slogger

I have experienced to the dreaded kickstart stop cam penetrating the outer case of the flywheel area... Stripping the bike down, this looks like the previous owner had it welded up previously but this has bot held up. I have a local welder recommend by the club but was initially hoping that this could be done with the kick start shaft in situe (not the case)...... A was also hoping that the kickstart shaft was easy to remove (not the case)!!! So is their an article or a top line step by step guide to strip this down? I am fairly competent with a set of tools but have never split a crank case on a 2 stroke before....

Advice happily received! I am currently helping a friend who is getting into biking on a budget! He has been offered a Sanya SR125 for £200. Its been stood up for 4 years (its only 5 years old!!!!) and has only done 1800 miles. It was a non runner but we agreed with the owner a £50 deposit to allow us to take it away and see if we could get it to run. So after a few hours of playing it starts, runs, all key electrics work (starter motor and indicators need investigating) but after giving the carb a really good clean (including all jets out) and new fuel, it is still bogging down when rolling on from idle to 1/2 revs quickly. A gradual increase allows it to rev cleanly and at all points on the rev range it runs really nice. Interestingly if the choke is in 1/2 open it will rev through OK. The key points to note are as follows: Changing the mixture screw position does not really alter the problem Above 1/2 revs the bike will pick up on a rapid throttle open clean, the problem is only from idle to 1/2 The carb - this is where it gets interesting! The slow idle jet in the float bowl and the air screw are off set by about 7 mm although in the main throttle body their are two air holes, one directly above the jet and one above the mixture screw. If you put a piece of fine wire up through the jet housing it appears to hit a "step" and if you hold it to the light you can not see anything BUT of you blow a high pressure air line thought it BOTH holes in the main carb body exert air 9and I also filled it with duck oil as a tracer and this came out of both holes) My immediate impression is that the hole above the jet is still blocked due to the presence of no light and a piece of fine wire not passing through Would appreciate other peoples thoughts ? Carb is marked as a Dekni Pz26 YB40NE18 Rob

Many thanks, great to see the results again! Was it a separate route for inters and seniors ? I really cant remember as I was only 13 ???

If you cant upload a paper copy would be great ? I can PM my contact details ? Or can give you an email address or fax number to send a scan copy to ??

Myself and my brother were very fortunate to compete in the 5th Annual Aberfeldy 2 day trial on the 17th and 18th July 1982 on the year when they allowed a youth class. As well as a fantastic experience for 2 young teens (we lived in Bristol so a trip to Scotland was just incredible) it was one of those competitions that was a great learning excercise. The event was held by the Forfar and District Motor Club Ltd Last week my brother showed me a copy of the original program with the adult and youth listings but we are unable to track down a set of the results. If anyone has a copy (I know its a long shot), it would be really appreciated.

hmmm, took the stator off and there was a LARGE lump of metal behind it (about the size / shape of a 10p piece. Located this to be the welding that had previously been done on the case where the kick start punches a hole thru it. Wonder if this is disrupting the magnetic field !

Its now personal! Have put a new mikuni on her, new points, condensor, coil, plug cap and plugs and still running rough. Will start and tick over but if you gradually increase revs slowly at about 1/8 throttle she feels like she is not drawing fuel if you increase quickly she will rev past this part but has the odd missed beat. Have checked the carb and tried master jet on 1 size up. Now in process of having electrics apart again. Points were opening slighty early but stator screws as seized / rounded. Really need an impact screwdriver!

Ordered ...................from motocarb

Much fun had this morning....more so to learn that fix as for some reason the spark had come back!!! 1) Checked had a spark with existing set up - check 2) Flywheel off (with correct puller) 3) Replaced condenser with new one (after learning how to solder!) 4) Replaced points with new set 5) Spent 30 minutes finding TDC, 1.8mm BTDC, setting the points, discovering that the points close up when you remove the flywheel, setting the points again, taking the flywheel off again, trying to undo the stator bolts (as the points are opening slightly early, realising that the stator bolts will round off on the heads if I dont use an impact screwdriver (so left as is) 6) Making sure everything is tight and routed right under the flywheel 7) Put flywheel on and kicked over - hooray still have a spark 8) Put tank on and kicked it over ............ it started and ran ! Thanks to everyone for your help, I dont think it is 100% but it has been my first attempt and now I have the confidence to press on.. Now onto ebay to look for a new carb !

All, Many thanks for the comprehensive advice. Have ordered a flywheel puller and had ordered a dial guage (but not sure if Im going to need it now.....). Did kick it over last night after removing one plug to ease the compression (was kicking it over with both plugs in and a spare plug in the cap to ground). With the black lead connected to the coil I did get a good clean spark ! Am going to strip it all down and check everything incase it has moved on the woodruff etc. Will let you know how I get on ! thanks again Rob

Beldane, thanks for all that. Just so I am clear: 1)Timing completed with flywheel on, lined up with crankshaft via woodruff key 2)Points gaps set at point where points are open. Set to 16 thou 3)On compression stroke the points should start to open at 1.8mm BTDC question, if they open earlier / later, where is the adjustment made if the woodruff key is a fixed point ??? Also, have located a flywheel puller but regarding the dial gauge, all of the ones I can find dont appear to have a threaded adapter for the plug hole ? Is that correct (ie that have and 8mm diameter stem). Have included a link to one for validation ??? http://www.axminster.co.uk/axminster-axminster-dial-gauge-prod21170/

Only had a brief glance, so my statement was an assumption. What am I looking for both on the flywheel and point of reference to allign it to ??

