This malfunction will end your GT750 ride

[Evans Ward]

Had this happen last Sunday while on a ride. Limped it home riding very gingerly. Never saw red on the temp gauge but crept close. I have a new factory plastic gear drive and will replace the pin, washer, and E clip too. Did find a large flat washer that fell out when I removed the starter cover- anyone know where that belongs? It is pictured in the 2nd pic at bottom. I drained gear oil which looked good with no metallic particles. Drained coolant and will flush system again and changing head gasket (NOS factory one). Have the head off and will check it per service manual specs for warpage with a straight edge. Also have a nice spare head just in case. Piston crowns looked good and decarbonized them yesterday too. One other question- is there a large magnet anywhere under the starter cover? I also have the Accent electronic ignition. Thanks for any help!

[Evans Ward]

A member on the Kettle Club Forum helped me ID it- fits on the starter idler gear shaft.

[Craig380]

What a pain in the @ss that it broke up, but you caught it in time and can fix it.

Bloody Japanese crap with built-in obsolescence, only lasting 40+ years

[rngdng]

Had this happen last Sunday while on a ride. Limped it home riding very gingerly. Never saw red on the temp gauge but crept close. I have a new factory plastic gear drive and will replace the pin, washer, and E clip too. Did find a large flat washer that fell out when I removed the starter cover- anyone know where that belongs? It is pictured in the 2nd pic at bottom. I drained gear oil which looked good with no metallic particles. Drained coolant and will flush system again and changing head gasket (NOS factory one). Have the head off and will check it per service manual specs for warpage with a straight edge. Also have a nice spare head just in case. Piston crowns looked good and decarbonized them yesterday too. One other question- is there a large magnet anywhere under the starter cover? I also have the Accent electronic ignition. Thanks for any help!

I have repaired cracked ones, but not that one!!!

[johnakay]

is there any particular reasons why these are made out of plastic?
why not use brass etc.

[Evans Ward]

is there any particular reasons why these are made out of plastic?
why not use brass etc.

I believe it was designed to break before any further extensive damage could be done.

[Craig380]

I think Suzuki originally specified nylon / plastic for quieter running compared to a metal gear set: on the 380 triples the gear that drives the contact breaker shaft from the crank is also nylon.

It seems a bit daft when you consider the general racket you get from 2-strokes anyway

When you think about it, it lasted 40+ years, Suzuki never designed the engines to last THAT long

[Evans Ward]

Measured the head for flatness along with the newly acquired one. Both are fully flat with no issues of warpage at all per the 6 different measurement points from factory service manual. This is surprising on the one from the bike based on those temps shown on the gauge and distance back. Suzuki made these things very robust. Hope to have it back together and running by the weekend.

[Evans Ward]

Flushed cooling system x 2 and adjusted hose clamps for leakage. Used new thermostat, new OEM head gasket. All back together now! Trying to get this machine road ready and reliable.