- Sat Aug 10, 2019 7:29 am
#84680
Hi All...
I've built a new competition Bullet engine for my RE based scrambler but I'm unable to kick start it.
In short, the engine is a mix of Indian and British made parts. A Redditch case, 612 cc via a Hitchcock crank and a new old stock 'big head', ported and polished. 5 speed box. I have measured the comp. ration to be 11.3:1, about where I wanted it, a dash higher than planned maybe. I have 100LL Avgas in the tank.
The problem seems to be that the flywheel does not have enough energy to take the piston over TDC against the compression. My starting routine has always been to bring the piston up towards TDC on the comp. stroke, decompress, nudge the piston on a little more, bring the kick start back up and give it a jolly good kick. I'm pretty fit and strong, I feel that I can kick an engine pretty hard if needs be. The kick start lever runs out of stroke before the piston reaches the next comp. stroke although the flywheel caries the piston over and off it goes. Now with the new high compression engine, the piston just bounces off the compression.
My mate towed me on the bike with the Land Rover to see if the engine was fundamentally ok. It starts relatively easily provided the back wheel doesn't lock and although carb tuning is needed, it's a really fierce engine, sounds great and picks up the front wheel with little effort. These first short tests seems to show it has the grunt I was looking for. This is not a road bike...!
So, given that Land Rover tow-starts are a dash inconvenient, does anyone here have experience with high compression Bullet engines and the starting of? Is there a technique that I'm missing? Is there a known max. comp. ratio that can be kicked?
Thoughts are welcome.... R.
I've built a new competition Bullet engine for my RE based scrambler but I'm unable to kick start it.
In short, the engine is a mix of Indian and British made parts. A Redditch case, 612 cc via a Hitchcock crank and a new old stock 'big head', ported and polished. 5 speed box. I have measured the comp. ration to be 11.3:1, about where I wanted it, a dash higher than planned maybe. I have 100LL Avgas in the tank.
The problem seems to be that the flywheel does not have enough energy to take the piston over TDC against the compression. My starting routine has always been to bring the piston up towards TDC on the comp. stroke, decompress, nudge the piston on a little more, bring the kick start back up and give it a jolly good kick. I'm pretty fit and strong, I feel that I can kick an engine pretty hard if needs be. The kick start lever runs out of stroke before the piston reaches the next comp. stroke although the flywheel caries the piston over and off it goes. Now with the new high compression engine, the piston just bounces off the compression.
My mate towed me on the bike with the Land Rover to see if the engine was fundamentally ok. It starts relatively easily provided the back wheel doesn't lock and although carb tuning is needed, it's a really fierce engine, sounds great and picks up the front wheel with little effort. These first short tests seems to show it has the grunt I was looking for. This is not a road bike...!
So, given that Land Rover tow-starts are a dash inconvenient, does anyone here have experience with high compression Bullet engines and the starting of? Is there a technique that I'm missing? Is there a known max. comp. ratio that can be kicked?
Thoughts are welcome.... R.