naichuff

No they are to hard for serious comp use.

You do not say what bike they are fitted to. I use Pirrelli's on my Bulto with tubes front and rear on tubed rims This is fine as it is only used on the road and the odd off road trail ride as they are harder wearing tyres. If competeing I use Mitchilin on the Beta tubed front tubeless rear .

From the photo it does not look that bad If the coil resistance are good then ok do not know about that the condencer bit iffy Not so sure with alloy back plate depends on the corrosion on it. It may clean up as with the flywheel

Modern fuel does not have a long shelf life. Drain it off clean the carb out and put fresh fuel in. Vintage bikes that are stored over the winter have the same problems I always drain mine after the season is done and run the carb dry as it can block the jets and galleries in the carbs. Old fuel will wet the plug but may not burn. New fuels also tend to absorb water and corrode older fuel tanks and fuel systems on the vintage bikes are left with fuel in them.

When I fit gaskets and seals I usually just use grease Make sure both mating surfaces are flat and clean and the cases are pulled up evenly Remember an air cooled engine will run fairly hot when trialing.

There is two adjustment point 1 the elbow that screws into the carb 2 where the cable enters the elbow at the top mine is fitted with a slow action Domino throttle it replaced the Beta one The problem could still be the cable stretched

Hi There is slight differences in the rear engine mounts on some models as some 350 motors sat further forward than the 250 My 175 motor is almost touching the swinging arm pivot pin That not to say there is not a problem with the swinging arm

I have used Amal web site for a new monoblock and a type 76 for my vintage and classic bikes www.amalcarb.co.uk Both carbs just fitted the on connected the fuel and cables and the run well no adjustment needed.

Remove the black covers behind steering head also remove cover where the cables and pipes are in front of fuel filler The CDI unit and regulator are in there beside the next to the rad filler cap Mine also failed when the mouting came loose inside the box It also holds the earth for the fan( I think) If you Have the rad off look up in there it is the blue box in the middle It is a tight fit

Yes the fuel will run out the over flow pipe mounted at the bottom of the float bowl the pipe exit is behind the gear box I had the same problem checked the float height replace the float needle valve Also I found if I slowly turned the float bowl upsidedown one of the floats stuck My Beta filled the crankcase full of fuel and hydrauliced If I remember I think the fan earth is at the regulator but then mine has been rewired

Also check the fuel tank breather

yes and remember the gasket under the seal carriers The o ring is very thin and can be easily missed out or broken

Nice pics how can I get copys of myself Ta

Just a thought is the M20 or M21 gearbox what you may need to find even better if it was ex WD type

Scottish classic racing trials ( see web site ) are also mostly in the west The lanarkshire club although the HQ is in Edinburgh the trials are all over (see web site) You could try the Bob Mc Gregor Academy run by Ian Shankie near Dunlop Was at a trial there last Sunday I think they have a web site

The fan should suck air from the front and blow it out rearwards assisting the air through the rad when travelling forward If not it will be fighting against the air flow

A diode is like a non return valve and lets current flow one way but not return(AC) This converts it into a pulsing current but uni directional If you think of current (amps) as the rate of flow like water from your tap. The voltage as the pressure of the flow An example is a tap run of the mains water supply ( high pressure) or that supplied from a header tank(lower pressure) Some diode packs on bikes are also designed to control the voltage as the revs rise so does the voltage out put from the stator This could damage the electrical equipment ie .fan ect

I have seen pursang rear hubs that the sprocket can be fitted both sides so the brake can be swopped over

From memory I think the clutch centre is on a splined shaft and is held on with a single 16mm nut You may need to hold the clutch centre Watch the flat roller clutch thrust

Carb Id NoPHBH26CS Main jet (standard) 135 Slow jet (standard) B46( upper) 46 (lower) Jet needle clip 3rd from top Float level 18.5mm Air screw intial opening 1 turn out from Montesa manuel 97.>99 315

Washing up liquid has a high salt content so next time you might need a new rim Water salt and alloy do not mix

Just been looking through an old copy of OBM saw an ad for Villiers Services tel 01384265797 closed wednesday I have not used this company but worth a try

There were three types of rear muffler A small triangular type circa 72 > It fitted between the shock frame and swinging arm This was updated by the Banana type It was a slim curved type exiting at the top of the shock and was superseded by the the type that had the boxier end Cannot say for certain when each type was fitted would be fitted but your one was not fitted for long. I had a 76/77 250 it had the bigger tail muffler so 75/76 could have the non bulbous type.

There is thrust washers at either side of the small end Never had to do a big end but the Hayes manual exploded view shows thrust washers But it is only a rough guide to all Bulto motors including Pursangs and Alpina

In the uk Montesa's were sold with alloy tanks and fitted with a cover I see them in the Miller products catalogue issue 3 This is a one piece tank cover seat unit Any help?