Marquis 4A clutch
Morning, nearly the weekend. I need to remove clutch assembly to get access to land rolls and am a tad stuck. I managed to make a simple pin spanner that has loosened nut to enable chain adjustment and removed chain but am uncertain on my next move. Do I carry on undoing the nut until it’s undone or undo 3 spring bolts which looks like an accident waiting to happen? I can’t find a service manual although have found engine and operating instructions.
Piccie to aid what I’m talking about. Thanks Nick
You are ok undoing the internal collar with the peg spanner . The three nuts are safe to undo , by the time that they get to the end of their threads the springs are almost decompressed. The roller sprocket is screwed onto the shaft - left hand thread and can be an absolute barsteward to get off . I’ve made tools to hold both the sprocket and engage the slot in the other end of the shaft. If the rollers are seized to the shaft I leave the whole assembly submerged in a drum of diesel for a week before trying to free them. More homemade tools. Don’t be tempted to try turning the rolls with a bar poked into the lube holes. Cast iron does not tolerate that treatment.
Tomorrow I’ll put together some images on roller dismantling.
Much appreciated. What about an old biker trick of getting a blowlamp on the sprocket. Not so much heat as to start bluing the steel - and spoil the temper of the carbon steel of course. Good to know about the LH thread
I got caught out on that with the rear offside wheel of a VW beetle hmm
By all means use heat . I usually try purely mechanical means first - avoids workshop conflagrations and hot sprocket juggling !
Thanks Wristpin I’ll see how I get on, those tools look pretty substantial, as does the cradle.
Thanks Wristpin I’ll see how I get on, those tools look pretty substantial, as does the cradle.
Crude but effective!
I should add that the not uncommon seizure of rear rollers results from the lack of correct lubrication. Ransomes recommend the use of SAE 30 or 40 oil for all the lubrication points including those accessed via the holes in the rear rollers. If grease is used there is a tendency for it not to penetrate the fairly close tolerance between roller and shaft and to then dry out in the oilway.
Not crude at all, if they do the job. I’m sure mine will be worse. I have taken on board info re: oil thank you and it does say oil in all instructions I have read. The rollers seem to have something loose rattling around inside which could be a bit of a downer but time will tell. I presume that this is the slot to hold roller spindle when undoing sprocket having taken out the oil nipple. If I make the bolted in spindle holding version does the side frame need supporting to prevent movement of and thus hindering insertion of bolts?
Just thought that I’ll have to work out PCD to do bolt in version.
Before you set about the rear roller, just make sure that the rattle is not the drive pawls working correctly!!
Support the machine so that the rollers are clear of the ground and then turn each one in the forward direction - they should run freely without turning the shaft and sprocket. If they try to turn the shaft they are seized or partially seized to the shaft.
If they run freely as above, then turn them in the opposite direction and they should lock and try to turn the shaft and sprocket.
When I made my shaft holding tool I had the advantage of having a spare shaft bearing holder to use as a template but if you remove all the hex head screws and press a bit of paper over the access orifice and the screw holes you will have an accurate enough template. If you drill the hole for the screws slightly oversize you won't have to "fight" to align them in use.
If you have the luxury of an assistant you may be able to do without a fixed shaft holding tool but as I'm usually working alone it makes life easier.
Sprocket removal is easier if you can get the machine to bench height and tip it back so that the handle bars are touching the bench to give good reaction against the considerable force that may be needed to shift the sprocket in a clockwise direction.
Thank you, lifting it out of the car was enough for me and bench needs cleaning
I was able to get my Marqui into my hatchback with handles removed. That was quite easy
As the seller rightly noted it will be difficult to get it out again.
It weighed 65kg
It took 2 hours of single handed sweat with a hoist and tirfor and scaffold planks to extract it safely without damage. Wont do that again.
Morning, I removed valve cover on Marquis to find this exhaust valve spring a bit off kilter. I’ve checked clearance and I’m getting .011in. which is a bit big but haven’t decoked and lapped yet. Has anyone an idea of cause of spring sitting skew-whiff?
There were two different valve spring retainers used, a pin through a hole in the valve stem or a horseshoe clip that sits in a groove in the stem. I’m guessing that you have the pin type and it’s possible that whoever last assembled the exhaust valve didn’t get the pin centred in the retainer, but I’m surprised that it hasn’t either sorted itself out or worked its way out altogether.
Clearances. 6 thou on both. More important that they are 6 thou minimum than worrying about them being a bit too wide. If, after lapping etc , you end up between 6 and 10 , you are unlikely to see any adverse effect ; the Sloper is a fairly tolerant engine.
My exhaust valve spring looked similar, better when refitted but still not as straight as the inlet. Horse shoe clips on mine.
Thankyou for replies. Mine does have the pegs. Spring free length only shrunk by 1mm. The holes in the cups are quite large so there is a lot of movement around the valve guide but both inlet and exhaust are the same diameter.
Next problem. Are the terminals on points supposed to be soldered on and how is HT lead removed and replaced.
Changing the HT lead is made easier if the stator plate carrying the coil etc is removed, but FIRST scribe around the washers under the two fixing screws or make some other witness marks to enable you to refit it in the original position. With the stator off the engine maneuver the lead so that it is in line with its housing, then while twisting it anti clockwise pull on it GENTLY. In the bottom of the housing is an "inverted wood screw" , so when fitting the new lead, push it in as far as it will go and while maintaining pressure on it, twist it clockwise until it bottoms.
Soldered connections. Usually found if the points and condenser are the originals; replacement points often have a small screw and nut to clamp the LT and condenser wires. I usually do away with the points and condenser and fit a Meco solid state trigger unit which avoids ever having to go into the mag to deal with dirty/corroded or worn points.
