Friday , 19 October 2018

The RC Doctor: Buzzing Losi ROSS Starter System

Buzzing Losi ROSS Starter System

Hey Doc-
I have one of Losi’s TEN SCT Nitro trucks. It’s equipped with the ROSS starter system but for some reason, when I push the button, I get a buzzing sound and it won’t turn over the motor. I tried installing a fresh battery but that didn’t seem to fix the problem.

Any ideas on what’s going on? Thanks!


Hi Chris,
I actually had one of those trucks awhile back and LOVED the onboard starting system. I never had any issues with my ROSS, but I have heard that they can sometimes get ‘clogged’ and bind up. So, here’s a few suggestions to try out.

The first might be that something is binding in the starting system; bend shaft, bound bearing – something like that. Since it’s buzzing, we know that power is being applied to the motor. Remove the engine and pull the ROSS system. You can, at this time, press the button to see if the ROSS system works – just keep your fingers clear from any moving parts. If the buzzing persists, it’s most likely something in the ROSS gearbox (most likely the motor). Disassemble and inspect – replace or repair the problem.

If the ROSS system works fine, it could be the engine. Best case scenario would be that the piston is stuck in the up position; break it free and try the ROSS system again. Worse case scenario, the engine has some major issues.

If I’m correct, you can bumpstart the motor from underneath. You could find a friend that runs nitro and see if you can borrow their box to try and start it. I would, however, do this as a last resort. If there is a minor issue with the engine, forcing it to start could turn it into a major issue.

Good luck!
The Doc

About Tony Phalen

Tony Phalen - As an avid RC enthusiast, Tony has been building, bashing and racing RC Cars for over 25 years. He has raced everything from 1:18th scale trucks to 1:5 scale motorcycles and everything in-between. He's also worked on both sides of the industry fence; working at and with many major manufacturers (as well as being a sponsored driver) to working for a high-profile industry magazine. During this time he has learned many tricks, tips and techniques and has transferred that knowledge to CompetitionX - the most informative RC website on the internet! More articles by Tony Phalen

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