blutaco Posted October 16, 2015 Report Share Posted October 16, 2015 I've just acquired a 1966 Model 10 for restoration that has had its bottom frame loop sliced off and replaced with a skid plate. I'd really prefer to restore her to a good old fashioned bottom loop. The 4 speed engine of course has its third engine mount below the gearbox so at the moment all these 18 Bultaco HP's are suspended by 2 bolts only. Is a replacement frame (hen's teeth?) my only option here? 1 Quote Link to comment Share on other sites More sharing options...
woody Posted October 16, 2015 Report Share Posted October 16, 2015 Sounds like a major exercise to restore the frame to original but a decent fabricator could do it with pictures. The chances of finding another model 10 frame are next to nil Or you could get a better bash plate made and bolt a bracket to that for the bottom mount, as they did with the Beamish Suzuki Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 16, 2015 Author Report Share Posted October 16, 2015 You are confirming my fears, Woody! The poor thing has been butchered and I would like to give her my best shot. 'Parting out' is a crime so that's not an option. I acquired a M49 frame at the same time as it was suggested that it could be a dobor for the bottom rail but I could not do that to a good frame! This is turning into Challenge Aneka! Quote Link to comment Share on other sites More sharing options...
twinnshock Posted October 16, 2015 Report Share Posted October 16, 2015 Where are you located. I am located in North Essex (UK) and have a Model 10 frame you could come and take measurements from. An actual model 10 frame is hens teeth but the lower loop from several other early models fitted with the 4 speed engine are similar if not identical so could easily be grafted in place by a competent welder. The first matador, model 16 frame is basically the same frame with additional webs.(this model was developed from the model 10) If you could get one of these frames they can easily be modified to model 10 standard. More than one model 10 has been rebuilt with a model 16 frame. I was told this by Dave Renham but I suspect actual owners will not be so forthcoming. I have a model 16 frame (not for sale) and I have measured it side by side with the model 10 and can confirm the main loop has the same geometry including head stock angle.If you are in the UK and able to visit you would be welcome to see the two frames side by side. In other words this is probably not as difficult as you might think. Please do it. Stuart 1 Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 16, 2015 Author Report Share Posted October 16, 2015 Ok. Sounds encouraging, TS. I'm in Scotland and not particularly mobile but photos would help. Even if I left the crankcases in situ, that would form some sort of jig for a frame builder to work to. When I was a young lad this is the sort of problem I had wise older heads to turn to. Thank God for the Internet! Quote Link to comment Share on other sites More sharing options...
twinnshock Posted October 17, 2015 Report Share Posted October 17, 2015 Blutaco . I will sort out some photographs and send them to you. It will take me probably about a week to find the time to get the frames out of the shed and take the photo's. Could you PM me an email address to send theses to. I have to be honest with you my M10 frame is very rusty in this lower loop area and I am a bit concerned about it strength. This is why I have the model 16 frame as I intend doing a similar task as you propose. It is also why I have measured the two frames side by side. I started on my Model 10 project about 3 years ago but it has been side lined as I am working on restoring a BSA car, Hopefully will be back onto it next year. The model 49 frame will provide donor parts but I think they changed the size between the 4 speed and 5 speed engines so will need more work than a model 16 frame. When I take the photographs I will try a set of model 80 crank cases in to confirm my suspicions. Stuart/Twinnshock. 1 Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 18, 2015 Author Report Share Posted October 18, 2015 Thank you for this very encouraging reply. I have messaged you my email address. Any help is appreciated greatly. John Quote Link to comment Share on other sites More sharing options...
jlpar Posted October 26, 2015 Report Share Posted October 26, 2015 Blutaco, I also have a Model 10. There are pictures of the frame on my Old Bultaco post if they are any use to you. If you want I can take measurements for you of the areas you require. Good luck with it. Larry 2. 1 Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 26, 2015 Author Report Share Posted October 26, 2015 Photos and measurements would be good, Larry. I'll concentrate on the engine first, though. Looks like I'll have source a crankshaft as the main bearings slip on and off far too easily. The conrod has a bushes small end instead of needle roller so it looks like the engine has been hastily put together with odds and sods and never fired up. Bit of a challenge, this young lady! Quote Link to comment Share on other sites More sharing options...
tony27 Posted October 26, 2015 Report Share Posted October 26, 2015 Loose bearing diameter on the crankshaft can be fixed by having the worn area built up with hard chrome & reground, is something that I've seen photos of being done on rare mx bike crankshafts Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 26, 2015 Author Report Share Posted October 26, 2015 That sounds interesting. I will investigate crankshaft repairs. Cheers Johb Quote Link to comment Share on other sites More sharing options...
feetupfun Posted October 27, 2015 Report Share Posted October 27, 2015 A local engine rebuilder here makes replacement crankshaft halves as an alternative to the build-up/grind back technique. Both will work 1 Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 27, 2015 Author Report Share Posted October 27, 2015 I'm happy to explore all options. I think I'll need a conrod kit too as the bushed small end does not apear to be standard. I'm wondering if the crankshaft is not from a Model 10? Does this guy have a website? John Quote Link to comment Share on other sites More sharing options...
woody Posted October 27, 2015 Report Share Posted October 27, 2015 I'd be surprised if the crank from one of the other 250 5 speed models wouldn't fit, some were single, some double main bearing on the clutch side. If you're in the UK have you asked Bultaco UK Quote Link to comment Share on other sites More sharing options...
blutaco Posted October 27, 2015 Author Report Share Posted October 27, 2015 I haven't actually asked Pete at Bultaco UK. I will now! The frame issue is now secondary, for the time being. Having a crisp sounding 4 speed engine running again would be a moral victory.... Quote Link to comment Share on other sites More sharing options...
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