OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines B&S 3HP - M#80202

Hi All,

I've recently acquired a Rover Thoroughbred 16" mower. I'm going to restore this (first time).

the motor on it is a B&S 80202. It's a 1975 build. I'm curious as to how available parts are and whether they're still made? As much as I could easily just bolt on a new honda and be on my way, I'd like my hand at restoring the motor also.

The pulled the motor off tonight and started stripping it down. The choke and accelerator springs have gone and will need replacements, however, if I can buy a new carby complete it might be easier to deal with knowing I won't have to fuss about anything else.

The also pulled the tank off and emptied the fuel out which was a lovely shade of red no thanks to the rust in the tank. It doesn't look too bad, so I'm hoping I could possibly de-rust the tank, but once again, are these still available at all? The rubber grommets for the breather are not much chop and are rather hard, so they'll need doing.

The pull-cord starter assembly I believe is rat Poo. The cable can be pulled, but doesn't retract and at times slips when pulled. Not sure if these are fixable, or are a replaceable part. I have the complete parts manual for the motor, but the part numbers don't mean much to me if they're not available nowadays.


I've attached some pictures for reference.

Many thanks in advance

G'day & welcome, yes to parts either from here or overseas.

Oh I forgot to ask - Where are the best locations to buy parts for these? Local mower shop, or is there a go to location?

Ebay has a few good sellers that are mower shops selling on there. Google is your best friend when looking for parts.
sent you a PM..

Hi Paul, thanks for the info. I'll give ebay a look over

G'day Chris86,
Before you tear it down any further than as shown in the pics, do a basic compression check. Spin the flywheel backwards, and see if it bounces back off compression.

Parts availability for these small side-valve Briggs engines is generally good, as they didn't change much over ~30 years.

However, it can be pretty annoying to have one that has had minor external parts ratted off it, as some of these parts are priced a bit extortionately.

And you may get a shock if you price a new Honda, good though they are. The current Briggs 'sloper' engines are nearly as good, and a lot cheaper.

Keep in mind that it would be very easy to over-capitalise this machine, given its rarity. Even common wear parts like drive sprockets are not likely to be available.

Also the pull starter is fully serviceable & easy to repair.

I have a couple of these engines (stand alone) with various carby/tank set ups

Hi Gadge,

Yeah it certainly has good compression. The bloke I grabbed it off said it was running and continues to run although difficult to start due to issues he suspected were related to the carby, but given it's poor maintenance, I dare say there was more to it than that. With that said, compression appears to be great. Parts appear to be rather cheap and I can completely understand the reasoning behind over-capitalizing (I was originally going to replace the motor), but at the same time, a huge part of me isn't concerned about the cost more so than I am the learning experience by doing this. By the sounds of the information you have provided along with others, it's obvious it's likely to be cheaper in the long run to buy a new motor, but having never having done this to a motor before, the cost of learning is cheap.....at least that's my reasoning, as twisted as it may sound.

EDIT: The engine had less than 100mm of oil in it - dirty at that. I believe these are alloy blocks and they don't like low or dirty oil?
Not sure what damage if any is done, or whether it's worth just pulling it apart and giving it a good clean up and rebuild from scratch?

I wish I knew this when I threw an Echo garden vac on a verge pick up one year...I had too much going on, and never gave it a second thought. I'm sure I'm not the only one guilty of such silliness over the years

LMAO, I fully relate to that reasoning Chris, by doing it, It's allowed me to help many others who wont do it or not mechanically minded..

Looking on the B&S website for my specific motor model, I can't find it. They have a 80202-0535-99, but mine is a 80202-0535-01. Unsure of the difference between the two? Assuming probably nothing as specs look the same.
According to the site, the carby is no longer available OEM.

The common parts list covers your variant anyway; this is the one you want:
http://bsintek.basco.com/MDEXResultsPages/PDFDisplayPage.aspx?fileName=Z6jmyBVJ1DajI

As to the carby, yours doesn't look butchered, so why would you need the complete assembly?

These Pulsa-Jets are a very simple carby. Unless there is excessive slop between the throttle butterfly shaft and the body, it will be easily repairable. Most of them only need a pump diaphragm and a new carby to tank gasket, along with cleaning out the tank and checking the pickup tube screen.

If the compression is OK, there's no real need to open up the crankcase. Cylinder head off to clean off deposits, and check/adjust valve tappet clearances at the same time, should be all that's needed there.

It's true that they don't take kindly to being run with low oil, but as it hasn't 'thrown a leg out of bed', so to speak, its most probably OK for further use.

Being a '75 it would hurt to check your valve clearances as when these close up can make them hard to start as you have too much compression release at start-up.

Yeah I will likely pull off the head tomorrow for a gander and check the condition of the bore also. I still haven't ruild out a complete rebuild just for the sake of it.

I've taken the head off. The bore is in beautiful condition. Piston has little carbon build up, but valves have quite excessive carbon build up.

I'm trying to get the crank case open but not sure whether I should take the magneto off first?

Managed to get the crank case open, but how do I get the flywheel off? Not sure how to get the clutch assemblyou off

Alright, I've been at it a couple of hours and having being the first time pulling one apart, I kind of did it backwards at first, but in the end I got there. Lesson's were learnt to say the least.

Anyhow, I managed to get the head off and pull the guts of her out. The carbon deposits on the valves were quite bad, and there was obviously presence of carbon on the piston. Initially the bore looked to be in great condition, and I guess in the scheme of things it is, however, after closer inspection upon removing the piston, there is scarification marks on the bore. They're not deep, but can be felt using a finger nail across the surface. The piston also doesn't look much chop. My best guess is that it was run without the filter on. It doesn't appear that the carbon deposits did the more so than grains of sand as a result of the motor being run without the filter housing on (that's how I picked it up).

The major thing I wasn't aware of is how to remove the flywheel and starting clutch assembly. I wasn't aware there are special tools for this, and I'll certainly aim to pick this up since this experience, however, with a little bit of ingenuity, I managed to remove it without damage. What occurred was that I removed the crank case housing prior to removing the clutch which made it extremely difficult to hold when trying to undo the clutch assembly. It was frustrating, but I found it quite funny in the end.

I'm an electrician, and am certainly no mechanic, but given my fault finding and problem solving skills, I managed to get through the process rather smoothly all things considered. Given how easy it is to take a part, I'm more than confident putting it back together. The timing marks are rather simple to follow also. No doubt I'll have questions upon putting it back together, as my aim in all this is to build a very smooth sounding little motor.

I have attached some photo's for you all. I'd love some input





























Moving forward, what's the best way to hone the bore to give it back a smooth surface? I'm going to try locate a new set of internals and this is where I start entering uncharted waters; it's all well and good pulling something apart and putting it back together, but doing work on the block itself has me scratching me head

Well it going to need over sizing. Now the old IPL may indicate sizes other than .020 over but usually only the .020 over is available nowadays.

As doing the honing it take a ridge hone to true up and resize the cylinder; flex and ball hones won't do it. They will only amplify any oval and/or taper of the cylinder. The cylinder appears to be aluminum only so you need stones for aluminum 180-220 grit. My Lisle 16000 uses 180 grit stones.

Truing means the removing all scoring, tapering, and oval (Egg Shape). One or more of these can be present on worn cylinder.

Now the crankshaft journal looks good from what I can see especially for an engine as old this one is.

Trying to find a shop that can bore small bore engines is getting very difficult these days, even in a big city like Melbourne they are few and far between. They have either retired, died or just given up because it just isn't economical to rebuild motors these days, cheaper to just replace