HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
sbkenn
User Rank
Gold
Re: Must Have Been A 2-Stroke!
sbkenn   7/23/2011 10:17:29 AM
NO RATINGS
On the old Guinness canal boats, used to transport the famous beverage bearing the company name, the skippers could reverse the Bollinder single cylinder diesels by closing the throttle(though throttle isn't really the right term), until the engine was almost stopped, then "blipping" the throttle at the right moment.  These engines only had a forward gear, and would run their bearings dry if left running backwards for long.

wb8nbs
User Rank
Silver
Re: Must Have Been A 2-Stroke!
wb8nbs   7/22/2011 5:04:30 PM
NO RATINGS
Four stroke diesels wil run backwards too.  It surprises the heck out of the driver and blows all the oil out of the air cleaner. DAMHIKT.

arrowpal
User Rank
Iron
Re: Must Have Been A 2-Stroke!
arrowpal   7/22/2011 1:43:00 PM
NO RATINGS
I agree, a 2-stroke. Very common issue, especially in the early days. A 2-stroke engine will run either direction. Improperly adjusted ignition timing can aggravate the reversing problem.

wayneowatts
User Rank
Iron
Re: Must Have Been A 2-Stroke!
wayneowatts   7/22/2011 1:35:06 PM
NO RATINGS
My thoughts exactly.  As a youngster in the 70's I was involved with racing small 2-stroke motorcycles and heard several stories about them suddenly going in reverse from the starting line.

 

VM
User Rank
Iron
Re: Must Have Been A 2-Stroke!
VM   7/22/2011 1:30:31 PM
NO RATINGS
I'm sure it was a 2 stroke...

Many Years ago (more than I care to think about)  A friend of mine was tweeking the ignition timing on his suzuki 250.  Advanced it a little bit, started it, cracked the throttle and dropped the clutch.  Did this a number of time - happy with the perceived increase in acceleration until he just went a little too far.

He started the bike (kick start of course) and received a nasty kick back to boot.  The bike was running through, so he goosed the throttle and dropped the clutch.  The next moment he was lying on the ground,hands cupped around a fragile and now very painful part of his anatomy.

The engine had started in reverse - need I explain further....

PhilR
User Rank
Iron
Backwards.
PhilR   7/22/2011 1:27:39 PM
NO RATINGS
It is entirely possible you are putting us on.  However...

Reed valve 2-cycle gas engines can run backwards and forwards, depending on the spark timing. Very small Cox Model airplane engines, for instance, run equally well in either direction and it's not un-common for them to start backwards as they come up on compression, bounce back without going over TDC (top dead center), and then fire and run in reverse.

I guess that you almost stalled the engine starting out, the piston didn't quite make it past TDC, and the plug fired just about the time the piston stopped.  The piston was then pushed down and the engine began running backwards, with a delayed spark being the only symptom.  You were probably too busy to notice the lack of power.

Cheers.

ntglover
User Rank
Iron
Was it a 2-cycle engine?
ntglover   7/22/2011 1:25:02 PM
NO RATINGS
I suspect your little 50 cc engine was a 2-cycle engine.  If for some reason the cranckshaft began rotating in the reverse direction - perhaps because of a near-stall on acceleration or a kickback from early ignition - you would have everything reversed.  Bingo - your one-speed forward would become a one-speed reverse. 

Plexus
User Rank
Iron
Must Have Been A 2-Stroke!
Plexus   7/22/2011 1:19:22 PM
NO RATINGS
The old two-stroke switch!  Some economy 2-stroke engine designs would reverse direction when seeing a throttle demand from an idle condition.



Partner Zone
Latest Analysis
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
Fifteen European research centers have launched EuroCPS to help European companies develop innovative products for the Internet of Things.
Get your Allman Brothers albums ready. The iconic Volkswagen Microbus may be poised for a comeback, and this time it could be electric.
In 2003, the world contained just over 500 million Internet-connected devices. By 2010, this figure had risen to 12.5 billion connected objects, almost six devices per individual with access to the Internet. Now, as we move into 2015, the number of connected 'things' is expected to reach 25 billion, ultimately edging toward 50 billion by the end of the decade.
NASA engineer Brian Trease studied abroad in Japan as a high school student and used to fold fast-food wrappers into cranes using origami techniques he learned in library books. Inspired by this, he began to imagine that origami could be applied to building spacecraft components, particularly solar panels that could one day send solar power from space to be used on earth.
More:Blogs|News
Design News Webinar Series
3/31/2015 11:00 a.m. California / 2:00 p.m. New York
2/25/2015 11:00 a.m. California / 2:00 p.m. New York
12/11/2014 8:00 a.m. California / 11:00 a.m. New York
5/7/2015 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 20 - 24, Taking the Internet of Things to the Cloud
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Last Archived Class
Sponsored by Proto Labs
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service