A FACTORY FIT
It’s been a while since we updated our news and what we’ve been up to in the garage with our two fine looking motorcycles. First up is the ZX7-R. There has been quite a lot going on with the bike which was unfortunately almost destroyed in a big crash at Craner Curves when we attended Bemsee’s Donington Park round recently.
The big change that Ritchie wanted to test was the new – and lighter – factory clutch basket which has a direct gear drive to the oil pump. This is more reliable, as it eliminates the standard chain drive and tensioner which is prone to failure; we’ve replaced the tensioner and chain twice already.
Chain driven oil pump was ditched in favour of the gear type on the factory ZX7-R’s back in the day…
This gear new drive turns the oil pump slower reducing pressure, so we have to run a restricted feed to the cylinder head to hold the oil back to retain a decent supply of oil to the main bearings at the bottom end. Having had so many oil pressure problems in the past this was a big and nervous step for us.
We also had a few problems finding factory parts to complete the job.
When we came to fit the clutch basket we found that we needed a thinner sleeve that fits on the gearbox shaft along with the bearings. We looked everywhere, Ritchie found the right bearings that would fit, but we couldn’t find the smaller sleeve anywhere. What we had to do was take the existing standard part and reduce it in size. Trouble is, it’s hardened steel and needed to ground down to size.
A perfectly reground sleeve and SKF bearings complete the clutch assembly…
We found a local engineering company – Holman Engineering in Byfleet – that had the right grinding machine to do the job. I really don’t know what we’d do without these small independent engineering companies. We use three of them now, the other two are Cranford Engineering and Roland Alsop; they are always there to help with good advice and are such great guys.
Perfect fit, thanks to the lads at Holman Engineering…
So once the new pump and drive was installed we were able to slide the new clutch basket on to the sleeve with new SKF bearings as the Kawasaki part numbers are now discontinued. Anyhow, SKF have been making bearings since I can remember, so we knew they’d do the job just fine.
All set to go...
The last thing was to fit the new oil feed pipe with the restricted oilway. For this we had to drop the engine a bit in the frame as you can’t quite get to the 8mm bolt at the top. Once that was in place it was ready to go.
A tatty tank soon looked the part of a champ bike again…
Well the bike was looking a bit tatty so we decided to clean her up and touch up the fairing, tank and seat unit ready for its run out at Donington. And how smart it looked alongside the 10-R; two different generations of Kawasaki, but looking remarkably similar with the new yellow paint job.
Decades apart, but matching colours…
The bike ran great in qualifying, and in race 1. So, we were satisfied that the oil pressure was fine, no overheating issues either. It just looked and sounded great with Ritchie leading the race. Unfortunately, he didn’t finish the first race because we forgot to charge the battery!! Doh!... and within site of the chequered flag, it just stopped running. It was of great interest to a lot of guys in the paddock too and drew particular attention from the Bemsee Commentator who stopped by the garage for a chat about it.
Race 2 was a disaster though.
THE COST OF COLD TYRES
Some parts were only fit for the bin...
This is what happened: Ritchie started the ZX7-R and was ready to go on the final call, which he did. The reason he goes on the final call is so that he isn’t kept waiting on the grid with his tyres cooling down; this has happened a few times this season. Anyway, this time when he gets to the gate he’s told to stop and wait because he was late, even though he went on the final call… the result had him missing the warm up lap and having to start from the back.
Ok, we understand the rules, but just because someone decided he was late – when he wasn’t – was putting him and the bike at risk. Having had to sit and wait for the rest of the grid’s first warm up lap to be over, his tyres got even colder – it was quite windy too – and he had to start at the back. But it gets worse, before the first lap could be completed there’s another red-flag bringing the race to a halt. He is then told to wait after another warm-up lap to see if he can go to the front row where he should’ve been in the first place. More time lost. After getting the nod to move to the front, the race is started and off he goes, only to lose the front going down Craner Curves. He was flat out in 4th gear at over 140mph as he entered the first left hander… on the cooler left side of the tyre. He was lucky to escape unhurt.
The bike was not looking so good though. Fortunately, the wheels frame and engine were all ok…the rest of it will need to be replaced.
Back home we tallied up the damage: Akropovic exhaust end can and connector pipe. Complete fairing and seat unit, windscreen, tank and front fairing bracket. Bent rear swingarm, broken subframe, bent radiator and radiator bracket, broken clock rev counter, clip-on handlebars, brake lever and reservoir, clutch lever, reservoir and throttle assembly cables. The bill will be a big one and could have been avoided if some of the officials at the circuit could just understand the importance of starting on tyres that are warm and the dangers and cost of not doing so.
THE ZX10-R – THE HOT BIKE
It still managed a third place even though the temp gauge was well off the scale…
We’re not talking power here, in fact lack of it. The reference to hot is literally the temperature the bike was running at and It’s been getting progressively worse. At Cadwell we thought it might’ve been down to the hot weather, but when we got to the track day at Donington Park it was still running hot on a cooler day. Back home we swapped radiators and flushed the whole system out. On practice day before racing at Donington it was even worse. So, we swapped radiators back and took out the thermostat that we assumed had been removed already by the previous owner. After a chat with Nick from MSS Performance he suggested it might well be the pump impellor; they can sometimes come loose.
Well, it wasn’t that either, so when we got the bike home we decided to drop the engine out and take a look at the head gasket.
Engine out, we were ready to find out why it was getting so hot under the collar…
Sure enough, we found the smallest fault, causing leak, making the bike to suddenly shoot up to over 100 degrees after 3 laps.
We have also got, on loan, a Kawasaki radiator from Ritchie’s mate Jon Shepherd, which is known to work so we’ll be putting that on when the engine goes back in.
Next round is Brands Hatch for the final round and we hope to be running at a decent temperature for a change. The bike running so hot at Donington was clearly holding our Ritchie back. We don’t want any of that again now we’ve found out he’s second place in the championship. Congrats to Mark Bridger who is the outright winner of the MRO Powerbikes and we’ll be aiming for a good position by the time we’ve finished this years’ competition.
Let’s hope for a trouble-free weekend, but in this game, you never know… but I guess that’s what makes it so exciting.
Thanks once more to our friends for the support and our sponsors. Maxton Suspension for helping us set the ZX10-R up, Opie Oils, R&G Racing, Cradley Kawasaki, and for the ZX7-R Wiseco, KAIS and Nova Transmissions.
Bernie Thornton TEAM 71
