Robbo60

UPDATE Since invoking the starting fix we (my Son and I) have done a few rides and completed a club competition. The bike starts from stone cold 2nd kick. During the event we stopped to talk about the course and the bike can be kicked into life first go while in gear!!! Woo Hoo! I have now bought a second 2011 Ossa 280i; wired in my fix, removed plug and oiled the bore, drained and replaced the fuel with new as the bike had Sat unstarted for over a year. Pressed the button, heard the fuel pump prime the system, one kick and she started. One kick! It continues to start with ease, even in gear once warm.

Hi Konrad, thanks for the info. Fundamentally all I did was swap out the 9V battery for a 14.8 volt battery.... Well over 10 starts from cold now, the highest kick count for a start is 3, often only 2 for a start. I hold the battery button in until the bike starts, this is maybe 10 to 15 seconds? for a 3 kick effort. I am so happy! The bike is an awesome machine that is now super easy to start hot or cold, out at the trail or out in the street. Cheers!

Hello, New to trials, not new to bikes. I very recently bought a 2011 280i from a mate, he has not used the bike for some time and may even have lost interest in the bike given it was so much hard work to start. It had the 9volt battery mod but I found that the handlebar push button to engage the battery was not functioning. So the bike took a million kicks to start by which time you needed a lie down to recover..... I replaced the switch which improved things but around 10 kicks to light the fire was not uncommon. I checked spark and it was fat and healthy, I had drained and replaced the pre-mix and I had tidied up the horrendous job that had been done during the 9 V battery install, nothing soldered everything poorly wrapped in miles of electrical tape. Still hard to start. I found that the CDI capacitor bleeds off its charge to the 'system' in a short time. If I disconnected the CDI from the rest of the system it would hold the charge for ages. So with everything connected after a minute or so you're back to square one except perhaps the bike is now warm. I carried out some tests; I ran the bike, stopped it and measured the 'system' voltage. Unsurprisingly it was 14.4 volts on my Fluke meter so I figured the application of 9 volts from a tiny lithium is a half baked measure. I made up a 14.8 volt rechargeable lithium Ion battery pack from 4 x 700 mAh 3.7 volt cells and used Deans connectors so I can easily disconnect to charge it up as required.. By the time I had finished fooling about and doing chores for the missus the bike had been un-started for 2 days. I wired in the new battery pack and started to kick her over, the bike fired up from stone cold on the second kick. I let it cool back down, same result. Same again on a third go. Called my Son (we are both electrical instrument and control technicians) (but I'm retired) and he could not believe no one has already done this, So please forgive me if I am teaching people how to suck eggs. I have not read hours of forums nor is my local Trials dealer aware of this 14.8 volt battery modification (he appears to know a ton of data on Ossa Trials bikes), he asked me to write this post. Now when I press the 'battery' button the fuel pump happily runs priming the system, over several tests this takes 2 seconds. The current drain from the battery pack is 2.5 A for that 2 seconds, after which while still holding the button down the drain is only about 100 mA. The pack is 'rated' at 700 mAh, lets say that the stated 700 mAh is optimistic and additionally the 2.5 Amp (4C) drain taxes the battery so its only good for 25% of 700 mAh. I calculate that even at 25% capacity the battery is good for 4 minutes at 2.5 A. Enough for over 100 starts between recharges. Sincerely hope this is a help to someone out there. Cheers