February 29, 200818 yr As many of you may know the engine side covers are held on with an odd sized screw (at least odd to everyone I talk to). It's an M7x1.0 in both 55 and 38mm lengths. So far I have had no luck sourcing these. Are these even available from dealers in Spain? We're almost to the point of turning down M8 sized bolts or, God forbid, tapping the holes out to M8. Help!
February 29, 200818 yr Dave, M7 is unusual but not THAT unusual. I know that years ago I sourced M7 bolts in Stainless from a local warehouse called Metric and Multistandard Supply in Dallas. I think they are still around for the lookup! I'm sure they have minimums nowadays! Hope that helps!
February 29, 200818 yr Author Dave,M7 is unusual but not THAT unusual. I know that years ago I sourced M7 bolts in Stainless from a local warehouse called Metric and Multistandard Supply in Dallas. I think they are still around for the lookup! I'm sure they have minimums nowadays! Hope that helps! According to a cursory search of their website they don't have anything listed for M7.
February 29, 200818 yr What type of head is on them? There are a couple of guys around that specialize in restoring old Monts here in the states, what about the fellow at Bultaco West?
February 29, 200818 yr Author Jared at Southwest said he takes them off old engines. The originals are crossheads. Ideally we would want to replaced them with socket heads. Have not tried any of the Bultaco dealers as one would hope that they don't want to deal with old Montesas. So far I haven't found any screwy screws on a Bultaco. I got an email back from Metric and Multistandard Supply in Dallas, they said, between chuckles, no way. I believe a M7 is slightly more common in Europe, so here's to hoping it is.
March 1, 200818 yr i CHECKED AT THE LOCAL STORE AND COULD NOT FIND ANYTHING BUT M7 HEX BOLTS . ooPS But intrestingly enough, it looks like a M6 time-sert thread insert will pretty much screw right into a M7 hole to reduce it to M6, although I do not have a piece to try it on. A M6 helicoil insert may work as well! Then you could go titanium!
March 1, 200818 yr This may help !? http://enginescrewkit.free.fr Thats the homepage of were I got a great set of stainless allan bolts for the boys ty80 . There is contact info and they maybe able to assist in your search . Fantastic quality hardware ... Hope it helps !!! Glenn
March 1, 200818 yr Author i CHECKED AT THE LOCAL STORE AND COULD NOT FIND ANYTHING BUT M7 HEX BOLTS . ooPSBut intrestingly enough, it looks like a M6 time-sert thread insert will pretty much screw right into a M7 hole to reduce it to M6, although I do not have a piece to try it on. A M6 helicoil insert may work as well! Then you could go titanium! I had thought of that, and that is on the table as an option. Thank you.
March 1, 200818 yr Dave, OSSA MAR handlebar clamp screws are M7 x 1.0 hex socket head. I will check later tonight re the length. David
March 1, 200818 yr Hi I found a local supply with M7 bolts I machined the head to fit, cut a straight slot for a screwdriver and cut the bolt to length, it works fine. Living in Portugal is a pain for Montesa spares.
March 1, 200818 yr Author HiI found a local supply with M7 bolts I machined the head to fit, cut a straight slot for a screwdriver and cut the bolt to length, it works fine. Living in Portugal is a pain for Montesa spares. What is the spares situation in Spain like for the older Montesas? I think for several of the makes the supply is better in the US. Yes, we've tried that. Can't find M7 long enough, even with hex head. Thanks. Edited March 1, 200818 yr by swooshdave
March 2, 200818 yr Dave, It looks to me as though the diameter on a M6 allen head screw is right at 10mm and as long as that is not a problem I myself would be inclined to see just how well a standard M6 helicoil tap fits those holes. As long as the tap fits the hole, the helicoils will work well and you can get near perfect screws in steel or stainless. The M6 should carry plenty of torque, up to around 88 in/lb as I recall, which is more than a standard screwdriver will provide unless you use an impact in them. The M7 will probably only take about 110 in/lb max anyway I would think. But ultimate load should not be a problem as long as those cases seal up properly. On the other note, the place I checked had the M7 bolts in 40 and 50 lengths. There is nothing wrong with helicoils, did you know that ALL piston aircraft come with the things factory installed in the spark plug holes for durability!
March 2, 200818 yr Author As mentioned before, inserts are an option. I'm waiting to here back from the Ossa folks. It seems like there are quite a few Cota of that vintage running around. Are the the spares that dear?
March 2, 200818 yr OSSA MAR handlebar clamp screws are M7 x 1.0 x 55 long (from end of screw to underside of head) and the thread is 20mm long Dave This OSSA person is the same person who fixed up their M49 at about the same time as you did yours. David Lahey Edited March 2, 200818 yr by feetupfun
March 2, 200818 yr As many of you may know the engine side covers are held on with an odd sized screw (at least odd to everyone I talk to).It's an M7x1.0 in both 55 and 38mm lengths. So far I have had no luck sourcing these. Are these even available from dealers in Spain? We're almost to the point of turning down M8 sized bolts or, God forbid, tapping the holes out to M8. Help! Found these type fastenings are often available from aircraft supply places.............suppose they are used to reduce weight over M8, but still provide increased strength over M6.
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