i need a tool to split the crank on my 1980 honda 200 benly motor cycle can any help
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i need a tool to split the crank on my 1980 honda 200 benly motor cycle can any help
I'm going to send out this question to our motorcycle guys, and you should be able to get some good responses.
If I'm not mis-steakin', you'll need a press and some V-blocks to rebuild a pressed together crankshaft.
I have never seen a "tool" to do it any other way.
1st sorry for my poor and mistakefull English,but I'm a self teaching people.Quote:
Originally Posted by oldie
Well,I'll try to tell you about crankshaft splitting,but some things need to be clear before. This shaft is a composite one,so your work is both side needed.
You can use a normal pin bench press to push out the connecting pin ( which is one only for all crankshaft) from the each side,living the pin and all the rest were it is.
Different if you need to disassemble totally the item.
In any case are enough two a 10 or 12 mm rectangular plates to hold the part when you press the pin out.
The best is warm by hot air the pin area during operation.
Much more difficult is after recomposition,make the perfect centering of alla the crankshaft,which is a very handly experience work.
That the reason why I suggest You to ask to a workshop were they do this work,expecially because a very little difference....make the difference.
But in any casa write me about the problem and step by step I will try to help you.
Try to take a look about how the item is composed here were a free spare parts catalog is.
https://www.classiccycles.org/templa...0/kv_11999.jpg
Giorgio
Is a process not so easy to explane in few words.
I use a MotionPro case splitter
Because I so lots of different engines I chose this brand and type. I would NOT try to split the case without this tool. Heatng the casing where the bearings are press fit helps split and install the case
Hi Oldie, I'm a bit confused because of the title saying Crankcase and the text saying Crank, (which I take as Crankshaft). Which is it? It appears that others below are too. I don't know the Benly version but looks similar to a CB200. I've worked all kinds of bikes and on Honda's all the way back to the Trail 50 up into CBF750's to the early eighties Honda's.Quote:
Originally Posted by oldie
If it is the Crankcase you will either need to purchase a "Splitter" or build one. If it's the crankshaft most a pressed together and pinned. You will need heat (oven) for that and get the pin out first if possible...but can't understand why you might need to separate the Crankshaft??
Tony Foale, One of the new people here would be quite able to help I'm sure with his time in the UK and all the bike stuff he does.
~PJ
Sorry,I've replayed in a wrog argument, 'cose I was thinking about crankshaft disassembling.Quote:
Originally Posted by oldie
Asking sorry, I suggest a plate 8 or 10 mm thick, large enough as a crankcase cover in the part were the crankshaft is.
Then put the engine side cover on the plate and mark some of the retention screw holes. Then you need to obtain the hole were you will put the treated bar as a extractor.
Nothing easy. If you take a look the crankshaft have a little cone hole were alternator rotor is fixed. Is the hole used to center the crankshaft.
Put a sphere there ( in the hole) and then screwing the plate by the screw on the crankchase. when plate will be in contact with the sphere, a little bang by hammer in the touch area will live a sign enough to understand were make the hole.
Then two chances: 1st thread the hole and use a big enough bolt as extractor pulling plate on the crankshaft, or
2nd make a clean hole and use a bolt and nut ( nut under the plate) with the same effect.
Mount the plate by screws on crankcase and work by the central screw as a extractor.
If the plate is big enough, you can obtain the other side case hole with the same process.
To use the same center hole ( were you work with the big screw or bolt) you will put the central bolt in right center position and then by some hallen screws posed on treaded case hole,obtain hole marks. It is necessary only pose some spheres on hallen cave. By this way you can adjust at the same time the plane in case of difference in high.
In all the ways i suggest to hold in position spheres by some hard grease.
Misundertanding for me too. My first answer is about crankshaft.
My second to crankchase.
Crankcase really easy
Crankshaft a "little bit" more difficult.
hi sorry for my error It is the Crankcase that i am trying to split.the bike is a 1980 honda 200t benley that had been laid for at least 20 years got it running only to get oil leak .need to replace seals .i purchased a crankcase splitter on amazon that snapped on use a better quality one will cost about 150 uk pounds .if i dont get it done while its fresh in my mind it will be a lot harder,any help will be great. thanks
Hi, Check this link, but you'll see that it needs a 20 tonne press so maybe take it to your local auto shop to get it parted.Quote:
Originally Posted by oldie
A really hefty hydraulic puller might help instead (I have a 30 yr old Sykes Pickavant 20 ton puller)
Mark across the webs before you start to make sure that they align when you rebuild it.
They are held purely by interference fit.
1971 CB175 (K5) - Rebuilding Miss Daisy - Page 8
Start reading at post #73
In the past (not on Hondas, I have just bought my first Honda, a 1987 VF700C Super Magna) I have sometimes had success using hardwood wedges or (bit of a long job) fit nuts and bolts between the webs and unscrew the nuts to put pressure on the web (need to maybe pack out the bolts as the nuts are only going to give you 5mm movement but that would be enough.)
If you do it yourself, take your time and make sure that when it parts (it will go with a bang) it doesn't fall on your foot (or even worse - the floor!)
Best of luck
Tom
Splitting crank is actually a lot more difficult on that motor as it has a steel plate on left side to direct oil from main bearing to big end. Earlier bikes (CB350 et.al.) had a 'lip' on flywheel so caught oil centrifuged out of main bearings to lubricate big ends. (they are not pressure fed) The 125 version of the motor had left side big end failures if oil was not checked regularly and kept between middle and top mark of dipstick. (125 also has a 12,500rpm redline) I have changed left big end bearings on 125 but it isn't easy. Freezing the crank and applying local heat to outside of flywheel may enable the plate to be removed without damage but it's a difficult crank to fix.
If you want to split cases, just make a tool from some flat plate and a few nuts and bolts. If it isn't coming apart relatively easily you either still have some bolts in place or your using tool wrong.
Oldie,
Please see attached. This outlines the method of separating and rebuilding a pressed up crank.
Attachment 15623Attachment 15624Attachment 15625Attachment 15626Attachment 15627Attachment 15628Attachment 15629Attachment 15630Attachment 15631Attachment 15632
I was wondering when the Alfa Bearings instructions would appear. Kudos for taking the time to upload it.
I've used the instructions in one form since around 1979 or so. ( I taught pressed up crank building/truing at MMI for several years as a 'machine shop' instructor) It's easier to make a 'press plate' to separate the halves
As I previously mentioned, Honda use what is referred to as a 'tin can' crank on 125~200 twins so crank pins are not seen until covers are removed (they used similar concept on CR125/250) The instructions work when you have access to crank pins but there are no instructions on removing the covers without damaging/destroying them. It's been such a long time since I did 125 twin crank I can't remember how I got plate off left side without damaging it (it IS possible though)
