Part 3 of Adrian’s Yamaha RD 250 F restoration

engine rebuild

Adrian from our Oakmere store’s recent blogs have been so popular that he is getting a whole guest blog to himself again this week (almost!)

If you’ve not read about Adrian’s Yamaha RD 250 F restoration project then check out part 1 and part 2.

“So the next task I thought I would undertake was the engine. The engine was a real gunky mess – thank goodness for parts washer cleaner. I soon realised the engine would need a complete strip down then rebuild. So off came the head and barrels to reveal a real sorry state of affairs!

The engine before strip down

The pistons and liners were really badly worn and were going to have to be re-bored. They went straight to the re-borers to be made to look like new again with brand new pistons. When they came back, the re-borers had done a fantastic job and had shot blasted them – which made them a perfect surface for repainting.

back from the re-borers

painting the heads

engine rebuild

These were painted with a gloss finish high-temperature paint and this was also used on the heads. Then it was time for the engine to start being put back together.

The carburettors were another story entirely. When I finally managed to strip them down I discovered they were filled with a baked brown crusty sludge. This literally took hours to remove. However, once again, thanks to the parts washer, I managed to get them back to almost new condition only having to replace one needle which had completely seized in to the main jet. Once cleaned, I checked the float levels and reassembled – ready to go back on to the barrels with some nice new cone filters attached to the back.

rebuilt carburettors

Taking the engine casings off revealed the clutch plates had crumbled miserably and were in bits all over the floor of the casings. New plates were ordered immediately. The crank seals were also going to have to be replaced so these were also ordered at the same time. In went new clutch plates, new crank seals, fresh pistons and little end bearings on newly re-bored liners and we were starting to see progress. While the engine casings were off it was an ideal opportunity to strip and respray them. This was just a case of flattening them off with wet and dry paper, getting rid of all the imperfections and chipped paint and just respraying it with again, the gloss black paint. With the head and barrels back on, the engine was starting to look like an engine again. And in to the frame it went.”

To find out what happened next make sure you check out next weeks Alex’s Blog. 

Now back to Alex and news of an amazing exclusive to J&S Accessories Ltd the brand new Bell Star Isle of Man TT motorcycle helmet – This is a limited edition helmet exclusive to us and is £399.99

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Until next time, stay safe!