Ideas for Made in America bikes

[Will'smotobikes19]

Diaphragm carbs are junk in my opinion. I prefer bowl carburetors. Look at any weedeater or chainsaw with age that isn't maintained by a lawn service. That little piece will dry up and no longer be pliable and won't allow the engine to run. I have a Tecumseh and it has an intake that draws fuel upwards instead of straight into the intake. I see no possible way that could help the engine but make it harder to start. If you wanted the crank to stop moving you cannot simply insert a piston stop since the spark plug is over the valves and not the piston. I'm sure tecumseh was an ok engine back in its day but has become old technology plus no cylinder liner. Cars and cameras have proved briggs flatheads are quite usable with mikuni carburetors.

 

[mark20]

Diaphragm carbs are junk in my opinion. I prefer bowl carburetors. Look at any weedeater or chainsaw with age that isn't maintained by a lawn service. That little piece will dry up and no longer be pliable and won't allow the engine to run. I have a Tecumseh and it has an intake that draws fuel upwards instead of straight into the intake. I see no possible way that could help the engine but make it harder to start. If you wanted the crank to stop moving you cannot simply insert a piston stop since the spark plug is over the valves and not the piston. I'm sure tecumseh was an ok engine back in its day but has become old technology plus no cylinder liner. Cars and cameras have proved briggs flatheads are quite usable with mikuni carburetors.

The main reason techumsehs have that weird intake is due to space constraints, due to the gas tank being on the opposite side (unlike the Briggs), the more space they save, the more things it can go on (ie, tillers, snowblowers, etc) the more sales they get.

Personally, i like diaphragm carbs IF you can get replacement diaphragms, I gotta give props to Briggs and Stratton for still producing and selling diaphragm kits for their flatheads (that were discounted 30 something years ago) at a very reasonable price (under 4$ in most hardware stores)

the main advantage is that diaphragm carbs can be adjusted infinitely due to the set screws, so there is no need for buying and changing jets.

also the motor can be ran at any angle (theoretically, due to not needing gravity to push the float down)

 

[JerryAssburger]

The main reason techumsehs have that weird intake is due to space constraints, due to the gas tank being on the opposite side (unlike the Briggs), the more space they save, the more things it can go on (ie, tillers, snowblowers, etc) the more sales they get.

Personally, i like diaphragm carbs IF you can get replacement diaphragms, I gotta give props to Briggs and Stratton for still producing and selling diaphragm kits for their flatheads (that were discounted 30 something years ago) at a very reasonable price (under 4$ in most hardware stores)

the main advantage is that diaphragm carbs can be adjusted infinitely due to the set screws, so there is no need for buying and changing jets.

also the motor can be ran at any angle (theoretically, due to not needing gravity to push the float down)

AGREED. My "Love Affair" with diaphragm carbs started with an old air-cooled snowmobile twin with a Tillotson carburetor. You could be flying down the street and adjust the high-speed jet as you were going! I'm not sure where the hate for the Tecumsehs came from, but they had some pretty good motors, too. (The H35 is on my wish-list).... I'd think they would also respond well to a decent Mikuni slapped on- I thinks B/S flatties are a lot easier to find parts for.

 

[mark20]

AGREED. My "Love Affair" with diaphragm carbs started with an old air-cooled snowmobile twin with a Tillotson carburetor. You could be flying down the street and adjust the high-speed jet as you were going! I'm not sure where the hate for the Tecumsehs came from, but they had some pretty good motors, too. (The H35 is on my wish-list).... I'd think they would also respond well to a decent Mikuni slapped on- I thinks B/S flatties are a lot easier to find parts for.

Main thing is connecting rods, 4 stroke techumsehs are a long stroke engine (ie high piston speeds at low rpm) and weren't meant to run at 5-6k+ Pair that with the material used for the rods would useally lead them to stretch and snap.

this was mostly famous with the larger 8+ hp snowblower engines, since the governor linkage would freeze up and run the engine full bore, resulting in a broken rod after a few hours of snowblowing.


Personally, I LOVE techumsehs, there one of the easier carbs to tune, also dead simple Jet cleaning (just unscrew the float bowl screw, and clean that jet)

 

[Will'smotobikes19]

They do not and I mean do not make the bracket for the points and condenser anymore. All I could find is this but the laminated plates look like an accordion.

h35 coil - Google Search

There is also aftermarket condenser and points but still no bracket that holds those steel plates.

Ignition Set Point & Condenser for Tecumseh VM80, 1500-1550A, 1550A-1500, TVM170 | eBay

Go Kart Parts. Power Sports. Deck Belt, 1/2" x 104" for John Deere GX20072, GY20570, UC32283, Rotary 10436. Deck Belt, 1/2" x 104" for Craftsman SPM215471655, Stens 265-826, 265826. Deck Belt, 1/2" x 104" for Sabre GX20072, GY20570, Oregon 175-919, 175919.

www.ebay.com

 

[mark20]

I'd use a NOVA II anyway, turns points into electronic ignition, dead simple to set up, doesn't give you grief of having no spark after sitting for a long time.

 

[Will'smotobikes19]

Thats only briggs? plus I think its just as many parts to convert it.

 

[mark20]

Thats only briggs? plus I think its just as many parts to convert it.

No, any engine with a flywheel magneto-style ignition it'll work on.

costs about 8$ and its a single part

 

[LewieBike]

Ya but those were 1960's subarus right? and the few other odd cars. Fact is everyone likes 2 strokes on here this thread is about making a bike out of American components but the truth is even briggs and stratton makes all their engines (overpriced) with chinese parts and look just like a harbor freight motor except maybe the big vtwin engines. They just use gross torque and cubic inch that's the only difference.

Nope, Made in Sweden SAAB the jet aircraft maker They started making cars back in 1950 with a 2 cylinder 750 cc 25 H.P. sedan that looks a lot like the last of the Bullnose 1960's 96's. This is what my 1962 looked like, (not my car..)

36 hp, old school Schnerle ported long stroke, water cooled, 850cc, 3 cylinder two stroker. 33:1 pre-mix. Wall of torque from 1700 RPM upwards.

 

[LewieBike]

Diaphragm carbs are junk in my opinion. I prefer bowl carburetors. Look at any weedeater or chainsaw with age that isn't maintained by a lawn service. That little piece will dry up and no longer be pliable and won't allow the engine to run. I have a Tecumseh and it has an intake that draws fuel upwards instead of straight into the intake. I see no possible way that could help the engine but make it harder to start. If you wanted the crank to stop moving you cannot simply insert a piston stop since the spark plug is over the valves and not the piston. I'm sure tecumseh was an ok engine back in its day but has become old technology plus no cylinder liner. Cars and cameras have proved briggs flatheads are quite usable with mikuni carburetors.

My experience is contrary. I've had pumper carbs that have put in decades of service. I have four Chainsaws/Metal-Cutoff saws and a big weedwacker that all run pumpers that were made in the 1990's or earlier that are still running today on their original carbs. Because I use non ethanol, mix my gas-oil precisely and don't store these engines unused for long periods of time with gas in them.