Originally Posted by
ozziii
My engine was also very tight, had to use a screw driver on the flywheel a fair few times to get the piston unstuck, that was with my modified GX5-R Godzilla engine that had a matched piston & sleeve, pre-heating makes a big difference, but for the first few tanks I was having trouble because I could only pre-heat to 160F so decided to keep the engine going & run a few tanks together instead of just one, saved alot of stuffing around & probably saved my starter box from stuffing up completely as well. Slightly loosening the glow plug made things a little easier too.
The GX5 and the R version were great motors, and even better once Mark had done his thing on them, I also had GX7Rs and a MM66 the black head version, very fast!
Those motors had the fit from new just right, quite tight for the first 5 tanks then they started to come good, any motor that is still locking up after a few litres is just too un matched for a factory std fit, i'd hate to try and start one cold if you had no way of pre-heating.