Originally Posted by
Kolunatic
I'm running the 3 port in my dingo with stock flywheel.you can't reach the flywheel until I replace it with bigger " brand specific" flywheel and clutch, so I use exhaust. Should I pinch off fuel at inlet and risk blowing a 10$ turbo plug? When I get the new 5 port I plan on getting new bigger flywheel and clutch with pipe etc. How should I kill the new engine?
Hi Kolunatic, you have a lot more chance of blowing plugs by blocking off the exhaust stinger. That is probably the worst way to stop a motor time after time. If you can't reach the flywheel, then let the motor sit for a few seconds and settle, then pinch the fuel line off firmly. With the engine at idle it won't run leanish for more than a second, and if you pinch the fuel line off hard enough will most likely just die straight away. Like Flanno mentioned above, it also removes a lot of the fuel etc from the crankcase, so if your finished for the day and are not going to after-run (naughty but it happens), then pinching off the line can go some way to limiting moisture in the crankcase.
As far as running the motor lean, I can't see this method of stopping your motor (at idle) really being a concern. Guys run out of fuel in heats or finals all the time, and the motor is doing full revs when it happens, and life goes on.
I think the key thing here is "at idle". It's no different to when you are running your motor dry at the end of the day with the glow starter attached until all the fuel is burned away. At idle or at starter box revolutions there will always be enough oil residue on the piston and sleeve to protect the motor at these very low speeds.
Originally Posted by
asaraneta
Dudes I have a few questions:
- I did my break in with my GX7R, done 8 tanks on cycle at 210-230
- After 8 tanks, cleaned the engine and cycled for 2 tanks at 230
- After 2 tanks, I checked the plug and saw the plug busted (filament/coil cut in middle)
- Changed the plug and run the engine on track this time 2 tanks at max 3/4 throttle at 3-4 seconds.
My concern is when I did the same break in with my GX5R, the filament cut, that time the portion of the filament cut went into the chamber and damaged the piston and sleeve.
Since this is the second time happened during break in (bust the plugs), I am thinking the the plug must be pretty much close to the piston (using stock 2 shims) during combustion process. Does anybody had the same problem as mine? If I add 1 shim, does this solve the problem?
Appreciate any help could be given.
Popping plugs buring break in is not uncommon. They don't like being continually exposed to an over rich mixture. I often find they will survive the first 8 or so tanks rich, but then when you start to lean the motor out towards the end of the run-in cylcle the plug will perish. I think it's to do with the coil getting glugged up with oil from the rich mixture. Then when you lean things out and the temps increase, the oil burns off the coil, but oil burns a lot hotter than methanol/nitro mix, and the excessive heat of the oil residue burning off around the coil destroys it.
Best idea is to change the plug for a new one when you start to lean things out.