Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: mickwinf on April 06, 2014, 08:07:47 PM
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Well this is what happens when you have some spare time and a Honda engine, I was just going to clean and paint but decided to strip it down to check the condition as it is an unknown. The hardest thing was getting the barrels off, they were stuck, the rest of the strip down went very well. It is in pretty good condition, crank is good and gears seem ok except the centre selector is badly worn, anyone have a spare? Will replace all gaskets and seals, also primary and camchains. will keep me busy!
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Nice one Mick you know you love doing it and in the END when finished you know its GOOOD.
Cheers
Bitsa
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Hmm... that bag of extra rapid cement nearby just waiting for the 'right moment'!
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That centre selector is very hard to find in good order now, its the same as a 350 twin i think so the US ebay is probably your best bet mate
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ha Lobo I think the moment has passed for the cement, gone hard already! Bryan will try ebay USA.
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How different are 500 and 550 selectors, I have a few engines that came as boxes of cogs and they are all a mix of 500 and 550 bits, been 10 years since I built anything up out of it, I seem to recall most bits were possible to interchange, but some annoying differences, like having to tear the whole thing appart to swap the actual gear shaft to fit the cluch, took many long hours of trial and error to make a viable engine - gearbox was good, shame the crank seized (think it was petrol washing the oil out due to bad rings on piston and sticky float but given that I was utterly clueless and working in a caravan between shifts, maybe some dirt got in there.
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Hi Matt, I have checked my parts books and the 550 is different part number, not sure how to tell difference without comparing side by side, if you do have one I would buy it!
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I'd keep looking over in Us of A to be honest Mick, I might well have one, but my workshop is a right royal tip and it will take me an age to find one, and identify it as 500 rather than 550. Could take an age. I wonder could a worn one be built up with weld then machine it back? I would need to be really accurate and re case hardend. I think my 500 may need the same part - does it select 1st gear by any chance? Does seem jumping out of 1st was a common 500/4 issue thinking on it.
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Mick, you can't go by part numbers. I know that CB500T forks are identical to CB500 and CB550 but, all have different part numbers. As you say the only was is to match these side by side.
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If 500 and 550 forks were the same then I have plenty, but I don't think they are - been a decade since I did a mix and match rebuild though. I have a shed to erect, a big tree to fell in a tricky spot that has to come down first and then I'll be able to clear enough space to work on an engine. Not gonna be fast. Until then no knowing where any given for in the spares boxes came from.
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I don't know if there was a problem with selection as I bought the bike in bits, don't want to put it back together if it will cause problems. Will keep looking on ebay
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500 forks fit on the selector drum, 550 pivot on a seperate shaft so are totaly different.
They were originaly hard chrome plated and ground to a specific thickness so could probably be repaired with stellite weld and a good machinist/grinder but that would be dearer than a used one from the states.
See list below from motogrid as to what bikes to look for:
CB350 A MOTORCYCLE, JPN, VIN# CB350-1000001
CB350G A MOTORCYCLE, JPN, VIN# CB350-5000001
CB350K2 A MOTORCYCLE, JPN, VIN# CB350-2000001
CB350K3 A MOTORCYCLE, JPN, VIN# CB350-3000001
CB350K4 A MOTORCYCLE, JPN, VIN# CB350-4000001
CB500 A MOTORCYCLE, JPN, VIN# CB500-1000001
CB500K1 A MOTORCYCLE, JPN, VIN# CB500-2000001
CB500K2 A MOTORCYCLE, JPN, VIN# CB500-2100001
CL350 A MOTORCYCLE, JPN, VIN# CL350-1000001
CL350K2 A MOTORCYCLE, JPN, VIN# CL350-2000001
CL350K3 A MOTORCYCLE, JPN, VIN# CL350-3000001
CL350K4 A MOTORCYCLE, JPN, VIN# CL350-4000001
CL350K5 A MOTORCYCLE, JPN, VIN# CL350-5000001
SL350 A MOTORCYCLE, JPN, VIN# SL350-1000001
Note that the 250 K was not seen in the states so chances are that that is the same as well
USA ebay item
http://www.ebay.com/itm/1971-1972-1973-Honda-CL350-CB350-CB-CL-SL-350-Transmission-Shifter-Shift-Forks-/281155899624?pt=Motorcycles_Parts_Accessories&hash=item41763290e8&vxp=mtr
set of 3 but other two don't fit the 500, not worth asking for just the one you want as chances are the wrong one will be sent
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cheers Bryan
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Bryan, I can concur, the CB250K, CB350K and CB500K all same part. If anyone is really stuck I can help but it is a shame to break a good gearbox just for one part. I'll have a look and see what I have in the workshop.
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thanks Florence if you have a spare one I am interested but as you say don't split a good box. I will post a picture of the old one to get some expert opinions.
