OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Four Stroke Lawn Mower Frames New member mower questions for restoration

Hi folks.
A brand new member here with some questions about a mower.

This Masport mower came to me from a recently deceased friend. I would like to return her to glory, and was wondering about a few things to do with her.

At present she doesn't start, but has compression and the fuel is not fouled with water/oil but it is at least 5 years since it ran. Oil is low but within range and the throttle knob appears to be connected.

Let's start with some identification, and for that I have photos- hopefully attached to this post.






The code on the cowling reads:
110908 0336-01 76031004

So the questions:
- What is it?
- Is it worth the restoration (other than for sentimental reasons)?
- What type of ignition do I have?
- Are parts readily available?
- Can you buy sticker kits?

Thanks,

Julian

Hi Julian, the engine is an 11 cubic inch (about 184 cc) side valve Briggs and Stratton engine of the first design generation, with a vertical crankshaft, a Pulsa-Jet carburetor, and a vertical-pull starter. I can't tell you when it was made because I think there is an error in the Code you posted (the last block of numbers). Without the correct Code I also can't tell you what kind of ignition it has.

Here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6lnsHVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msowGK-K_ny7tH217FzoPu.pdf

Engines of that generation are sometimes overhauled if they do not need much in the way of new parts. They are not valuable, overhauled or not, and only someone with a sentimental attachment to one would spend a lot of time or money on it. Nevertheless it is often possible to get them running well for very little cost, and they can be very satisfactory mower engines.

Okay I did make a mistake, since corrected in the original post.

110908 0336-01 76031004

Yep, I would have dated it as an early-mid 1970's 'Premier 4', about the last of Masport's steel catcher models.

The engine was made on 10th March 1976 then, which is at the latter end of that range, so I'd say it's original to the mower. To add to grumpy's info, it has mechanical contact point ignition.

A 1972 TV ad for the 2-stroke version:
[video][/video]

It looks very sad cosmetically, and that might not be too hard to rectify with a wire brush, some primer and paint.

I might tear it down tomorrow and see if I can get it running, particularly with regard to ignition as I think it is operating sans spark!

Are the stickers still available?

Julian

Hi mate, good luck with your resto...

I have a coupla of these in my lot in various conditions, so if you are after some chassis parts, I may be able to help!!

Thanks for the offer.

I pulled it apart this evening, and will do a basic clean up with a bit of spray paint to make it look respectable.

I separated the carb from the tank, and there is a little pin left over which I can't make out where it came from.
Is there an exploded diagram of my carb available somewhere?

Julian

That sounds as if your Pulsa-Jet carburetor had been fitted with a service fix to overcome the effects of a bowed carburetor body or fuel tank top, which unless dealt with, causes extremely rich mixture in that model of carburetor. It would have been a small roll pin dropped into a hole in the fuel tank top right near the center. It would have had a small transparent Teflon washer around it, maybe about 6 mm diameter - difficult to see, and if lost, impossible to find. The purpose of the roll pin was to hold the washer in place. If you can't find the transparent Teflon washer, the roll pin is no use to you.

The Briggs part number for the kit is 391413. They are commonly sold in ten-packs. Here is a picture of what they look like:
http://www.equipatron.com/briggs-stratton-4184-10-to-pack-of-391413-overhaul-kit.html

I suggest you check whether the tank top or carburetor bottom is bowed a couple of thousandths of an inch in the center.

Grumpy, my hat off to you. That shows some knowledge of this engine.

I was meticulous about extraction and parts retention.
There was no washer.
I discovered where it went by trial and error and have it back together.

Now the damned trigger wire has broken off clean at the point at which it meets the body of the coil! I am so keen to get this running but I fear that I will not be able to source a new coil.
Any tips on where to get one?

Fixed the break.

I have spark, and thus the transistor ignition I added must be firing. I can smell fuel coming out of the exhaust.

It will not go though.

I am ready to put it on the street.

Do you mean the high tension wire? That is a part of the "Armature - Coil", Item 333 in your Illustrated Parts List, and Part Number 298502. You can easily buy a new one, from the Outdoorking online store or on ebay. It is the same part used on all of the horizontal crankshaft and vertical crankshaft 3, 3.5 and 4 hp Briggs engines made prior to 1982. Alternatively, you can fit a Magnetron electronic ignition unit from one of those same engines made from 1982 onwards, and you then just cut the wire running to the breaker points and condenser inside the flywheel. The cheapest way to proceed is to open a thread in the Outdoorking Wanted forum, asking for a coil or Magnetron ignition module for your engine. Most likely someone will reply saying they have a second-hand part available. They will then send you a Private Message regarding price, postage cost etc.

