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Messages - bigmockuk
1
« on: July 24, 2023, 08:30:39 PM »
interesting point about the missing ring from beneath the valve guide,i could see why oil could be sucked down into the cylinder,yes i did fitted the new guide myself,did it years back on a cb125 twin,heating the head up in the oven till cooked lol and putting the guide into the freezer then drifting the guide home,it lined up nicely and im sure i remember fitting the washer first,tapped it in nice n straight using a drift that fitted on the outer shoulder where outer valve spring would sit then using course grinding paste until a nice even unbroken seat then fine grinding paste,ive heard your meant to recut a new seat but didnt have that type of equipment,but got a good seal good compression.
2
« on: July 22, 2023, 12:03:02 PM »
thanks guys,i do remember on just one occasion the bike was ticking over and there was one gush of air from the front left between the head and barrel,just that one time,might be worth taking valve springs off no1 and have a look and recheck head again altho it was the opposite side,no 4, that was slightly warped at the start,the smoking is not unbearable,just under acceleration and the plug was black sooty but no actual oil on the plug just like i say a mist on the piston crown,gonna have a good look at it today. will fit new gasket and inlet valve seal too,would it be better to use a small layer of gasket sealant before fitting the oil seals do you think?
3
« on: July 22, 2023, 12:00:58 AM »
i had to replace the inlet valve guide and valve on no1 cylinder when i first got the bike due to lots of sideaway movement! it just seemed to always be no1 smoking tho, i could try checking the barrel for any warpage? i had to skim the head a while back due to this,im toying with the idea of drilling the barrel and head oilways to fit small pipes to replace the need for seals i think it can be done if i can find the correct diameter pipe
4
« on: July 21, 2023, 11:19:28 PM »
thanks for getting back so quick,no1 cylinder smokes more than the others,when engine heats up and the others stop smoking no1 still smokes on acceleration,stripped the head off today,all pistons are dry except no1,the crown has a misting of oil on it,dont think its the valve guide seal as done not that long ago,new rings fitted too so im thinking oil is getting sucked past the seal,i dont like how these seals flatten the way they do but understand why
5
« on: July 21, 2023, 10:59:36 PM »
Had to strip the head off the 550k3 a few times for one reason or another and found each time that the oil seals between the barrel and head are flattened and compressed,first of all is there somewhere that does these seals without the need to buy a whole engine gasket set? and secondly is it possible (or has anyone done it) that instead of using oil seals that it would be possible to drill n fit dowels instead?
im thinking it should be possible to have tight fitting dowels which would allow the oil to pass up into the head without the chance of oil getting sucked past the seals into 1 or 4 cylinders?
6
« on: December 23, 2017, 10:07:13 PM »
so it can tick over with pressure still coming out but the harder the engine works the fault can show up,im gonna fit new exhausts gaskets again shortly so will certainly try passing a hose down each one for peace of mind! i take it the exhausts must be double lined and the inner liner has broken thru and warpped under heat? my no3 heats up and runs with choke on but cools down when choke is off then sits there with a slight cough/splutter.must admit tho no2 cools down a little when choke goes off but seems to run fine.1 and 4 stay warm throughout and even running.im sure i`ll get it ironed out if i treat each cylinder independently working thru ignition/fuel systems.these carbs were the worst ive ever seen due the bike being in dry storage for over 25yr,every passageway/jet was heavily blocked and took weeks to clean out,interestingly enough as i write this,the brass pipe on no 3 carb was blowing bubbles of fuel with float height at 14.5 so reset them all at 15.5 and it appeared to cure this.picture below shows pipe end filled with fuel which i understand should be an air passageway into the emulsion tube?
7
« on: December 22, 2017, 08:19:40 PM »
pretty sure mine is clear tho as plenty of compression blowing thru but its certainly one to look out for!
8
« on: December 20, 2017, 09:59:33 PM »
wow who would have thought of that happening? could that be seen from the top of the pipe ? am stunned that could happen at all !
9
« on: December 20, 2017, 09:56:11 PM »
I see what you mean rob about getting the tick over first then working on the cables.K2-K6 you bring up an interesting point,firstly its my throttle stop screw that is indeed in control but maybe just barely? i have no slack in any cable push or pull.i suposse they are both pull,one pulls the slides up and the other pulls them back down.im curious tho,if all slides are screwed tight to the one shaft and it bears on the throttle stop screw i would think it should be impossible for the cable to be able to close any slide even a fraction?Im getting what you mean by the space created under the slides.ive got a theory but could be wrong,when i stripped carb bank i tapped out the spring loaded roll pin that retains the throttle stop lug,now,if this lug is against the screw and i twist the pull-shut cable could it be the roll pin is being compessed a fraction allowing slides to drop a tad? probably not just a thought tho
10
« on: December 17, 2017, 10:39:26 PM »
well no3 has acted the same way with new coils,caps,plugs and now points so boyer must have been ok after all? am toying with fitting the electronic ignition plate from DS,anyone tried it?
