I have a hobbico engine starter, it's suppose to start up to a .90 size engine but mine has a hard time turning a .70 4 stroke, I'm using a 12 volt battery how can I get more tork? thx

Fourstrokes need bigger starters then two strokes. The numbers mentioned by starter manufacturers always apply to two strokes.

I use a Sullivan starter, but I power it with 12 nicads (4000 mAh), this gives a little extra power.

Some people in my club use small car engine starters (the junkyard community )... heavier, but a little more torque...

You could make your own high torque starter by mounting the flange from your starter on a battery powered drill. 700 to 800 rpm is more then enough to start your engine.

Hi!
How powerful is your 12V battery?? 7A, 9A or 12A?

Regards!
Jan K
Sweden

If you plan to be in RC for the long haul, go ahead and get a good starter. I have the Sullivan Dynatron. Beats the pants off a Hobico 180 HI-Tork. It easily starts my OS 1.60 FX, and my YS 120 FZ.

Either you're not using a good size well-charged 12V battery, or you don't have a good connection from the starter to the batter, or the brushes inside your starter are worn. Make sure your engine is not flooded either.

If everthing works good, your starter should turn over a .70 4stroke easily. That .70 has got to have some monster compression to give even a std duty starter trouble.

In my experience, 4stroke are actually easier to start than 2stroke. When you wind the prop backwards till you come up to compression (same as on a 2stroke) and engage the starter, the engine will spin about 1-3/4 turns with next to no resistance before encountering the compression stroke. This builds up some nice momentum and helps the starter turn the engine over. 2stroke can only spin free for about 2/3 turn before going up against compression.

I have a Dynatron with a single handle conversion. On 24V, it turns over my Poulan 46cc gasser with ease. Still, I keep a cheapo Tower Hobby HD starter around for my smaller (<1.20) engines to keep the wear and tear down on the Dynatron. There's nothing wrong with the less expensive starters. They don't have easily replaceable brushes (you can still replace them, I've done it before) and they have bushings instead of ball bearings.

Volfy
Did you mean the Dynatron or Megatron starter from Sullivan turns your engine? The Dynatron is just a slightly bigger version of the standard starter while the Megatron has handles.

It's all in the battery....forget those little LHS gel-cell
batteries. Go down to the Auto Zone, or whatever....
and invest about $30. in a garden tractor battery. A
wet cell.....mucho gusto....you will notice about a 50%
increase in the power of your starter motor, and you and
your buddies can run field chargers, and the like all day
without fazing it.

Get one with the plastic handle on it. This rig will crank
3000, and 4500 S.T.'s....cold....

If you want a small compact starter that turns 120 4-stroke, go with Kavan starter with 14.4 volt.
I suggest to replace the cone with blue one (MIller starter cone)

I've been using regular hi-torq starter with 12V pack, but was too heavy to carry around. All my engines starts with one touch with starter, so I decided to use Kavan with 7x 7.2V car packs. The battery last pretty long and never had problem.
Here is the picture of my starter.

It's the Dynatron. Sullivan makes single handle and dual handle conversion kits for this starter. I bought the single kit. This motor is rated for 12/24V duty (although I've run other 12V starter on 24V occasionally without much problem - probably shorten the life of the motor slightly as a result). The handle conversion helps managing the Dynatron at full torque nicely.

The Megatron is really for big gasser twins 60cc and up. I'm not playing in that league, yet.

I still don't get why planetary gears aren't used more often in these starters: you'd only need half the motor and still have twice the torque... I guess they're too expensive.

Compact 12V Starter $34.95
From Central Hobbies
Anyone tried this ?

http://www.centralhobbies.com/Electr...rs/compact.htm
5:1 Gear Reduction

2600 MAX RPM
Dimensions (Starter Only):
7-3/4" Overall Length
2-3/4" Hig
1-7/8" Wide
Weight: 2-1/2 lbs

Get a Sullivan Hi Torq. It is smaller than the Hobbico and can draw up to 25 amperes. It spins a 91 four stroke like it was a 1/2 A two cycle. I use a 24 ampere hour rated battery. Used to use a lawn mower battery.

I had a Hobbico 90 starter and it was just down right anemic, probably dirty brushes or something. Got the Sully and never looked back.

Cheers,

Chip