Sprained ankle? Replace the engine block column

Motorcycling is dangerous. Check! Smoking is dangerous. Check! Alcohol is unhealthy. However? You die from life. The household is by far the most dangerous living environment when it comes to accidents and after every weekend the ICs are full of crashed mountain bikers.

Issues? Challenges!

And of course you can also hurt your ankle when walking your dog. Your kickstart ankle. Then you say the push button on the wheel of your daily classic, the Guzzi and you draw your plan. After all, a fresh KMZ 750 side valve block of the full 23 hp has been waiting on the workbench for transplantation in the 650 cc overhead valve combination of no less than 36 hp.

Also nice: Side flaps. Endearingly dated

With a piece of granite-hard Russian 3.75 x 19 rubber around the rim, that raw power and the unworldly couple can hardly be taken to the streets. Previous side experiences have proven that you are fast enough with 23 hp. There were always more people behind me than in front of me.

Parts and parts of parts

The IMZ/KMZ process is largely based on the interchangeability of parts (not parts of parts). A KMZ 750 side valve block from the early XNUMXs therefore simply fits an IMZ (Ural) four-speed gearbox with reverse. Although you do miss the smart halfaautomatic coupling of KMZ (Dnepr). The block mounting in the frame is unchanged between 1942 and today. And that the side flapper runs on 6V? Well: Richard Busweiler and Jan Wassenaar have everything in stock and, moreover, there are a bunch of specialists just around the corner in Germany.

Also read: The CJ 750. A takeaway Chinese. BMW´s R71 Mk III

Just improvise

The third wheel was put aside for a moment. The Ural went on the lift bridge. Refuel. Because the whole action was quite spontaneous, I was without extra hands. But with two cricks and a three-foot crowbar (who doesn't have it?), Spoon the block off the bucket. With the gearbox out, you can slide the block minus the sump pan on the lower frame tube and from there put it on the ready work girl without any effort. All without straining the sore ankle and / or back.

Thanks to the Lidl

On the workbench, the mounting studs in the side valve block were replaced by full M8 copies. The Russians had thought that the pieces that protrude from the block M8 should be fine. The fine thread should prevent loosening of the nuts. But at the Lidl they recently had sets of Nyloc locknuts. Problem solved.

Putting the best imposing lump of metal back in the frame will soon require a few extra hands. Massaging the new 6V wire harness (€ 35) in place is an easy job. But if you do your best, such a job can be done in half a day. And get there with a Honda CBX1000.

Administrative okay. A kind of

For particularly correct thinkers: The change of the engine blocks, from 650 to 750 cc has no consequences for the RDW administration and insurance. You usually get away with that if the number of cylinders continues to beat and the power is no more than 40% higher than original. Friend Nanko, who built a 1900 cc Peugeot diesel four-cylinder in his Moto Guzzi, did go to Lelystad with that construction. They were very impressed there. Rightly so.

More columns through this link.

More stories about classic engines through this link.