belldane

Jaan You have not lived until you pull an old Monty engine apart. The seals are very easy to replace but beware the primary gear is a very frustrating job to get off. If it is the engine crank seals that are the problem, which I don't think they are, from the info you have provided and in such a short time from going OK to going bong, I would be looking at other things that people have suggested at your question. Check air leaks, carburation and electrics. Have fun mate!!!! I have done it many times.

No worries. Take it off again tomorrow and put it back in. You will be a wizbang on 348 exhausts in no time. See ya mate

Geez the motor must have sounded like a tin can full of nuts and bolts. If your Cota is a 70's vintage go to southwestmontesa.com. On the home page on the left hand side, scroll down to Repair Guide and you will find a full Manual for Montesas which you can download for nothing. If that does not answer your question, send Jared Bates (the owner of the place) an email and he will give you the answer. Regards

Just make sure the tank/seat assembly is off the bike and with a few twists and turns (having your tongue out of your mouth and thinking of a few choice words) it will go in!!

You can also try Jared Bates at southwestmontesa.com. He is a great bloke to deal with and the prices are pretty reasonable. I have restored a number of old Montys over the years and have always been able to get the parts through him. If he does not have the parts he can source them elsewhere.

There are no other seals inside the cases. I would put all back together and if anything leaks oil replace the seals then which is easy enough to do. After replacing the shifter seal, which you already replaced, the only other seal is behind the countershaft sprocket but like I said try it, if it leaks, replace it.

Dave Never thought of that. Good idea but can you see the cam and the heel through that little hole? I will have a good look next time I have the cover off. Thanks for that

I always thought that torque was low down power. The sort of stuff you need to get over obstacles at low revs with just a blip of the throttle. 5000 or 6000 rpm. Come on mate you have to be joking aren't you?

Geez you two people must be purists!!! I tried doing the timing on my 348 the same as you. connecting wires and disconnecting them, ommbuzzers, etc etc. and by the end I got sick of it. If you have a good spark and provided the points are not worn this is what I do. File the points with a very fine grade wet and dry paper and clean them afterwards by inserting a bit of paper dipped in metho. Keep on doing this until the points contacts come up clean. Turn the flywheel clockwise until you see the points opening to their highest point and adjust between 14 and 16 thou. Take the plug out and put a dial gauge in its place. Rotate the flywheel anti clockwise and then clockwise to find tdc and lock it. Turn the flywheel again anticlockwise and when you have the highest opening of the points insert a bit of cigarette paper between the points and slighty go anticlockwise again until the paper is tight between the points. Now the good bit. Very slowly turn the flywheel clockwise having a hold of the ciggy paper and looking at the gauge, and from memory points on the 348 should be begin to open at 1.8mm btc. (Correct me if Iam wrong) You will notice a slight hold on the paper when the points begin to open and firing in the cylinder occurs. This may sound a complicated but practice makes perfect. I have been doing it on all sorts of bikes for over 40 years and it works for me. See ya

All manufacturers of trials bikes developed their machines by having works riders (ie riders who worked for the companies and got paid good money, who competed in events and gave advice on changes needed to be made to make the bikes more competetive) From the engine number you have provided, I tend to agree with Vintage Cota that you may be the new owner of one of those bikes. You lucky man!!!

Hi There is no clip holding that basket in. It is a pressed fit into the shaft and you will need another puller big enough to remove it. If you don't have a puller I would suggest that you take the engine to a bike shop as it is probably going to be cheaper than buying the part to remove it. While you are there get them to remove the primary gear as well. If you think getting the basket off is hard, wait until you try to remove the primary gear!!!! I wish you luck my friend

Thank you all for your suggestions on what the problem may be. I will pull the carb out when I get a chance and do as you suggest. However, I still maintain that it is sucking air in somewhere (high revs when it starts and then settles down) and when the engine gets warm wherever the air is getting sucked in, closes up. I will keep you posted on how I go.

Dave Pilot jet is fine. I have cleaned the carb about 10 times now. If it was a cloggled pilot jet, how come it starts first kick after warm?

