Tinhat warrior trademark.

[Niels AbildgaardParticipant @nielsabildgaard33719]

The two pictures shown are from a small (36mm bore two stroke engine) found on our metal recycling center.

They look very well enginered ,but my living dream is to demonstrate that a sidevalve two stroke will be better than the +50 million Briggs & Stratton type engines sitting in lawnmovers golf carts etc everywhere:

The parts from scrap photo do not need a lot of modification to show rest of humanity the true engine way.

On the crankcase casting there is a small picture of a mans head with tin hat.

Do some here know name of company?

**LINK**

Do some here know what name engine?

[Niels AbildgaardParticipant @nielsabildgaard33719]

A scrapyard find.

[Neil WyattModerator @neilwyatt]

Perhaps related to one of these:

http://www.weldmart.com/main/centurion_intro.html

Neil

[Jeff DaymanParticipant @jeffdayman43397]

Hi Niels, I think that is a Poulan leaf blower engine. The 012487 and 012481 part numbers on the crankcase and cylinder are Poulan numbers.

Just a note on the quality of Poulan engines – these engines are not a model of best practices in small engine design. They are low cost throwaway consumer grade engines. They last a few hours doing a great job and then they are worn out, either in the bore, or the connecting rod ends have huge wear.

Taken many apart over the years, only to find the above problems. But since you can get a replacement chainsaw or leaf blower with a new engine from many hardware stores here for about $150.00, no one fixes them, and parts are hard to find anyway.

[Dave HalfordParticipant @davehalford22513]

looks like a 2005 casting mark so not too shabby on lifespan

[Jeff DaymanParticipant @jeffdayman43397]

Hi Niels – here's a parts diagram for the engine I think it is.

Dave – many saws and leafblowers only get used a few hours a year, so it can take many years to get to the end of a 50 hour engine lifespan. For many consumers this is just fine, and was what the machine was intended for. I'd be happy with a cheap saw or blower that lasted 14 years!

[Niels AbildgaardParticipant @nielsabildgaard33719]

Hello Jeff and thank You for guiding.

I have never seen such engines before but found a chineese supplier after reading Your mail.

 

**LINK**

 

The engine I want to build is shown here

 

http://[img]https://i.imgur.com/sOCfRuu.jpg%5B/img%5D

 

Where did You find the parts cataloque?

Edited By Niels Abildgaard on 31/01/2019 15:39:50

[Jeff DaymanParticipant @jeffdayman43397]

Hi Niels, The diagram was from a small engine parts place in the US called Jack's small engines, as I recall. I was looking into fixing a leaf blower of this kind in the summer, and looked it up.

Could be that some or all of the parts for these engines came from Taiwan or PRC to Poulan and Homelite etc. originally.

I could not see anything at the imgur link you sent, just FYI.

Good luck with your project.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jeff Dayman on 31/01/2019 16:21:40:

I could not see anything at the imgur link you sent, just FYI.

.

Try this, Jeff: **LINK**

https://i.imgur.com/sOCfRuu.jpg%5B/img

MichaelG.

[Niels AbildgaardParticipant @nielsabildgaard33719]

That lin-king-thing is difficult.

It is safer to use the album here at site

 

Edited By Niels Abildgaard on 31/01/2019 18:16:21

[Nick HulmeParticipant @nickhulme30114]

Pushing that rock up the hill again Sisyphus? 😀

[HopperParticipant @hopper]

How is that design going to be better than a Briggs and Stratton type four-stroke? What's the advantage? And will the inherent overheating and warping of the side-valve combustion chamber and exhaust valve/seat be exacerbated in an engine that fires every single stroke, with no "cool down" intake stroke in between? (Us old Harley-Davidson side valve performance tinkerers think about such things!)

[Niels AbildgaardParticipant @nielsabildgaard33719]

Posted by Nick Hulme on 01/02/2019 00:21:52:

Pushing that rock up the hill again Sisyphus? 😀

 

It hard work that someone has to do.