11
« on: December 16, 2017, 09:34:34 PM »
it is yes i replaced the standard pull-out choke with a chrome slider and all is good,the adjustment screw for the fast idle/choke is set to tick over at 3000rpm with full choke.wheather choke is on or off or even when engine is warm it`ll cut out if i twist throttle fully shut.the travel is only a few degrees too.im wondering if the pull or push set up was disturbed causing this?
12
« on: December 15, 2017, 09:37:51 PM »
I stripped the carb bank early this year and followed to a tee the pdf instructions for the pd46a carbs,at first it looked a daunting task being my first time but read first before anything and as usual i like to understand how things actually work and why.did everything methodically step by step and when it got to no 3 i decided it ws easier to tap out the pin on the throttle stop rather than mess with the throttle actuator! so after thorough cleaning and removing pilot jet using twist/pull i got everything clean.the fuel rail tube seals snapped trying to remove one of them and them each one thereafter.i bought this o-ring set from halfords (i`ll need to take a pic) they worked a treat,perfect fit and also the smaller ones are exact diameter for the mixture screws too!.built the lt back up and refitted the throttle stop in exact place i removed it from.bench synronized using thin metric rule from top of slides and each one appeared to lift the same,got them fitted and bike ran fine,started first time each time but to date if when its ticking over,i try to twist throttle further in the off position,engine will cut out! each slide lifts and closes the same and when the throttle is closed against the throttle stop screw there still appears to be enough movement to shut off engine.ive tried using a microscope to see if the slides are moving further down but cant detect they are yet must be as nothing else could surely move? the throttle actuator does move,yes but not a slide.the carbs have still to be balanced but dont think this could cause this? should the actuator hit a bump stop as it looks like it could if it were to travel far enough ?any ideas from anyone welcome thanks
13
« on: December 15, 2017, 09:11:02 PM »
"Deltarider" ye i started with points gap,i usually set it with a 14 thou sliding fit but where a 16 could not enter.1/4 points is oem it has 1/4 stamped on it but 2/3 points do not so think they could be aftermerket,i know i had to file a mm off the heel as it was way outside the gap range and opening too early. " Bryan j" i actually didnt take into account the gap might change i took it gap would stay the same.i actually bought these annoying feelers that give both imperial/metric and theres like a hundred you`ll never use lol im old school and prefer single imperial as in thou as opposed to metric.had it running today and it was acceptable apart from no3 backfire.im gonna order plugs without the "r" and see how that goes.also toying with the idea of running a second earth wire straight to engine as original runs to a bracket that mounts to the frame,the same bracket that holds the rear brake switch.peace of mind really.
14
« on: December 14, 2017, 09:17:47 PM »
Hi just an update,i checked the wiring and all seems ok,i checked the valve clearances and found 3 needing adjusted,no3 inlet had no clearance.instead of using a light for the timing i switched ignition on and slowly cranked until spark at the plug on no4 with plug against the head,both 1/4 2/3 were advanced by around 5 degree and no more room for adjustment so i took a dremmel buff and enlarged the the 3 slots in back plate.bike starts and runs very well except no3 which tends to now backfire as if reigniting unburned fuel in the exhaust but its ticking over and running.still to balance carbs tho so that might help and only set mixture screws at 1.5 turns out so im getting somewhere at last with the points set up! so cheers again for all your help/advice guys.i have one other niggling problem that i`ll put in a new post and see if anyone has any clues
15
« on: December 13, 2017, 01:09:13 PM »
Cheers K2-K6 im on my way up to the garage the now with renewed hope,i`ll strip wires and check for breaks/corosion as hairygit was saying,realign timing,if no joy i`ll swap wires on route to the coil and see if it fires up.i also wanna remove no4 plug and use a long screwdriver to determine when piston is at tdc and check timing plate to see if they match up as they should do.i`ll check the color of the spark at each plug too.maybe even worth trying old coils too.i`ll report back later with my findings and once again thanks for all your ongoing help
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