/v161/dieffe123/Bikes/New%20bikes/Barrels1_zps3ic3odkq.jpg)
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Well it doesn't leak any more.
HOOORRAAHH!!!!!!
Saying that I haven't been any great distance yet, just round the block, but last time it leaked almost straight away and so far nothing. ;D
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Great news, pleased for you.
Cheers
Dennis
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Normaly if they are going to leak it happens quickly so well done for fixing the PO's keeerap
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I went down to the local bike pub (the Tap) today, all of a 4 mile round trip, and not a drop of oil was to be seen. It went sweet as a nut but I wish there was something I could do with the front brake, any recommendations for better pads or any other suggestions.
Other than the brakes it was a joy to ride not having to worry about leaks.
I got some positive comments too which is always nice. :)
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What are you compairing the front brake to? if its a modern bike forget it you will never get it that good, if its an old brit --what are you complaining about it stops better doesn't it!!
In all seriousness a well fettled brake with decent pads should slow you down OK but not be able to squeel the tyre
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What are you compairing the front brake to? if its a modern bike forget it you will never get it that good, if its an old brit --what are you complaining about it stops better doesn't it!!
In all seriousness a well fettled brake with decent pads should slow you down OK but not be able to squeel the tyre
I recently rode a friends newly restored Kawasaki H2, with factory twin disc conversion, at the first corner I nearly binned it :o, it felt as though it speeded up when I hit the brakes!, brake technology has moved on so much since the 70's, if I'd applied the same amount of brake pressure on my XJR I would have locked the front wheel, I was told that the grade of stainless that the japenese used on the 70's discs was not ideal for braking, low frictional qualities, so regardless of how efficient the pads or calliper are the brake can never perform like modern set ups, not sure if that's correct but Bryan is right the brakes are what they are, all you can do is ensure that they are bled properly, the pivot arm is free and set up so that you have the pads with the correct clearance to the disc,after that all you can do is ride as you did in the 70's, i.e. slower :).
interesting point re compounds though, shame nobody makes a HH compound pad, it would help a bit.
P.S. you could get a cast iron disc fitted, some of the classic racers do that but then it wouldn't look right and you'd forever be cleaning rust from the disc.
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You just have to remember to brake way ahead when you want to stop, I have not been polluted by modern bike brakes so I am only used to my trusty old single disc, maybe I'll see you down the Tap sometime as well, I'm only in Great Sutton.
Cheers
Dennis
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Rough the disk up with some scratch in a cross hatch pattern I use the pads from DSS rough these up as well make sure there adjusted well and the pivot pin is free and well greased.I haven't had to many scary moments rain or shine.
ACF50 grease is my new favourite product for the backs of brake pads and greasing the pivot as it does not go hard overtime like conventional grease and they have stayed squeak free ;)
Mick
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Your right about the HH pads. My F2 has HH pads, braided hoses, new master, and refurb calipers. And this is the honest truth, it stops as well as my CB1300. I was very impressed. They should make HH pads for all models as a safety measure.
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Your right about the HH pads. My F2 has HH pads, braided hoses, new master, and refurb calipers. And this is the honest truth, it stops as well as my CB1300. I was very impressed. They should make HH pads for all models as a safety measure.
Yes Roy I fitted them to my XJR and the difference it made is amazing, I guess they wear the discs much more though so I've started using my back brake a lot more, it's amazing how little I need to use the front brakes now, plus it's safer at junctions in case there's any unseen gravel or diesel, front discs for the XJR are £300 so I'll preserve them as much as possible!😀
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I had Carbone Lorraine pads in both of my XJRs and the brakes were superb. I wonder if they list them for the Honda, (yeah, right).
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No I don't think they do. Spent a good hour yesterday searching for HH pads for my 350F without any luck. Would be pleased to hear if anybody has found a source for these. The only HH pads I can find for any SOHC is the Honda 750F2 same as mine. I think were out of luck?
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Anyone know what these are like?
V-Pads (http://www.ebay.co.uk/itm/EBC-V-Pads-Semi-Sintered-Front-Brake-Pads-1977-1978-Honda-CB750K-FA13V-/181146999685)