More engineering than modelmaking so it is OK.

Edited By Niels Abildgaard on 01/02/2019 08:35:31

[Niels AbildgaardParticipant @nielsabildgaard33719]

Posted by Hopper on 01/02/2019 07:37:30:

How is that design going to be better than a Briggs and Stratton type four-stroke? What's the advantage? And will the inherent overheating and warping of the side-valve combustion chamber and exhaust valve/seat be exacerbated in an engine that fires every single stroke, with no "cool down" intake stroke in between? (Us old Harley-Davidson side valve performance tinkerers think about such things!)

A more MC friendly version.

Two stroke exhaust is not so hot as from a fourstroke.

The piston and cylinder stays rounder than conventional two strokes.

If 1% oil mix is enough it polutes less than a B&S type SV.

Fewer parts

[HopperParticipant @hopper]

Posted by Niels Abildgaard on 01/02/2019 08:43:20:

Posted by Hopper on 01/02/2019 07:37:30:

How is that design going to be better than a Briggs and Stratton type four-stroke? What's the advantage? And will the inherent overheating and warping of the side-valve combustion chamber and exhaust valve/seat be exacerbated in an engine that fires every single stroke, with no "cool down" intake stroke in between? (Us old Harley-Davidson side valve performance tinkerers think about such things!)

A more MC friendly version.

Two stroke exhaust is not so hot as from a fourstroke.

The piston and cylinder stays rounder than conventional two strokes.

If 1% oil mix is enough it polutes less than a B&S type SV.

Fewer parts

How is two stroke exhaust cooler than four stroke, from combustion of the same fuel under same compression?

How does cylinder stay rounder than a two-stroke? Side valves are notorious for distorting the cylinder due to asymetrical combustion chamber shape where the valves sit. So much so that Harley-Davidson used to run their sidevalve race engines for an hour or two then rebore the cylinder to get it back to round before racing it.

1 per cent oil mix in a two-stroke bottom end and cylinder? That sounds pretty radical. Is it possible with synthetic oils?

[Ex contributorParticipant @mgnbuk]

1 per cent oil mix in a two-stroke bottom end and cylinder? That sounds pretty radical. Is it possible with synthetic oils?

MZ had engines reliably running at 100:1 on synthetic oils before they suffered from German reunification. They were looking for ways to reduce emissions as regulations tightened, but didn't formally adopt the leaner pre-mix as it was felt that accurately administering the smaller quantities of oil was likely to be problematic in the real world. The adoption of Mikuni dosing pumps on export bikes reduced emissions compared to premix bikes – the effective ratio on the pumps was around 32:1 at full throttle, but leaned off to around 70:1 a low speeds/ throttle openings, compared to 50:1 on premix versions. My wife always hangs back if she is following me on a premix MZ after prolonged town running, as the over-lubrication puddles in the crankcase & clears (smokily – for a couple of hundred yards) when accelerating when the restrictions clear. No visible smoke at higher speeds with modern oils, though.

Nigel B (two stroke fan since 1976)

[HopperParticipant @hopper]

LOL, we won't mention "stink wheel" then. Come a long way since I first threw a leg over a BSA Bantam two-stroker. I was always in awe of those guys who got Bantams to do 100mph or close to back in the day and always had plans to imitate them, which never got much further than rubbing the cylinder head on the concrete garage floor until about 1mm was removed…

[Ex contributorParticipant @mgnbuk]

Come a long way since I first threw a leg over a BSA Bantam two-stroker.

BSA Bantams are mirror image MZs – with the quality engineered out !

The second most produced motorcycle engine of all time, the DKW RT125. Given as war reparations to BSA (who didn't really want it !) & Harley Davidson & widely copied by many others (including the first Yamahas). The DKW factory was dismantled lock, stock & barrel & taken to the USSR as part of reparations, where the RT125s designer – Hermann Weber – died in a Russian labour camp after the war.

