Running in @Clay: featuring Mr Erratic Rotax

Having had the race engine back for a couple of months and still finished running it in, we headed off to Clay on Friday for a host of reasons; primarily to get the engine run in but also to compare the engines, work on lines and test some theories regarding grip (or the lack of it at the last race day). It was nice not to be rushing around madly as we do on a race weekend and the journey down wasn’t too bad for a week day. Unfortunately, the forecast had worsened through the week and it seemed we wouldn’t get the perfect weather for getting through the list of things to do. On top of that, there were a couple of four stroke events on over the weekend so the track was much busier than I had been hoping.

The first few sessions went well enough as we worked through the mid-range of the engine revs but then we hit a snag – anything over 13.5k revs seemed to start some kind of noise that I couldn’t explain even if I thought I knew what Junior was talking about! He was sure that it was an engine problem, which is the one problem area that fills me with dread 😮 I spoke with a few people – my engine builder and the guy I bought the engine from both of whom suggested it was four-stroking. It didn’t seem like it was four stroking but I tweaked the jet settings a touch and we tried again – the problem got worse the more revs Junior gave it. I changed the carb in case it had gone bad (and in the process discovered that my carb popoff tester was faulty and I had very likely been getting my carbs rebuilt unnecessarily!) but still we had the same problem. I was about to give up and fit the other engine so that we could at least get something out of the day but it was then that my own ‘karting dad’ (figuratively speaking) asked if my axle was bent – now this struck a chord!!! We had crashed at Llandow last time out but had competed in a race after the crash without any such problem (even if we only managed 2 laps before our exhaust manifold snapped) but it wasn’t the axle I suspected, rather a bearing hanger I had bought used and fitted the night before. When attempting to refit the axle after fitting the hanger, the axle was a good few inches away from aligning with the bearing hanger on the brake side. It turned out that the bearings seemed to have suffered some damage and were out of alignment. I had removed them at home, knocked them straight and refitted the axle – seemingly without issue. I was desperate to give the engine another chance so replaced both the bearing hanger and the axle just to ensure we could prove that the engine was/was not to blame. Luckily, the problem disappeared 😀 I am still not 100% sure that it was the bearings in the hanger but the axle looks good and I’ve refitted for our next outing.

After that our day was a bit hit and miss. The rain came and went and, although Junior seemed to be enjoying the conditions following a confidence boosting wet heat at Llandow, it meant we didn’t get the consistent weather that we needed to be able to back-to-back the engines. Nor work on lines. Nor test grip theories. We also broke both our bumpers – one when a prokart ran into the back of us into The Hairpin and another time courtesy of a bloke in a Rotax who was clearly very quick but was driving  erratically and making moves as though his life depended on every corner – bear in mind that this was just a practice day! If you had asked ten bystanders to point out which of the 30 karts on track looked most like the driver was under the influence of something, I guarantee everyone would have picked the same bloke!!! I am normally a fan of having large, mixed grids but seeing this bloke push us wide and then punt a prokart into the very next corner made me go and request the sessions were divided. It didn’t rid us of Mr Erratic Rotax but it did give us enough space we could steer well clear of him. Although you will inevitably see contact in karting, I don’t normally expect it at practice days!!!

In the end, we had achieved the main goal of running in the engine. Both of my bumpers have been snapped but at least my emergency bumper retention system (some rubber hose and hose clips) proved their worth.

I’m not sure where we’ll be headed next – Junior wants to do the next round at Clay but it’s looking like a very busy weekend with three additional classes taking part and that sets off my ‘track time alert’!!! It’s likely we’ll race unless there is a chance of a repeat of the ‘slower karts starting in front of the faster karts‘ fiasco we saw earlier in the year (the last time that there was a big Formula Blue event at the track). That lead to us/me getting into all sorts of bother – I won’t be doing that again…

Cost of practice:£35 practice fee, £12 petrol, £6 fuel
Spent since last post: used bearing hangers, £30, two used carbs £70

Total spent this year: £3,657

 

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