Cheers for that. With the timing out, I can understand the misfiring earlier but that was before the off which caused the power loss. The fact that current is flowing from the flywheel out to the tip of the black lead (into the coil) but I am getting no spark when this lead is connected to the coil pack would indicate a problem at the coil pack end ? Also I have read in other posts about "timing marks". I can not see any on the outer of the flywheel, where would I find them ??

Would also be interested to know how to remove the flywheel and how to check timing, points etc? Have removed the nut holding the flywheel to the crankshaft but I assume the flywheel either needs a puller or is on a taper / reverse thread??

After enjoying a full competition on my recently purchased 348, things turned the corner during practice yesterday. Firstly the bike was misfiring under load at about half rev's. I put this down to the incorrect carb fitted and wondered if the jetting / mix was wrong but nothing had changed since the last competition although I was not entirely happy with the performance during the comp but it did run reliably throughout. Then after riding up a rock staircase and going off line on my third attempt, the bike came down with quite a jolt, I ended up in the stream and the bike would no longer start. The bike did not rev out it just ticked over had a very brief increase to about 1/4 revs for a second then died (the bike ended up inverted) and no water got into the exhaust. Having changed the plugs etc, I can confirm that their is no spark. I have isolated the kill switch so that it is just the black lead out of the flywheel case into the coil and a single coil HT lead to the plug. If I remove the black lead to the coil and attach a wire with a bulb going to the frame I get a strong illumination. The points are also about .20mm when closed and using the sighting window in the flywheel are opening and closing OK. When I bought the bike the receipts said that it had a new coil about 2 years ago from Sammy Miller, the brand appears to be WAT YONG? So a few questions: 1) Any other tests I can do to prove that the flywheel element is OK and any other tests of the coil 2) What is an advisable replacement coil 3) Could the immediate deterioration of the electrics be linked to the poor performance earlier? Am loving the bike but this is a bit of a pain! The bike came with an incorrect carb and I am planning on swapping that but I need to nail the electrics first.... any advise is appreciated. Whilst I am ok with spanners my electrics knowledge is limited so please explain in detail...... Rob

I have taken the brave/foolish/mad (delete where applicable)decision to purchase a sidecar off of ebay to pair with a Montesa 348. Having ridden schoolboy twinshocks in the 80's, mono more recently and then moving back to twin shocks I suddenly had the urge to give sidecars a go.... I am wondering if the sidecar enthusiast's can help with the following: 1) What are the common mounting points for the chair to the bike and how should I approach a Montesa 348 2) For a newbie what are the basics and how would you build up the practice ? any help appreciated Rob

Choke sorted, the assembly was all there just well seized. Stripped and re-assembled and working fine. Fuel leak not a good story though.....thought it was the filter/washer but the thread that secures bowl that connects the petrol pipe to the carb has a stripped thread! Tried to tighten it and out pops a helicoil! What to do now ?

Yep, its a UK bike. Fibreglass cover over an alloy tank

How did it go?????? Can also highly recommend both Aqueduct and Border.............

Have just noted that the carb also has no choke. The shaping of the carb body suggests that it is capable of taking one but where the choke lever would normally be is what appears to be a blanking plate. Any thoughts...

The Mont 348 I have recently purchased has Air forks on the front and I assume an after market set of Betor Gas shocks on the rear. As the bike is in very good condition, I have no reason to go playing around with these from a maintenance view point but it would be useful to know the following: 1) What is the basic construction of these - I assume it is still oil filed with additional dampening being delivered by air pressure 2) How do people use the air element to set their shocks and forks up Rob

Having just picked up a 348 in fairly good nick,one area that could do with a little attention is the tank unit. The fibreglass is thin around the area where your legs rub and there are a few rough edges that could do with smoothing / filling. I have had some experience of fibreglass sheets and epoxy based fibreglass fillers in the past but wondered about peoples experiences on the following: 1) What do you use to both strengthen the main structure (on the inside of the tank) and reshape/fill any cracked / thin areas on the outer side 2) What is the basic technique / materials used to respray a fibreglass tank cover thanks in advance Rob

I have just purchased a Montesa 348 which appears to be fitted with a Dellorto VHBZ carb as opposed to the original (i believe) Amal. This got me wondering, how interchangeable carbs are and how does changing the carb change the behaviour of the bike? Any knowledge of this subject would be of interest as the previous owner purchased the carb off of ebay and I am wondered if a different carb would change the characteristics of the bike.

I am lucky enough to be picking up a Montesa 348 this weekend as I am moving over from mono's to good of twin shocks. The last Mont I had was a Cota 123 back in the early 80's when I rode school boy... I am hoping owners of 348's can educate me to the normal maintainance routines (eg oil chages, grades etc), frequency, things to keep an eye on or strange quirks. I thought I read somewhere that the gearbox has a separate oil fill to the clutch? its these bits of knowledge that will help..... thanks in advance Rob

After much frustration the 240 I recently bought (which had been stood up for at least 5 years)is now running sweet! After isolating the poor running to a loose kill switch wire (phew, was ready to replace the electrics / crank seals)the bike had a full practice ride yesterday and runs sweet. I now need to allocate the budget to a number of immediate replacement items to get it ready for its first comp, then I can prioritise time/money of a gradual rebuild / restore. A couple of quick questions in order to address two items without any spend: 1) Are the standard shocks (Marzocchi) rebuildable. At present they have no dampening but there does appear to be a large nut by the damper rod that suggests they can be rebuilt 2) The petrol cap has sheered just inside the cap cavity where the breather pipe attaches. This is resulting in fuel spilling. As a cap is