It may be an optical illusion in your image but that points gap looks HUGE;should be 18thou, I think . The correct setting is usually found cast into the face of the flywheel.
That’s very helpful re:- HT lead. I’ve looked for meco ignition but central are the only ones who come up on search and they’ve been out of stock for ages, might try ones on auction site.
I did double check points gap but I’d used zoom when taking picture and am getting a spark when flicking over with pulley.
Should I use hylomar on head gasket when reassembling.
Carb and head have come up quite well after putting in ultrasonic cleaner
I don't think you need sealant. If you are using a good new gasket and surfaces are super clean and flat.
Per advice from Wrispin I went over the head on a surface plate - towards the bottom of the 1st page on this thread -> https://www.oldlawnmowerclub.co.uk/forum/history-and-technical/technica…
Head bolts torqued up to spec, not had any issues.
Hope your valve cover fares better than mine..
Thanks for reply Chris I have used your epic rebuild thread several times for reference while dismantling mine. I’m trying to find something flat to use as a surface plate. I’ve ordered a torque wrench for the job.
The valve chest cover looks like a pain as there’s not a lot of mating surface on the top radius’s. I might use liquid gasket as I have recently had,to replace timing chain on car and have some leftover to see if that works. I see you’ve made a new snazzy one so know where to send my order if I can’t seal it.
My valve cover had sealant on it originally and I think its an absolutely fine thing to do if done sparingly. Think mine was done with a 4" paintbrush tho...
It was in a very bad way, hopefully you will be fine with yours if you flat plate it first.
Hi I have a 1/4” brush which should be better. Is the reason for marking screws on stator plate to preserve the air gap between flywheel and coil?
I have found these numbers etched on flywheel rim, which not being an expert in anything let alone ancient runes, I can’t decipher, any offers?
Here’s piccie of flywheel etching as can’t edit things still
Not been there myself yet Nick so would not know, do you have the F15 repair manual? If not, I have a copy supplied by Wrispin.
Hopefully the mower Techs will chip in on that question.
Hi, is this the manual you have? Mine’s for a F12. The one I have says on reassembling engine fit magneto cam but don’t tighten bolts of stator till timing checked? You’ve got the electronic points in yours haven’t you so suppose there’s no need, although you sort of have with your punch. My flywheel puller’s a bit more basic than the one you made.
Yes mine is for F12 also, not come across anything not described in it yet for my F15 but have not had the flywheel off which I may have to do out of curiosity. The F12 manual des not mention anything about those numbers on the flywheel?
I've got an F15 workshop, parts & user manuals on thier way, no idea what derivative of F15 they will be for yet, if you need copies give me a ping.
Hi Chris, I think you should be able to see etchings if they are there just by removing the cowling as it’s on the outer rim, or maybe you would have noticed when you cleaned up for repainting. May well ping you re manuals thanks.
I think I’ve got a bit carried away and stripped engine down for cleaning and inspection. The question I have is which way do the oilways on the thrust washers face? I ask this because the illustration in the parts manual (item no. 97in diagram) seems to show it facing the opposite direction to the way they were facing. Should the oilways face outwards or face each other. I could make an uneducated guess but thought asking first would be a better bet. Hopefully pictures attached as have had a problem uploading them earlier.
Also does the spring for the gear trough come off its boss easily.
Thrust washer. The gaps go against the moving face of the crank
The trough usually lifts off the spring easily but the other end needs to be twisted against the direction of the spiral of its coils to release it - I think, it’s along time since I’ve removed one.
Thankyou Angus, the thrust washers were fitted facing the way you say and the spring’s off too, you must have a good memory.
I’ve picked up a “spare/donor” machine but the Amal carb air filter is not the oil soaked gauze variety. It appears to me that these were predominantly used on motorbikes. My question is are these filters going to be ok because they only have a fine gauze sandwiched between two others and doesn’t seem as efficient at providing adequate filtration. Is it worth trying to source the parts to build the ‘correct’ filter or not.
In real life terms for normal lawn mowing it’s probably not going to make too much difference. Not as if you are mowing cricket wickets at soil level and creating a dust cloud. A discarded pair of tights may add some additional protection but not sure what denier to recommend!
Seeing as you seem to have the correct carb/airfilter, I would use that.
Thankyou Wristpin and Hortimech for helpful replies, decisions decisions. Used to be indecisive now I’m not sure.
Does anyone have any experience replacing the filter gauze in the ewarts fuel tap please. Mine’s ripped and having looked on u tube they seem to be soldered or pressed in versions. I’ve applied heat to see if they’re soldered but nothing happened so assume have to drill out old fitting. Villiers parts only have stainless ones and they say to cement in with jb weld or similar. Any offers on how to preserve the bore while cement applied greatly appreciated.
I have no idea, but would appreciate a few images out of interest on the setup - and potentially help
Thanks Chris, I’ve sourced some brass gauze and hopefully will be able to solder into tap with the bore blocked off and then seal the open end of the gauze.
On ,another matter I’ve got my interim Marquis running and tried it out today. It was a sorry affair. It turned into a lesson in using ungoverned cylinder mowers , jogging and wood turning in one go. The grass I had to cut is a bit rough and long and I thought I’d remove the cut height adjuster stop to raise the blade that little bit extra. However, the front rolls just tucked under themselves and came into contact with the cylinder, oops. On refitting the stop and removing the two middle rolls the first attempt went better but it was a lot of fun
Now you know what the stop was for; all knowledge has its price!
I like the character of the ungoverned engine, keeps you on your toes especially in smaller spaces. Good fun.
Hope it made you chuckle Angus, maybe have to plant a tree to replace new rollers required.
Chris I must admit that I had to ride the clutch a bit at times to coordinate everything.
Thinking about it you could say “a funny thing happened on the way to the forum”