In other words this is not a big setback, but it will cost you a few dollars, especially if you want to fit a new genuine coil the same as your old one. Most of us prefer the second-hand Magnetron solution unless the engine is a collector's item. The Magnetron units have a very good reputation for reliability, and they get the whole breaker points and condenser scene out of your life. When engines such as yours get very old they sometimes wear out the tiny plunger that operates the points, in a little compartment inside the flywheel. That lets oil into the compartment, and it eventually stops the ignition unless you fit a new plunger.

OK, I won't ask about your high tension wire repair in case I don't think it will last. It sounds as if you had already fitted a Magnetron ignition unit.

If your spark plug is wet, despite having spark, your mixture is probably very rich. Do you remember when I told you that with your model of carburetor, if you have a bowed tank-top, and you put it together without the little teflon washer, it will be extremely rich? And you couldn't find the invisible washer, so you denied there was ever one in there, despite there being a pin that was only there to hold the washer in position? Do you see a pattern forming in all this?

Unless someone had fitted the 391413 kit, then later found it wasn't needed and just left the roll pin in place without the washer (a very unlikely chain of events, in my opinion) your engine has a bowed fuel tank top or carburetor bottom, and is flooding because it no longer has a teflon washer, because you lost it. If it makes you feel any better, the only time I ever took apart an engine that had the kit in it, I lost the washer too, and the engine flooded when I put it back together. I do not like that kit, so I draw-filed the top of the fuel tank flat, and it worked perfectly ever afterwards.

Sounds like it was the primary wire [or primary earth wire] that broke. Not that uncommon back in the day, as these are single strand wires, and won't take a lot of flexing. Often they break flush with the edge of the coil too, which makes repair difficult, or sometimes impossible.

JulianB, did you fit a complete late model Magnetron coil [as grumpy refers to], or just an aftermarket electronic trigger module?

Here's a diagram of the carby pin and washer in the right position, from the Briggs Service Manual for that model:


And here's the critical part of the tank top that has to be checked for flatness, shown as the shaded bits in the close-up:


If the feeler gauge will fit under the straightedge, the tank is out of spec. It usually can be repaired as grumpy describes.

Hi folks.

Yeah, grumpy I went back over my dismantling bench with a fine toothed eye and didn't find it- probably lost due to uncharacteristic carelessness! My bench is a well lit rubber mat for such projects, so usually nothing escapes .

There are two small wires and a high tension wire running from the coil. High tension is not an issue. One of the other small wires was earthed to one of the bolts holding coil in place, this remains undamaged.

It is the wire that leads up under the flywheel that was damaged. This I have repaired and is now connected to an aftermarket solid-state ignition unit. I have spark at the plug, which is clean.

I will dismantle the carburettor again, and see if the washer remains in situ.

Even if it was rich you think I'd have even a smoky-stuttering attempt at running. Not so.

It is hot here today so it might be a job for the morrow.

In anticipation of finding I have a warped casing and need a washer, where do I source such an insanely small part?

JulianB, I noticed the resemblance of your Masport with one of previous projects. If you are restoring it then keep in mind that it may have originally come with a top cover like mine in the photos. Note the Higher than usual carby/air filter bolt. regards.

Christo, I don't think that JulianB's mower would have had that cover, due to its cowl-mounted throttle control.
Every old Masport I've seen with that throttle setup, just uses the engine cowl as the top cover.

Errggh. That's the curly question. The 391413 repair kits are readily available in the US, but generally only under B&S P/No 4184, which is a 'workshop pack' of 10 sets. Not that dear [can be got for <US$8], but postage will cost more than the parts! jackssmallengines.com is one US parts mob who will accept international orders, but it's necessary to go right through their checkout process to see the postage cost.

Have you redone that flatness check, with the feeler gauge, as in the above diagram? That will tell us if the washer is actually required here, although it looks like it is.

If you're accustomed to using hand tools, grumpy's method of draw filing the tank top back to flat is worth considering. We can find an online technique how-to, if needed, I'm sure.

All you need is a way of holding the tank; something like a 'B&D Workmate' [or clone] portable bench/vise setup works quite well, if you don't have a decent sized bench vise [with soft jaw covers]; and a good sized [250-300mm] fairly fine single cut flat file. And a wire brush, to clean the file teeth.

Yes Gadge you are correct. I posted the wrong picture. This is the one that I meant to post. Hope it helps him. regards Chris.

You can get a basic outline of draw-filing here:
http://armyordnance.tpub.com/Od16218/Od162180135.htm

The subject of draw-filing Briggs fuel tank tops comes up in these threads:

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=22526#Post22526

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=46083#Post46083

You might also have a look at this ebay item:
http://www.ebay.com.au/itm/OEM-Brig..._Power_Equipment&hash=item3397d5be6f

Unlike some of the sellers, at least he knows there are supposed to be washers in the kit, and he states that some are actually still present in what he is selling. Again unlike some of the sellers, his postage charge seems reasonable.

If I at least had an idea that it worked I might go about draw filing, but the damned thing won't start- even in a likely rich running state!

I notice that the starter is missing a few teeth so i had better be careful...