Sick Majesty!

[scotty]

Hi Folks! having problems with my 250 majsety after doing a fun trial at earl shilton on sat night one of the sections involved a stretch of water (river!) which was quite deep in places! on the third time round the bike started to splutter and load up! after escaping the exit bank i made it to the van thinking the old girl had gulped a large amount of water (the villiers brigade merrily rode this section with the engines under water! ) anyway i removed the float bowl and removed any traces of water but the bike was still sick ie wouldn't rev properly or cleanly! anyway when i got home i removed the airfilter and checked inside the airfilter box all ok supprisinley dry! removed the ign cover and a lot of water fell out! ive sprayed the inside the flywheel/stator with wd40 but she wont start or run properly? anyideas? ive stripped the carb and cleaned throughly! could be the points/ condenser? of sheared woodruff key? its doing my head in as normaly this bike is super reliable! thanks scotty!

[diggin4s]

IF?

your carb vent tubes are long and/or kinked/plugged puff some air thru them and then diagaonal cut the tips(less chance of water/crud plugging end), your carb may not be having the the venting its required

[feetupfun]

The points may need more attention than just spraying with WD40 through the hole. I suggest removing the flywheel and drying out everything properly and cleaning the points properly. WD40 is good for displacing water but can cause problems if left to dry on the points.

You can judge if the ignition system is the problem by looking at the spark with the plug removed and resting on the head. It should be a light blue colour.

[yamahaty250xox]

The points may need more attention than just spraying with WD40 through the hole. I suggest removing the flywheel and drying out everything properly and cleaning the points properly. WD40 is good for displacing water but can cause problems if left to dry on the points.

You can judge if the ignition system is the problem by looking at the spark with the plug removed and resting on the head. It should be a light blue colour.

had the same problem on my ty,

try drying out the flywheel with a heat gun, and then use instant gasket to seal the casings to the engine

[scotty]

Thanks Lads! The sparks not very good ie white and it dosen't spark between the electrodes as it should! just around the bottom part(ceramic)

ill slit the vent hoses as mentioned cheers! if i use instant gasket do i still use the original gasket? ill pull the flywheel off tonight and have a proper look? how about electronic ignition is it any good? anyone using one on there bike? or keep the points set up?

thanks Scotty.

[woody]

Electronic ignition won't give any performance increase in terms of power output. I don't care what the theories are about better, fatter spark giving optimum performance at this or that revs, I've run my Majesty with both points and electronic and it runs the same. It's a 320 and doesn't need any more power anyway but what I'm getting at is that electronic doesn't magically increase torque output or turn a 250 into a 325 or a 125 into a 250 if you see what I mean.

What electronic will give is a consistent and reliable spark, built in advance (matter of personal opinion as to how beneficial this is) and a more accurate means of setting the timing. No points wear to give erratic running, no worries about failing condensors, corroded points when it's been standing, doesn't matter if water gets in as it will still operate. Basically fit and forget.

There are several options.

Find a TY Mono stator/coil/CDI and use that, it will work with the Majesty flywheel but will be a sod to set up as the keyways are in different positions on both bikes so it's not a simple bolt on job using the timing marks to guide you. Backplate slots may need to be elongated to get the stator in the correct position for the timing. Could prove a headache, depends how patient you are and how much messing about you want to do.

Use one of the aftermarket kits from Craig Mawlam but pricey now at about

[scotty]

bikes still sick! removed flywheel and cleaned the points in meths! checked points gap ok! bike fired briefly then just a put put! out of the exhaust! then nothing! plug now sparks bright blue/mauve spark! but its wet and oily? poss timings out/slipped etc! but how? dont really wont to start messing about with timing/ points gap yet as bike was running ok before i put it in the van!

but will need data as last resort ie btdc mm etc! woody im not looking for any performance gains! the powers perfect for what i want! just want reliability if i can get this with the points/timing set up right then thats cool with me! ive got an complete working stator set up some where in the attic! ill try this at weekend! thanks for th input so far! Nick.

