Hi, Just taken delivery of this bash plate for my 1981 349 51M. Does anyone have and info on fixings? Nothing came with it so I need to acquire the suitable screws, bolts or whatever. There seem to 9 possible fixing points. Any info gratefully received.

Neil

Take a look here: http://montesakingscorpion.blogspot.com.es/2014/10/trabajando-con-los-despieces-de-montesa.html

It's an explanation on how the Montesa manual works. Hope Google Translate will be of help.

My engines out at the mo, can take photos later on - they're countersunk machine screws with nylocks on mine

Thanks Kingscorpion really helpful.

I have done a google translation of that part numbers explanation using google to keep for reference.I have attached it in case it may be of use to anyone.

Also thanks Turbofb that would be helpful when you get time.

Montesa part no explanation translated with google.docx

The front two pairs of holes on the curved part should be fitted with countersunk Allen headed bolts M8 and flat washers with nylon nuts. The bolts must not protrude through the nuts by more than 2 threads, apart from weight saving there’s less chance of the bolts puncturing the crankcases. The rear four holes take the same sized bolts again with flat washers and nylon nuts. Don’t tighten any bolts until all are installed, you may need to get someone else to help you as the frame sometimes ‘springs’ especially when the engine is removed. You may not have noticed this when removing engine but the frame can move by up to 5-10 mm. Long rods or Philips screwdrivers can be used insert into frame lugs and enter tip into engine mount lug and gently apply lever force, you’ll get the idea when you start the process. Hope this is of help?

Hopefully this provides a little help:

The bolts appear to be M10x30 countersunk hex that have been cut down (I don't think 20mm ones would be quite long enough, certainly at the front), they're stainless on mine.

Hmm. I offered it up this morning and it didn't line up. The whole thing has perhaps "spread" 

The bike came with a bashplate that hung from the rear cross member where it shoukd bolt to.

Any idea how I should proceed?

The engine is in so might it be prudent to take the engine out and then fit the plate before replacing the engine?

Thanks for the replies.

Neil

Edited January 4, 20188 yr by netley
Spelling

I'm afraid the Google translation is not very accurate. If you find the article useful, I can try to improve it a bit.

I personally did get a good idea and it has helped a lot but I'm sure a better translation would be welcomed.

Thanks.

Neil

Like I mentioned you will need to coax the frame and engine together. I find the method I suggested works well by levering the frame gently into alignment with the engine mount holes. Alternatively you can fit the front engine bolts to the frame and either push the engine back towards the rear mounts on the frame or use a ratchet strap. This springing is not unusual and usually can be overcome by careful application of pressure. You may also need to ensure that the bash plate/ sump guard is not bent or twisted. It may also be too long which will require you to bend it at or near to the front radius. 

Looking at mine, I recon getting the engine out would be essential to getting the frame corrected.  Also while the engine is out it's worth checking that the swingarm centre support is actually in the centre, and not off to one side like mine was (which made getting the swingarm off interesting, would have been properly difficult with the engine in).

I have offered it up with engine in before I start anything. I put the far left hand screw in loosely and then took this pic from the right hand side looking down. As you can see, these holes don't line up, bugger !

Am I missing something or have I just got the wrong one? I was told it came off a 51M which is what I have????

51M covers more than one model (IIRC the Cota 348 is also a 51M, for example), looks like it can be worked on a bit to get it to fit though

What has to be remembered is that all these Spanish bikes were assembled by hand and this included the hand fettling to make components fit. The frames may have come off a jig but many of the other components were supplied by small one man/woman businesses so fit and quality was down to who ever assembled the bikes. Mr Honda changed all that with a big wake up call called production line acceptance.

Dam those pesky Europeans ?

Looks like some fettling is to be done then.