Yamaha SR400 Scrambler by Purpose Built Moto

Yamaha SR400 Scrambler

Tom Gilroy of Purpose Built Moto has quickly made a name for himself in the Australian custom motorcycle world and beyond. His scrambler builds have been hugely popular and both amateur and professional builders around the world have been using his custom-built parts.

Yamaha SR400 Scrambler

Now Tom is back with his best scrambler yet, based on a 1986 Yamaha SR400 built to handle the customer’s off-road shortcut to his workplace.  Given that many shops have tackled the SR400, Tom knew that the Purpose Built Moto would have to be executed to the highest standard. Below, we get the full story on this bad and beautiful thumper.

Yamaha SR400 Scrambler: Builder Intervier

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

Purpose Built Moto has now grown beyond what I could have thought a year ago. Thanks to my work in the garage, and supplying high quality parts to other builders around the world, I’ve been able to move from my home garage into a full size workshop and be able to take on more work and bigger projects (and hopefully pump out better bikes).

Yamaha SR400 Scrambler

• What’s the make, model, and year of the bike?

1986 Yamaha SR400

Yamaha SR400 Scrambler

• Why was this bike built?

Julian the rider wanted a bike able to handle his off-road shortcut to work. The styling was left up to me, I’ve developed my own style with scramblers and I wanted this to represent everything I think a fun off-road custom should be.

Yamaha SR400 Scrambler

• What was the design concept and what influenced the build?

The SR400 had to function first and foremost, so a good amount of thought went into rider position and suspension/handling. As far as the styling on the bike goes, its been given a tracker edge with the peanut tank and seat shape. The major standout of the concept is the bold colour way used, with the bright yellow accents that catch your eye and demand you keep staring!

Yamaha SR400 Scrambler

• What custom work was done to the bike?

The SR400 was stripped to the core. New suspension, subframe, fuel tank, and a seat built and upholstered 100% in house.

Yamaha SR400 Scrambler

Motor stripped, checked over, painted, and the cases were brush finished by hand. You don’t put chrome on dirt bikes…

Yamaha SR400 Scrambler

The carb was pulled down, cleaned and re-jetted to suit the new exhaust and yellow top DNA performance filter.

Yamaha SR400 Scrambler

The lighting + switches came from the Purpose Built Moto product range and the headlight is a new prototype of a 4.5” LED headlight set for release this year.

Yamaha SR400 Scrambler

The exhaust was built in-house and one of the first I’ve done. The aggressive kick up sits well with the scrambler style and the Protaper bars with Heidenau K60 tyres keep that off road feel flowing from top to bottom on the bike.

Yamaha SR400 ScramblerYamaha SR400 Scrambler

• How would you classify this bike?

200% Scrambler

Yamaha SR400 Scrambler

• Was there anything done during this build that you are particularly proud of?

The exhaust I think came out really well, its raw, throws a growling note and flows with the major parts of the design.

Yamaha SR400 Scrambler

The most important part of any Purpose Built Moto Scrambler is how it feels and rides.

Yamaha SR400 Scrambler

The look when you’re walking up to it — the yellow on black with the wide MX bars and tidy, tucked in LED lighting giving a minimal race look.

Yamaha SR400 Scrambler

The upright and in control rider position and that deep bellowing exhaust note when you kick the thumper over. Then the responsive handling + power when tipping it into a slide through a corner, you can’t deny the ear to ear smile this bike gives you no matter where you’re riding it. That’s the most special thing about this ride.

Yamaha SR400 Scrambler

Photo/Video Credits

Electric Bubble:  https://www.electricbubble.com.au/

Follow the Builder

Facebook: https://facebook.com/purposebuiltmoto/
Instagram: @purpose_built_moto


  1. Needs side covers.

  2. Nice build.
    I would have gone for a more off road style tank, maybe a Honda XL 185 item, and more colour. And side panels/number boards.

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