Nigel B

[Clive HartlandParticipant @clivehartland94829]

I seem to remember that my Briggs and Startton engine on my garden cultivator boasted that it had an alu. piston running in an Alu. bore. It seemed OK and did a lot of hard work in my Garden plot.

Most of these engines are die cast built to quite wide tolerances. It was the bits attached to it that fell off or cracked.

Clive

[Neil WyattModerator @neilwyatt]

My brother used to have an MZ. Every other biker he met said 'does the job'.

My first pillion ride was on an MZ (running on paraffin) with a spare rear wheel somehow perched between me and 'Spam' who was steering the thing…

Neil.

[Niels AbildgaardParticipant @nielsabildgaard33719]

There is only one real MC and I am their prophet.

80000 km on two sparkplugs and still very fit when I got too old.

Son on picture sells ships diesels in North Atlantic area today..

[Ex contributorParticipant @mgnbuk]

I prefer the TS250s to the ETZs (250 or 251) – less peaky power delivery & more economical, but the disadvantages of 6v electrics and drum brakes. I had one of the last DDR-era produced ETZ251s, (in a fetching shade of beige) rescued from my brother-in-law, who had bought it new but then lost interest & left it festering in a damp garage. Build quality had rather gone down hill by the end of the DDR, though. Didn't keep it long, though did do a round trip to the Ace Cafe for the first "Red October" East European bike day on it – near 400 miles in the day & a long way to go for an expensive, indifferent burger !

My late friend Mark Dicker was Classics Officer for the MZ Riders Club & he reckoned that the ETZs would disappear before the earlier bikes due to frame corrosion – the area of the frame that the footrest bar bolts to rots off. The frame is used as part of the inlet air system & heavier dust accumulates at the bottom of the frame – this gets & stays damp, causing the frame to corrode from inside. The TSs used a similar intake system, but the tubular frames were heavier gauge than the sheet steel box section on the ETZs, so they last better + the tube is blanked off with an easily removed plastic plug that enables the dust to be cleaned out. The ETZs have (IIRC – it has been a while) a welded on closure with a small, easily blocked, drain hole. May be worth checking this area on your tidy bike ?

I have 6 in various states of assembly & function – 3 off TS250/1, and ES250/2, an ES150/1 and an ETS250 G5 ISDT Replica , of which only the oldest TS250/1 (which I have owned for 29 years) is running. So many projects – so little time !

Nigel B

[Niels AbildgaardParticipant @nielsabildgaard33719]

Hello Nigel

I have given away worlds best turning Boxford to a friend ,thrown a lousy Boxford out and given two chinese lathes,WM280 and a WM210 away and mistreat a WM250 for the moment.

Next time I fall in love with another lathe I think we make swap .A Lathe for a MZ?

That dirt collection problem in ETZ frame is new to me and I sold it many years ago.

It reminds me of my four Austin Maxis that all died from rust due to dirt in the front transverse bridge.

Front wheel threw mud into a corner.

[SamsarandaParticipant @samsaranda]

Not all two strokes from the 60’s era had to be smoke generators, I had an Ariel Leader 250 two stroke in that era which I ran on Filtrate colloidal graphite as the lubicrant in the fuel, I can’t remember the exact ratio of lubricant to fuel but seem to remember it was 100/1, the exhaust was clean with only a trace of blue smoke. Ah those were the days.

Dave W

[SamsarandaParticipant @samsaranda]

Not all two strokes from the 60’s era had to be smoke generators, I had an Ariel Leader 250 two stroke in that era which I ran on Filtrate colloidal graphite as the lubicrant in the fuel, I can’t remember the exact ratio of lubricant to fuel but seem to remember it was 100/1, the exhaust was clean with only a trace of blue smoke. Ah those were the days.

Dave W

Edited By Samsaranda on 01/02/2019 19:35:01

Edited By Samsaranda on 01/02/2019 19:35:15

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