Lawn-Boy Model 'E' Twins (mockup)

[Jerryburger]

both engines are attached to a live axle.

Ooops. Didn't catch that. Gotta quit being lazy and go back through this thread. I was thinking independantly driven wheels for 2 reasons- 1.) I think that's how most of the older dual set-ups were, 2.) it eliminates the differential/live axle debate by allowing both wheels to receive power, yet spin at different speeds due to cornering loads, allowing the kart to corner better.
We all look at the same thing and see differently. (See "Rawshack Test)

 

[blank]

Dual engine eh? Is there any syncing needed? Abd if so what settings do you have to play with..i assume the carb to get them reving at the same speed...

 

[Russ2251]

Some changes have to be made to driveline, but is otherwise completed.
Amazing performance considering these are (were) vertical shaft, "run of the mill", lawnmower engines.

 

[Kaptain Krunch]

Very nice, whats the top speed? That frame looks just like mine, asuza i think? I extended mine 1ft, helped quite a bit, i was pretty cramped before.

 

[Russ2251]

whats the top speed?

Unknown, but around mid 50's.

That frame looks just like mine, asuza i think?

It is Azusa and is only minimally modified to make way for 2 engines. At 5' 10" I drive it comfortably so extending frame was not necessary. I did not want to jeopardize frame geometry. Worked out well for me.

 

[EagleTalons]

Wow! That is quite a nice looking cart!

 

[brendonv]

Im currently putting a victa 160cc engine on my kart, how do those exhaust pipes go? How does it have any back pressure? Wouldnt it be extremely loud as well? Im using a motorized bike exhaust on mine, goes and looks good. Ive just made the engine mount and going to mount it all today.

 

[anderkart]

Super cool kart Russ

 

[Russ2251]

how do those exhaust pipes go?

Can you re-phrase that?

How does it have any back pressure?

2 cycle power plants don't require back pressure in the way that 4 cycles do and is a non-issue for me. Using a muffler only adds weight and robs potential power (15%?).

Wouldnt it be extremely loud as well?

It's more than extremely loud. Deafening would describe it. I run it in a non-residential area so I am free to do what I want. Early in the AM is the best time as parking lot is dead empty. I love the smell of smoldering rubber in the morning.
Thanx for kudos.

 

[Jerryburger]

Ahhh, so the new color signifies a New Purpose!..... Pretty danged cool. I wonder how Kibble is doing on his? I think what I love about karting is that Not a SINGLE ONE of us have built the same beast, but they all GO in their own sense of the word. I couldn't imagine how cool it would be to get them all together.

Nice job, Russ! Are you gonna shoot more video?

 

[TOO FAST]

What a great job on this build, Must be a blast to handle

 

[kibble]

Deafening would describe it.

I can vouch for that comment. LOL

I wonder how Kibble is doing on his?

Unfortunately it's still sitting there since I broke my clutch. Engine runs nicely but the whole clutch and jackshaft deal became a problem. When I get enough funds together I'm going to attempt to finish it. Life (and work) just get in the way of things.

 

[jr dragster T]

Nice kart Russ, I like it! I noticed you got rid of the sink trap pipe exhaust headers?

 

[Rickracer]

Those motors would run much better with expansion chambers. Chambers on a two stroke are like supercharging from the back end. There are lots of them available on Ebay. What kinda cubes are the motors? You could probably find pocket bike or similar chamber that would work well with some alterations, could be worth 20~30% more power with no other changes (aside from maybe some carb jetting). I threw an expansion chamber together for my grandsons 49cc pocketbike from scratch, and it made a WORLD of difference.

 

[Russ2251]

so the new color signifies a New Purpose!

Yes, it's chicken yellow. Next kart will be powered by chicken poop.

Are you gonna shoot more video?

Soon.

got rid of the sink trap pipe exhaust headers?

Not enough load bearing strength.

would run much better with expansion chambers

Agreed.
Main Idea was to keep cost$ and weight to a minimum. Expansion chambers are just too expensive. Pocket bike pipes are too small anyway. These engines are 141cc's (8.6 cu.in.) each. Typical pocket bikes are 49cc's.

 

[residentg]

Russ - I have 2 old briggs 5hp flatheads that I was going to use to built a 2-engine cart. are you using 2 centrifical clutches and 2 sprockets on the axle? I wanted to see if I could use a jackshaft and TaV somehow. I have not put too much thought into it yet - any ideas? JB

 

[Russ2251]

are you using 2 centrifical clutches and 2 sprockets on the axle?

Yes to both. TAV's are/were out of the question for my design. I was looking for the "old school" approach...that is...keep it simple, inexpensive, and light.
Good luck.

 

[crazycart]

So these are not duraforces correct? I get a few at the shop once in a while to repair... If not, have you considered dual duraforces?

I tore down an older round cyl lawnboy engine, its amazing how tuned DOWN these are. Some simple port work and they would really scream.

 

[Russ2251]

So these are not duraforces correct?

Incorrect. They are Duraforces.
Easily recognized by square cylinder fins and 4 bolt head. Circular cylinder fins would be models A, C, D and F. Model V has square fins, but head is not removable. Also, there are no differences between F's and V's other than outward appearance.
There is a model M...but I won't get into them.

 

[Russ2251]

Improved exhaust angle/new throttle cables

Noise levels were a little too much with pipes in almost upright position (inches away from ears). Pointing them back further makes a big difference. Distance from ears is now about 15".
My guess is that exhaust db levels are well over what OSHA recognizes as safe in any work place.
Not that I care what OSHA says...but 150db's (approx.) is kinda' uncomfortable.