Engine Selection - Please Help!

[JHD331]

:hammer:

So, i just got a rolling frame from Gigantic Bad Dog as a Christmas present from my younger brother. Now, both of us are in our late 20's and 30's and haven't built a mini bike in 15-ish years, so we are a bit rusty.

We have been told by BD that it is recommended that we use the Tecumseh engines with 3/4" drive, as that is the bolt pattern for the engine on the frame.

I wanted to reach out to the community and ask the following questions, however as i am quite rusty.

1. Should we go with 8 or 10HP?
2. We will be using the Torque Converter that Bad Dog sells on his website, but are there other options which are good? We have been told this one bolts up to the Tecumseh the easiest.
3. Ideally, i would like to have an engine with an alternator, but is that even an option? I want to have a headlight, and tail light as well.
4. When selecting the engine i assume we need a manual throttle?

Thanks so much for your insight! Appreciated!

 

[CarPlayLB]

Tecumseh? Huh? I dunno why they would say that as Tecumseh has not been around for a while!

If it was me, I'd go the Harbor Freight and buy a $99.00 Predator 212 motor. There are a ton of upgrades available to get a reliable, easy starting 8-10 HP. Most of the small engines have the same bolt pattern...kind of an industry standard thing.

Alternator? Yikes! look or an old snowblower engine!

Whatever you choose, you will need a throttle hook up

 

[JHD331]

Any suggestions on torque converters?

 

[CarPlayLB]

I like the genuine Comet converters, and that is what I have purchased in the past.
https://www.OldMiniBikes.com/TAV2-1-Drive-12T-35-C218352A.html?category_id=1608

but a lot of members here are also successful with the aftermarket pieces
https://www.OldMiniBikes.com/Torque-Converter-3-4-Bore-35-Chain.html

Either way you go, gearing will be important!

 

[Harleys Papa]

8 and 10 horse Tecumseh's all have 1" shafts so make sure you get your motor before you order a torque converter :thumbsup:

 

[JJsiahmoto]

I have built 3 Mini Bikes in the last week. I have put a Predator 212cc from HF on all three. They are by far the cheapest and most reliable engines. They also have a wide variety of parts. They are easy to hook a throttle up. You can hook up a charger to power lights and so on it. I'd rather just get a small ATV battery. On my rupp I put a comet 20 series clutch. THOSE work great. Also 30 series and 40 do too. I bought 3 cheap $12 throttles from Amazon and they work great. Let me know if you need more help!

 

[JJsiahmoto]

There are kits to hook up an alternator on the predator but i think you need to have a flywheel with magnets to charge!

 

[JHD331]

8 and 10 horse Tecumseh's all have 1" shafts so make sure you get your motor before you order a torque converter :thumbsup:

I am finding a bunch of 10HP with manual throttle assemblies that have a 3/4" drive. Any issues with 3/4" drive?

 

[JHD331]

I like the genuine Comet converters, and that is what I have purchased in the past.
https://www.OldMiniBikes.com/TAV2-1-Drive-12T-35-C218352A.html?category_id=1608

but a lot of members here are also successful with the aftermarket pieces
https://www.OldMiniBikes.com/Torque-Converter-3-4-Bore-35-Chain.html

Either way you go, gearing will be important!

Gearing wise, do you have any recommendations what i should be looking for? I weigh 205lbs and the Bad Dog Gigantic is quite heavy as well.

If you can provide any insight, please let me know! Thanks!

 

[gumpit]

I'm 350 pounds and with a 212cc Harbor Freight Predator and a torque converter it will carry you anywhere you need to go....