One of the anomalies of the Twinshock class, that after 1975, Yamaha’s went monoshock, with the De Carbon unit (okay there was the Geboers senior unit on a Suzuki before then), but the MX250 B of 1975 was the first production monoshock.
Picked up the bike from Rupert across the other side of Hereford, and he assured me that it ran, despite its refusal to start on the night. After the SC500 ignition saga, I was a little skeptical but hey, it will be alright. Rupert already has a YZ250 E (1978) and it was interesting to look at the differences (though subtle) between the two bikes. The F is longer but 5cm or so and this is done to a longer swingarm, which is also slightly modified. Engines are basically the same, though the plastics were very different, with the number boards moved further back from that year.
The US bikes were yellow, whilst the European ones were white and this an import (via Governor’s Bridge motocycles, where the SC500 came from).
Got the bike back and after 1 beer and 10 minutes, Gavin was on the bike and away, as it decided to fire up. Some smoke, a sticking throttle, but it went and pretty well too. The engine sounds find and not too rattly for a Yamaha.
The following morning saw me take a closer look at the bike and start to list what I need. It shouldn’t be a complex restoration but with upcoming travel and work, this is going to be the biggest restriction on getting it done. Will order all the spares I need upfront so I can work on the bike as I need to.
The bike chucked me off in the field after I didn’t take into account the slick tyre on the rear, but managed to confirm bikes going power and that is a nice riding position. One thing you notice straightaway is how light the bike is. Amazing compared to the smaller, but heavy MX and SC’s.
The list of things to do:
– strip the chassis, and clean up and paint, probably won’t shot blast but go with Hammerite Satin method
– the engine sounds good, crisp and yes it does go well. However, the problem with the engine coming out of neutral and general good practice means it’s going to be best to strip it and see what it’s like inside
– rear wheel rebuild, the rear rim is cracked along the spoke holes, which is pretty interesting.
– complete set of plastics, can be provided by DC Plastics , includes front panel and the different for that year only side panels.
– rear exhaust, silencer. The whole exhaust has taken a battering but only a rear silencer needed
– new rear wheel or rim. Hubs and wheels maybe hard to come by, but can put on an OEM or replacement rim. Back to Gerard in Caerphilly for the rebuild. Keith at Motolink has a rim.
– seat cover, MXM provide a decent one.
– tank and side panel graphics, MXM do one for the tank, but DC Plastics kit also include the ‘250’ for the side panels
– handlebars and controls. I have a new Renthal replacement for the bars, which seem to have been chopped in the past. The throttle is knackered as is the clutch lever. Will check the cables, but will get replacements from Keith at Motolink
– tyres: probably from the local L G Racing and my normal two sets of tubes
– gaskets and bearings : gaskets hopefully from Keith also, with the bearings from Simply Bearings or from my local supplier Brammer.