Check that the needle circlip is held under the spring held retaining plate and that the cable is located correctly in the slide.
Cable should exit the carb top at the 10' o'clock position, always put your fingers on the float bowl to feel the slide returning to fully closed after refitting the tank.
If the above doesn't cure it check the floats, float height and fuel valve assy.
Sounds like the circlip above the retaining plate to me. (1988 IOM 2 day Yam TY250 )
You don't need the tool at all, I did both my forks this weekend and once I'd cracked the allen bolt off on the bottom I simply applied pressure to the "nut" using a length of 22mm plastic cable conduit. It wasn't perfect by any means but I did both legs this way without any problems.
The Breedon piston when fitted in a mh349 needs the ports putting in the skirt and the ring gap pins are in the wrong place. As for the 330 I have no idea but if the bore pin and compression height are correct then it's an option. Try Millers or in motion as they both have pistons from time to time for the 349 and may be able to help with the 330.
Cheers for your reply, I have measured the bore and piston/bore clearmance and decided to put a set of rings,pin and small end in, supplied by the helpful Kevin Breedon. He offered to do all work to modify a new piston FOC but didn't have a 2nd oversize available.
Looking forward to start the rebuild soon, will post pics as I go.
It has a 20" front wheel with luckily a virtually brand new tyre. The bike is currently at my dads (too many bikes, not enough space !) so I'll have a look for the make of the tyre - might be a help
cheers
John
That looks like a MkII to me, I think the Whitehawk I had in 82/83 was a MKIII which had a box section swing arm, don't see any other differences though. A great little bike, would love to own it again now!
Bought a set for my 330 a few weeks ago, top quality kit and very reasonably priced, he sells a few other well made and good value bits of twinshock bling as well.
If its the one up in Thurso I think its a 2000, showa forks and caliper on top of swingarm not inboard. You'll need front mudguard and bracket too. Room for bargaining.
Excellent first bike in my opinion, as above expect to replace dog bone bearings, All Balls do a complete kit for £65 ish.
Check usual, engine and frame no's haven't been tampered with (I "won" a 315 on ebay recently but the frame no's had been changed) Owner was genuine though and handed bike to Police.
I replied to you last night rather obscenly which has been deleted, the sentiment still stands by the way but for the record I'm not some lazy idiot who posts without looking first.
Not interested in a public slanging match, wasn't insinuating that you were as you quote " some lazy idiot who posts without looking first" but the original reply took you to a website with the manual you were looking for.
Judging by your posts you've been reading a certain Classic publication
I think I'm right in saying that the larger airbox were a Japanese Modification (Kato) and they are like the proverbial Rocking Horse poo, I did see one on ebay a couple of years ago and I lost out, as I fancy one too.
Just keep you're eye on ebay or try a bike breakers but even in the day they weren't that common, none of the Mitsui bikes ran them.
Rosey who posts on here may know better than me on this as he was riding for Mitsui Hamilton Yamaha back in the day.
Hi, Can anybody tell me whether the Montesa 349 piston fits the 330? They both share the same bore size (83.40mm) but the part no's I have found are one digit apart( As is the liner). I recall from posts on TC that HondaRS had to mess about machining slipper ports and piston ring grooves to get a piston to fit.
The only aftermarket piston source I've found is here:
Cheers for the input Guys, just asked for my own piece of mind before I start ordering all the bits I need that it is a viable proposition, I'll strip the top of the motor for reassurance too I think, Mains seem ok from Flywheel Up/down but there is noticable backlash when rotating, hoping this will be small end.
I've experienced first hand the difference between a competent welder and someone who claims to be able to weld, trouble is the only bloke I know that is competent is 300+ miles down the road!
Take heed of the advice on here and get rid, I had a 2 trial old Iris snap on my TY250 mono half way up an 8ft waterfall, not a nice experience coming back down with no engine braking let me tell you. I was fortunate enough to avoid injury and damage to the bike (Crankcase protector fitted) but vowed NEVER to use IRIS again.
I was about to start a 330 restoration shortly having bought the bike a couple of years ago. I knew that the Swing Arm bearings were shot when I bought it but on closer inspection I can now see that the chain has eaten it's way through the underneath of the swing arm at the pivot/ bearing area. There was no rubber fitted and the manual doesn't show one that I can find.
Where might a find a replacement or can anyone recommend an engineering workshop that could repair bearing in mind that the swing arm is aluminium. Does the 242 swing arm fit?
Also found the fork casting around fork pinch bolt had been glued back in place and fell off when I prodded it! The other leg has had the torque arm mount welded back on, not a great start is it!
Don't forget that the Scorpa SY250 uses the Z lump, so a Scorpa Manual will provide engine detail. I have a TYZ manual that I could refer to for you for anything specific,
No its different to the air cooled mono stand. It is all aluminium and made from two sections of tubing of different diameter and a pivot end piece machined from solid aluminium. There is an inverted aluminium cup on the bottom end. They are extremely flimsy. I remember having to straighten mine after every trial, and having to have cracks welded many times. Pretty sure I will have a decent photo at home but have not had a chance to look yet.
Sorry, but I have to disagree with you here, I have had many monos and currently have a Pinky and a TYZ and they both have the same side stand, (not that I leave them on as all trials bike stands aren't up to much in my view) See here
I think I'm right in saying its the same as the one fitted to TY air cooled mono, R or L model not S or N. I have several somewhere, PM me if you need one.
OK I thought I'd seen it all after the recent Majesty sale on ebay but this takes the biscuit. £6000 for a bike which wasn't rated when it was new and sold for about £1400, add a nice Mick Whitlock frame and 25 years later it's supposedly worth £6K, Crazy. Good luck to him but I thought the philosophy behind the twinshock seen was sensible sections and bikes at sensible prices?
Thanks for the replies lads, special thanks to Billy Craig for such a detailed and informative reply, although I was worried about your comment about my diet as it's probably not the best at the minute! I may well be in touch when I get a date for the op.
Iain, thanks for the support and well done for finshing the Scottish after all your Shoulder injuries. Are you riding this weekend at Perth?
I'm due to go in for a shoulder replacement(copeland) shortly due to severe osteoarthritis, what I would like to know is, has anyone else has had this operation and managed to get back on a bike? How long did it take, do you have any tips on pre/post op treatment, exercises, slings etc? For info I'm 39 ( which is young for a replacement apparently) and will be treated by Professor Len Funk.
315R Carb Issues
in Montesa
Posted
Check that the needle circlip is held under the spring held retaining plate and that the cable is located correctly in the slide.
Cable should exit the carb top at the 10' o'clock position, always put your fingers on the float bowl to feel the slide returning to fully closed after refitting the tank.
If the above doesn't cure it check the floats, float height and fuel valve assy.
Sounds like the circlip above the retaining plate to me.
(1988 IOM 2 day Yam TY250 
)