[mollygreen]

Use one of the aftermarket kits from Craig Mawlam but pricey now at about

[woody]

www.tytrials.co.uk are doing Electronic Ignition kits for

Edited August 14, 2007 by Woody

[kevin j]

I was looking at retrofitting to a TY175 last year. One of the most knowledgable vintage riders in this country recommended an electronic package he helped develope. bob ginder at bjracing.com sells it.

I was looking at fitting an ignition from the early 80's Yam MX etc. til it was very well pointed out that replacing an old, well tested magneto technology with the first generation electronics technology was not the way to go for reliability! That made sense. So I dropped it all, but the newer stuff is well sorted out. Was too much for the value of the bike I had i mind, but have heard good things about it.

[samb]

I think your problem lies with the condensor . the bike will not run right unles the ignition timing is set correctly . Using a Dial gauge and a points meter . the point gap does not need setting . just a what time the points are closing in rleationship to the piston position .

the dial gauge should be screwed in to the spark plug hole using an adaptor , and the fly wheel turned until the piston is at top dead center the dial gauge needs turning so 3 mm is reading on the scale. the points meter( genuine yamaha meter )needs attaching ( red ) to the live wire coming out of the ignition casing . and the (black) to a suitable earth normally the engine casing . the scale needle wants setting midway on the open scale . then rotate the magneto clockwire until the needle goes in to the red ( point fully closed ) if the needle willl not go in to the red the point need cleading. Using fine glass paper and cleanig using meths or an evaporating electrical cleaner .

The correct ignition timing for a 250 majesty is 2.6mm b.t.d.c . there is also a 250 (s ) majesty which uses the standard pistion , but has had a new cylinder liner fitted to alter the porting .ignition timing 2.5 mm b.t.d.c .

the 320 majesty timing is set at 2.1 mm b.t.d.c . some of the later models had the back plate slottod and rotated .This stopped the engine from getting to top dead center and going backwards when ticking over in either 3rd 0r 4 th gear .

this is the procedure i followed whilst building all the majestys at john shirts from 1978 until 1984 .

[scotty]

Thanks Sam! Ill go with that ill change the condenser first! then set the timing! the bike was super reliable before the dreaded river section!

suppose thats always a good test! my bikes a 1980 yamaha framed would this have std porting and carb settings etc! it deffo has the std flywheel fitted and not the heavy one! the engine and chassis numbers match so should be all original?

Nick.

[micky]

Gents, this may have been covered but years ago my 250 Maj had a similar problem, it turned out to be moisture between the outer and inner shield of the ht lead, I only discovered it whilst changing the plug cap.

[scotty]

replaced the condenser and reset the timing! bike now runs perfect! thanks everyone!

[samb]

replaced the condenser and reset the timing! bike now runs perfect! thanks everyone!

scotty the early majestys had standard carb settings . with just the ignition timing retarded to 2.6 mm.b,t,d,c ( from 3.1 mm b.t.d.c ). But they had the heavier magneto flywheel weight fitted .

we also used the left hand carburetor off the early rd250 air cooled road bike . with the balance pipe blanked off . it has to be the left carb as this one has the choke pull knob .

a boost bottle can also be used which is mounted under the petrol tank , the rubber manifold off the early rd250 lc has the adapter pipe , and the same mounting holes .this was fitted to a number of competition bikes on the yamaha range YZ , IT and DT . this gives more capacity of the air fuel ratio , which is then pulled in to the cylinder .

THE 320 MAJESTYS had a slit cut in to the top exhaust side of the air box to allow more air flow .

there wasalso a full blown 350 cc majesty . but only for the factory riders . these had a lower 4th gear for better choice in sections . another good easy modification is to extend the clutch arm under the engine by 20mm . this can be done by removing the bash plate . lying the bike down onthe clutch casing side of the engine .this saves draining the engine oil removing the clutch adjusting nut and screw , mounted behind the magneto . the clutch arm can now be removed , and extended . refiting is reverse procedure . making sure the pip on the adjusting screw fits in to the recess on the pivot shaft of the clutch arm before tightening the lock nut up .

Sam