Is this crank usable?

[Sye]

I have just opened up the bag with the crank parts in and don't know if the webs/counterweights are usable. I've seen some on here with pitting but don't know if these are just too bad?

Any advice welcome.

[nickb st]

the only way to tell is to take the crank to the rebuilder
I use pjme in the midlands of England.....

http://www.pjme.co.uk/acatalog/Crank_Shaft_Rebuilding.html

[Gerrit]

The crucial point is whether there is any corrosion in the crankpin bores and on the male/female pressfit of the inner webs. The corrosion on  the flywheels themselves can easily be removed with 800 wet-and dry, use plenty of oil. Pitting in these surfaces isn't critical, but most definitely IS critical in the press fits. These have to be checked ie measured to see whether they are still within tolerance.

[Sye]

the only way to tell is to take the crank to the rebuilder
I use pjme in the midlands of England.....

http://www.pjme.co.uk/acatalog/Crank_Shaft_Rebuilding.html

Thanks for the link Nick. I called them and they said that they can't do twins and had never done a Bridgestone.

[slawsonb]

I would also dip soak these in a Chelating rust remover. It will disolve the iron oxide, but leave the underlying steel. Gently polish with a brass brush before going to the sandpaper. (it may take a couple of cycles of dipping and brushing to get to the virgin material.) This will give you a good idea of the raw state of the parts and should not affect the dimensionality except where the iron oxide has been removed, but you need to do that anyway.
...bert

[ziggy stardust]

Try this link Sye. http://www.stanstephens.com/2stroke.htm

Z

[Colin]

Yup Stan Stephens is the man he will rebuild anything 2 stroke, if you want the motor tuned too he is most definitely the main man in the UK

[Sye]

Try this link Sye. http://www.stanstephens.com/2stroke.htm

Z

Thanks Ziggy, called him and he has stopped doing work other than engine builds on YPVS and RG bikes. The more I think about this, the more I'm inclined to give this new restoration a miss.

[Gerrit]

There are probably others in the UK that can rebuild twin or multi cranks, I can hardly accept that Stan Stephens would be the only one capable of doing so.
When reassembling,the correct order of the flywheels is: LH outer, female inner, male inner, RH outer according to a drawing in the GTR service manual.

[ziggy stardust]

There are other businesses advertising to do crank work, I just pulled this one at random and it's close to you as well.

http://www.kpmotosolutions.com/crankshaftrebuilds.htm

I was surprised Stan Stephens wouldn't do it after all the publicity he's had recently in various magazines claiming that he's the man?


Z

[Sye]

There are other businesses advertising to do crank work, I just pulled this one at random and it's close to you as well.

http://www.kpmotosolutions.com/crankshaftrebuilds.htm

I was surprised Stan Stephens wouldn't do it after all the publicity he's had recently in various magazines claiming that he's the man?


Z

Thanks again Ziggy. I've phoned him and several others around the country but they all say that it needs a jig (that they dont have). Something to do with the centre pin being plain and not splined?

I will keep my eye out for the two outer webs I need for a while and if I have no luck will kick it into touch and sell the rest of the bike parts on.

Cheers.

[Gerrit]

What a load of nonsense! Yamaha cranks have splines, but Kawasaki cranks don't- they have dowel pins. Not sure about the way Suzuki cranks are built up, but as far as I know they don't have splines either. It sounds more like "I dont know anything about Bridgestone cranks and I don't want to know."
I don't know whether Bill Smith in Chester are still in business, but they were the Bridgestone importers for the UK if I'm not mistaken and may be able to help if they are still around. They may no longer have parts but they may have a jig- why throw that away?

[BRT-GTR]

Sye,
               Have you tried this one .

      http://firefoxracing.co.uk/engine-servicing/

   Bill Smiths are still in business in Chester, they had a GTR crank rebuilt for me back in 1970, but I think they farmed it out to Dugdales at Alvanley, if my memory serves me correctly. Dugdales are long gone unfortunately.
    Brian.

[Sye]

Sye,
               Have you tried this one .

      http://firefoxracing.co.uk/engine-servicing/

   Bill Smiths are still in business in Chester, they had a GTR crank rebuilt for me back in 1970, but I think they farmed it out to Dugdales at Alvanley, if my memory serves me correctly. Dugdales are long gone unfortunately.
    Brian.

Thanks Brian, Bill Smiths is a no go. The only guy who could do the job there is a guy called Geoff Wilding who has long since hung up his spanners.

Called Firefox Racing and spoke to a guy called Andy. Result! I will be sending everything to him and he is sure it can be sorted so watch this space.

Thanks again.

[BRT-GTR]

Hi Sye,
            That's good to know. I've been bookmarking crank rebuilders myself in case I need their services. I think firefox was the only one left on my list after eliminating the refusals that you've received. Let me know how you go on and whether they are happy to reuse your flywheels.
    You seem to be getting hooked on Bridgestones, they are an addiction, there's no cure for it..............apart from getting more !! 
 Good luck, Brian

[steve]

Sye,

SEP of Kegworth rebuilt the crank from my GTO and did an excellent job. Their no is 01509 673295. They did this just before Ray and Richard had organised the pattern conrod kits and as mine had been damaged, SEP sourced replacements from a different bike and did the necessary machining work to suit the piston pin. I've used them on and off for many years and they're good guys.

Steve

[farmerdl]

Either Don Vesco or Tony Murphy (possibly both) drilled and doweled GTR cranks back in the late 60s -  early 70s when they raced these bikes.  I would believe any good shop rebuilding cranks would be able to drill for a dowel before the center sections are pressed apart.

[Gerrit]

Tony Murphy's article on his GTR racer recommends a dowel pin and includes a pic which shows the dowel and the flywheels. Tony used a 3/16" diameter dowel which translates to about 4.76 mm. As a comparison, Kawasaki triple cranks use 5 mm diameter dowel pins, 12 mm long (Kawasaki part No. 610A0512).

[Colin]

I'm shocked to hear Stan Stephens no longer does anything except RG's and RD's
hmm what's the world coming too, never mind you have at least 2 options now.

[nickb st]

stan part retired in 2000 (closed his shop at Brands) - he must be 75 now !

the money is hot for 4cyl 2 strokes - must be easy money for him,
and fill all the time he wants to work in his shed in his back garden !

also engineers like complete cranks so the know how it should fit together
it might take more time trial and error to get right......