Hello Everybody I need some help to sort out my 348 Cota. I don't ride it that often but when I try to it will just not start unless I take the plug out, pour a bit of two stroke down the plug hole and then it will go revving its dinger off for about 30 seconds and will settle down to normal revs. Once it is warm it will start first kick every time. I suspect that it is sucking air in somewhere but have no idea where. It does not like choke to start and runs fine after it settles down. I replaced crank seals, rings, bearings, ect, ect, recently, points and timing are spot on, had the carb (Amal) reconditioned but just does not like a cold start. Any help much appreciated. Thanks

It is hard to work out what the problem may be from the description you have given. Like wayne said. It could be the crankshaft seals. It could also be carb problems, points not adjusted right or even a sheared flywheel key which is putting the timing out. I would start with the easy stuff first ie take the carb out clean it properly, blow every hole you can see, make sure the idle jet is not clogged, put it all together, turn the mixture screw 1 and a half turns from fully closed and see how you go. If it still does not want to go I would check the other things I mentioned. Failing all that replace the seals and you should be right.

To get the shaft out you will need to split the cases as there is a circlip in there that holds thw shaft in. Have fun!

Hi All I have a ty250a with the piston stamped 25. Does anyone know if that is the first oversize? Also trying to remove the cylinder, one of the recessed bolts has been nicely rounded by a previous owner. Any ideas on how to get it off please? Thanks for any help you can give me.

Hi all Just tolet you know that I have sorted the old TY out. I readjusted the points and timing, cleaned the jets out again and I noticed when I screwd the main jet back into the fuel bowl that the holes in the whatever which deliver the fuel to the jet could not be seen through the small hole at the bottom of the bowl. I just unscrewed it a bit and lined up the hole in the whatever with the hole in bowl, put it all back together and it is a different bike. I really don't know whether it was one thing or the other or both combined. Thanks for the help

You are right on the ball Feetupfun. I actually have two of these bikes built in 1974. One has the gear change on the right and the other on the left. Both bikes are identical to the one in the picture except for the groovy mudplaps.

You are right on the ball Feetupfun. I actually have two of these bikes built in 1974. One has the gear change on the right and the other on the left. Both bikes are identical to the one in the picture except for the groovy mudplaps.

Dave dix - crank case screw still there. I plugged it up when I started using premix. Will have to change crank case seals as the crankshaft bearings are a bit dodgy. Tony 283 - See above about the premix. New fuel was put in tank, spark plug replaced. Will check points and condenser tomorrow. I have to replace the crank bearings so will replace rings while I am at it. On the reed petals, they appear to open and close Ok. Just one thing, or two actually, the bent pieces of metal next to the reeds (the bent ones appear to be a bit rusty. Does this matter. The straight ones on the inside are fine. The other thing, when I took the reeds out I didn't notice which were on top. They appear to be the same either way they go in. Is that right? Stork 955 - exhaust was cleaned out a few months ago so I don't suspect that may be the problem. Feetup fun and Woody - Have got a dial gauge so will set timing at 3.1mm. Just another question please. I don't know if the TK carb has been fiddled with. The main jet which I assume is the one piece job with the nut at the bottom of the bowl does not a number for the size. If there is one there where is it? The pilot is 50. Does it sound right? Give me a Monty any day!!! Thank all for your help. I will get this b-----d sorted out. Ps Up until now I have been getting some parts from bultacouk.com. Do any of you know where I can get parts in Australia? Thanks again. See ya all

Thanks DGShannon You would not believe what I found on the net. A carb specialist suggested that you put the carb into a pot and boil it in water for 10-15 minutes. Clears all the gunk out and just blow all passages. I did that today and the carb is fine. Just one problem though, See my posting on TY250 problem!!!! This is driving me mad!!!

Hi all I recently posted a message about the old TY I am restoring. As some of you may know I managed to find an original carb for it on ebay (TK) I cleaned it it all up and came up superb. Installed it and to my dissapointment the bike still has no whoomph. The number of the motor is 434-008250 so I am pretty certain it is an A model (You experts out there correct me if I am wrong) The bike starts first kick every time, seems to have some power down low, but when you hit the throttle, just wont rev right up. I suspect that I may need new rings ( they have not been changed in about 25 years and I also thought the timing could be out. What should the timing be set BTD on an old A please. This bike is driving me to drink!!!! I have restored 4 Montesas which are now in the shed but this Yamaha is driving me nuts. Any help you can give me much appreciated. Thanks

Hello Guys and Girls I bougth a TK carb for a 250a from ebay but when I opened it up it was a mess. White milky liquid like clay came out of it everywhere. Petrol does not remove it! Any ideas please? Thanks

G'day mate I have just finished restoring a 348. Split the cases, replaced all bearings, seals. Everything that needed to be replaced was done. Parts are not a problem as most of them are still available. If you need any help email me at belldane@skymesh.com.au. See ya