Decipher a serial number?

[GMJim]

I'm planning on putting a Preditor 212 engine in my grandsons Baja Dirt Bug and some posts I've read say this engine may not fit in the frame of certain bikes without some modifications. Is there a way to decipher the serial number to see how old the bike is?
Thanks

 

[Charles S]

I don't know about Baja serial numbers but there were two styles of Baja Doodle Bug frames, the 1st gen with a traditional looking frame (straight/horizontal upper/lower tubes) and the 2nd gen with the bent/angled upper/lower tubes. They put various model names on them, Doodle Bug, Dirt Bug, Racer, Blitz... You should be able to find plenty of Predator swap threads for both frame types in this section. As far as I know, a Predator 212 should fit in either frame without much trouble.

http://www.bajamotorsports.com/categories/minibikes

https://www.oldminibikes.com/forum/index.php?threads/baja-blitz-motor-upgrade.169736/ (1st gen)

https://oldminibikes.com/forum/index.php?threads/did-my-first-predator-swap-today.146269/ (2nd gen)

 

[GMJim]

Thanks for the reply and info. I guess I have the 1st. gen model. Based on the pictures I've seen on the forum the Preditor 212 isn't a direct replacement. I'll have to fab up a clutch/chain guard somehow and it looks like it's a bit wider? Chain alignment?

 

[Strigoi]

Pick up one of the engine adapter plates. They make installation super easy and you'll just need to drill/slot a couple of holes at most. That, the engine and a 3/4" bore clutch and you'll pretty much be good to go. I'd also suggest getting some good quality chain. I generally use RLV chain. A chain tool is a must as far as I'm concerned as well.

Getting the throttle set up is the biggest pain in the ass of the whole swap. Another thing to consider is a sprocket adapter. That way you can run split sprockets for karts if you want to mess around with the gearing.

I've never run a chain guard, so that may need some modifying. You'll need to figure out a clutch guard too (see link below).

https://www.gopowersports.com/fully-adjustable-motor-plate-small-block/

https://www.gopowersports.com/12t-3-4-bore-max-torque-centrifugal-clutch-35/

https://www.gopowersports.com/rlv-gold-on-black-35-chain-5ft-roll-xtreme-performance/

https://www.gopowersports.com/5-16-delux-chain-breaker-35/ (sold out at GPS, but can be found elsewhere easily)

https://www.gopowersports.com/universal-sprocket-adapter/

https://www.gopowersports.com/racing-performance-parts/chains-and-sprockets/35-split-sprockets/

This is a bit pricey for a clutch guard, but they're custom made and he does a good job. I've got one and it's a nice piece. I attached a pic showing it on my Doodlebug.

https://www.metalfabcreations.com/product-page/clutch-gaurd-cage

Edit: Since you're adding more power, more braking is a must as well. While I hate these and have personally seen too many fail, they're the only bolt-on option out there right now. They work well, just be sure to check it before every ride though. I've had 2 fail and two of my friends had the same thing happen as well. 3 of those 4 times ended up with having zero braking.

https://www.gopowersports.com/mini-bike-brake-system/

 

[GMJim]

Pick up one of the engine adapter plates. They make installation super easy and you'll just need to drill/slot a couple of holes at most. That, the engine and a 3/4" bore clutch and you'll pretty much be good to go. I'd also suggest getting some good quality chain. I generally use RLV chain. A chain tool is a must as far as I'm concerned as well.

Getting the throttle set up is the biggest pain in the ass of the whole swap. Another thing to consider is a sprocket adapter. That way you can run split sprockets for karts if you want to mess around with the gearing.

I've never run a chain guard, so that may need some modifying. You'll need to figure out a clutch guard too (see link below).

https://www.gopowersports.com/fully-adjustable-motor-plate-small-block/

https://www.gopowersports.com/12t-3-4-bore-max-torque-centrifugal-clutch-35/

https://www.gopowersports.com/rlv-gold-on-black-35-chain-5ft-roll-xtreme-performance/

https://www.gopowersports.com/5-16-delux-chain-breaker-35/ (sold out at GPS, but can be found elsewhere easily)

https://www.gopowersports.com/universal-sprocket-adapter/

https://www.gopowersports.com/racing-performance-parts/chains-and-sprockets/35-split-sprockets/

This is a bit pricey for a clutch guard, but they're custom made and he does a good job. I've got one and it's a nice piece. I attached a pic showing it on my Doodlebug.

https://www.metalfabcreations.com/product-page/clutch-gaurd-cage

Edit: Since you're adding more power, more braking is a must as well. While I hate these and have personally seen too many fail, they're the only bolt-on option out there right now. They work well, just be sure to check it before every ride though. I've had 2 fail and two of my friends had the same thing happen as well. 3 of those 4 times ended up with having zero braking.

https://www.gopowersports.com/mini-bike-brake-system/

Thanks very much for the info! I'm a mechanic so ok there but not familiar with what and where to buy for these bikes. This info is very helpful! Seems like there's a forum for just about anything.