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ok
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As a wild card option Bemw in Derby do all sorts of clever metalwork and engineering, or did when I last visited. Hopefully you'll find a source for the good one you need but at some point and probably soon it may prove to be the case that reclaiming a worn one is going to be the way to go. Posting a picture might well help identify the required part - slim though it may be, there is a chance I have a spare that is getable at - I have 3 plastic crates of 500 and 550 bits in addition to the engines and whilst I've no room or time to strip an engine, rummaging through a box might prove do able.
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I have located one from the USA, will post a picture of old one when I have time to take it out of the crankcase.
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Get a small round magnet on a stick (mine is Snap -On) to get the pins out which run in the drum grooves and also note which way out the "R" clips go as many an unhappy hour has been spent try to remember and find the one that pinged across the workshop!!
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cheers Bryan I will be careful
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this is the old selector fork, you can see it has worn badly
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another pic
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Ken the tip on one side has worn a groove about 1mm deep, you can just see it on the pic, it has the number 51 stamped in it.
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I had a look at the sliding dog and it looked good, in fact the whole bottom end looked good apart from this one item, so will put it back together with new primary and cam chain and hope for the best!
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For some reason it's always that selector that shows wear and nearly always the same pattern.
If i sat and thought about it perhaps i could think of a good reason but can't really get steamed up about it.
over the years I have seen most of the gears damaged in some way but not one more than any other, as long as you strip and repair before they jump out regularly i think just the selector will cure any problem
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well I received my selectors from the US, I actually ordered 350 k items as the one I wanted is the same. It turned out to be in good condition, although another one in the set looked quite worn, so was lucky. I have now rebuilt the bottom end with new chains etc, and tonight have refitted to the frame while still partly stripped as I cant lift a full engine on my own. Glad to be making progress!
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Nice mick. Is the engine paint or vapor blast. Spotted a whole gear box on ebay uk last night.
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Trig I had to clean the engine the old fashioned way with gunk and toothbrush then wire brush and dremmel, then sprayed with silver smoothrite. Head and barrels will be hi temp silver.
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Now ready to install oil pump, and I have read somewhere it should be primed before use, how is this done?
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Never had to do one yet but you can fill them with vaseline
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recently had to replace clutch plates,
what gasket sealant ,and gasket do you all use??
I used Hylomar Blue ,
your comments ??
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Nothing wrong with Hylomar, apart from being Blue. I use RVT marine silicone and Vesrah gaskets. NP gaskets are also a good option.
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I used hylomar on the crankcases but with a gasket I use a smear of grease.
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Well some progress today, got the barrels and pistons installed, was a bit fiddly as I did it on my own without a piston ring clamp. also started on the head which is a second hand one so needs the valves grinding and stem oil seals renewing. Problem is I don't have a proper spring compressor so I am using a home made tool with a woodworking clamp. it works great to remove but I am having difficulty replacing the collets as there is so little room to play with. I have tried tweezers, magnetic screwdriver and grease but took me ages to get one valve done, then realised I had not installed the stem seal!! managed to get one done after lots of swearing, but another 7 to do, any tips??
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You need a valve spring compressor. Yes, a bit of grease will hold the collet. make sure you hit the valve once in, to make sure the collet is seated right.
Also make sure that the two washers are over the valve guildes. Sometimes they will fall out or the inner one will glue itself to the bottom of the spring.
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luckily I had some spare valve parts as some went flying across the garage never to be seen again, the washers are still in place. I can compress the spring ok but cant get the collets in place
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I am having the exact,same problem with my 400F engine. >:( I am using a valve spring compressor,and can get one collett in,but not the other half!! :( :(
This is doing my head in. >:( >:(
cheers, Kenny.
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Mick, you need to compress a little more down the stem. I have my compressor set so it is 5mm past the collets, place them in with a little grease and the release the compressor so it comes up fast. If the valve cap is not coming up even then it will always knock the collets out.
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Kenny it is just a bit of skill. You also need to compress a little more. If the compressor is set right it is very easy.
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Cheers, trigger.
Will keep trying. :) Kenny.
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Done!! :)
If anything, I was compressing spring to much. But doesn't matter now,as they are in and seated with the help of a rubber mallet. :) :)
Kenny.
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Well done Kenny. See if you try it all happens in the end.
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Before putting the head back on check that all the valves are seated. By testing them with fuel down the ports. Do not know if you have re-cut the seats and lapped the valves in???
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Nice one Oddjob. :) :) :) :) :) :)
Lapped valves etc. yesterday. All is o.k. :) :)
Kenny.
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More progress, got the valves installed with my new spring compressor (ebay £20) fitted the head with genuine Honda gasket. Just the rocker top to install then engine is complete ready for carbs and exhaust. Cant wait for the first start up!
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exhaust and carbs fitted, a bit of electrics to do before first start up. Problem is I have been on ebay again and bought a 550!!
http://http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=181470532096
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It lives!!!! yes got it going today, sounds good but valves will need doing again and carb sync, bottom end sounds quiet with hardly any clutch rattle or chain noise. Good day!