Mini Bike Engine Swap – HRM Adjustable Motor Mount

mini bike engine swap

HRM Adjustable Motor Mount

The HRM Engine Mount Plate (formally known as PMR) was designed by us as an easy way to do a Mini Bike or Go kart engine install. This plate works great for doing a mini bike engine swaps on the Baja Doodle Bug, Dirt Bug, Racer Motovox, Monster Moto 80, Go Karts and Drift Trike projects and more. It lets you easily install a common 4-7 hp horizontal shaft engine in just about anything. We came up with this product design back in 2009 and it has been very popular.

This mount system lets you have left to right engine adjustment for precise sprocket alignment. Front to rear adjustments for chain tension can easily be done using one wrench to loosen the bottom nuts. This plate solves the problem of having to slot mounting holes in the exact location to achieve proper chain alignment.

 This HRM adjustable Mount system is designed for engines using an industry standard bolt hole spacing. Examples. Honda GX 120-200 series, Honda 6.5 Clones. HF Predator 212cc, Briggs, Tec’ , Subaru  and other brands in the 4-7hp HP range. For Mini Bike Drag Racers it has been proven capable of handling built engines producing 15-30hp. The HRM Adjustable Motor Mount plates come with full instruction sheets and tech support.

Our new Adjustable Motor Mount plates have the traditional aluminum finish and the HRM Logo on them.

Please Note. If you see this Adjustable Motor Mount design online being sold by another company. And it does not have the HRM logo. They have simply ordered one of our mount systems and directly copied it. Rather than taking the time themselves to do any product design or R&D work  Please support original designers and manufacturers.

Thank you for your support! And to all our good customers who have purchased this mount from us!

Brad and Shaun @

Instructions for installation HRM motor mount instruction sheet




mini bike engine swap



6 thoughts on “Mini Bike Engine Swap – HRM Adjustable Motor Mount

  1. steven m kennedy says:

    I am wondering if this will work in an MM80 with a spredator 212 stock air cleaner and exhaust or if they will need to be modded.

  2. Ron Johnson says:

    How thick is this mounting plate?

    I’ve got a Coleman BT200x with a TAV setup that requires motor clearance risers of about 1 inch that I’d love to replace as I need a little lateral adjustment for proper chain clearance I currently do not have. I’m just curious if I can ditch the spacers entirely if I use this product.



  3. tony myers says:

    those jack shaft that mount on the engine block i have one of those side shaft baja 97cc im trying to make an motorize custom beach cruiser 29” in rim in the back 26” in in the front is there any way to do an combination from the clutch from transmission to chain to rim

    • hotrodminibike says:

      Yes the Jack Shaft system we sell will fit on the 97cc engine. We have had lots of customers use them for Motorized bicycle projects. And our plate design we came up with 10 years ago is now being copied by numerous companies now selling MB parts and kits. When you know what your rear sprocket count is you can use a jack shaft gear ratio calculator on line to chose the sprockets for the JS sprockets. It can be custom ordered by sending us an email too.

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