Starting a motor

OK, this is not exactly a car question, but it does have to do with gas engines. I have an older gas powered chipper/shredder that is extremely hard to start. I want to put an electric motor from an old furnace blower on this to act as an electric starter motor. I have removed the rope pull and attached a pulley to the shaft. I then mounted the electric motor to the side of the unit and attached another pulley to that shaft and then routed a belt around them. But it does not have enough torque to get it going. Anyone know of a gear ratio between the two pulleys that would work to get this to work. I have tried a few combinations with what I have, but no luck. I hate to go spend money on something when I can possibly rig this to work. Any ideas out there???

I have modified a couple of old gas engines to start with a motor but I went another route. I just used a large electric drill to start the engine. Drills have a lot of torque. A furnace blower does not have enough torque when starting. A washing machine motor may do the trick if you don’t like the drill idea.

That motor will never work. A HVAC motor is a very low powered motor only good for constant speed and no load. Most of the time, hard starting is due to a lack of fuel. If you have no primer button, pull the plug and squirt a little gas from an oil can in the hole, then give it a pull and it’ll pop right off. That’s a lot easier. I tried the drill thing on an 8 HP and you really need a 1/2" drill or so to do it. Used to be kits available for about $10 from Northern Hydraulic but haven’t seen one in years. So either a regular starter motor kit for about $100 or a different motor.

Before the days of recoil starters when one wrapped a rope around a notched pulley, I could take a 1/4 horsepower motor off a furnace blower and put a belt between the electric motor and the pulley of the gasoline engine of about 3 horsepower. I would move the electric motor to let the belt slip and gradually turn over the gasoline engine. The gasoline engine would start turning over and eventually start.

A better solution, however, might be to find out why the gasoline engine engine on your chipper/shredder is hard to start. If it is an older engine with breaker points, I would replace these points along with the condenser.

A shot of starting fluid is all you need.

Bing’s right. squarrel cage blowers for furnaces require very little power, and the motors are unlikely to be able to turn over a gas engine.

What you’d need is a motor from a router, a planer, a drill press, or something of that sort with a bit more oomph.

I also agree with those that suggest a squirt of starter fluid to start it. It’s always worked for me with troublesome small engines.

And be sure the air filter is clean.