A long time since the last update. So for these past couple of months I’ve had the luxury of really just riding the Jota! This picture was taken today after a 50 mile blast to take advantage of the incredibly mild weather. The roads were a bit damp and with the rear tyre getting low I didn’t ‘test’ the handling.
There was however a purpose behind the gentle morning bimble. I rode with a friend the other day who reported some smoke out of the right hand silencer when pulling away or overtaking. No smoke on a stable throttle. Pulling the plugs confirmed this as the primary side was perfect but things got worse as we moved to the alternator. I cleaned the plugs and then took it for a bit of a blast deliberately going on the local dual carriageway so I could rev up to 7,000 rpm. The bike ran really well and inspection of the plugs seemed to say all was well. Sometime this week I’ll pull the plugs again to see if a gentle bimble brings problems – though when I pulled into the drive and revved the bike it didn’t seem to smoke.
I have a few thoughts if it is burning some oil. First off the top of the pistons are a bit wet. This was something the engine man pointed out when the twisted crank was fixed. A different set of oil rings was put into the motor and initially oil consumption seemed negligible. I’ve noticed however that now oil consumption is somewhere around a litre per 1,000 miles. Are the rings still not sealing properly? To test this I’m going to change over to Kendal oil as run in Harleys. I used to run this back in the day and the motor seemed to be happy. I’m currently running Silkolene V twin 20/50 which to my eye seems quite thin. I know it can’t be but maybe a very traditional oil might be better? I’ve also considered 500 miles on a sump of Halford’s Classic 20/50. This cheap oil is used to break in engines and maybe I need to roughen up the bores and then go back to the expensive stuff? Could all be nonsense as discussions on ‘what oil should I use’ are normally silly. When I first got the Jota in ’87 I ran Duckhams Q and it was fine…
My second thought is petrol. The smoking happened after I filled up in an Esso station I’d never used. The petrol was E5 but now I’m back to Shell Super E5 I wonder if this will make any difference? I know this is petrol and not oil but might be something in it..?
Finally have I got the beginnings of a blowing head gasket. I hope not is all I can say to this. The bike has done 3,000 miles since the twisted crank was fixed.
So putting aside oil how’s it going? It runs great and everytime I go out on it I smile. It’s a glorious thing to be out on, the noise, the power the taut handling and of course the admiring looks.
It’s heavy to wheel around and I wonder if a side stand might be a good addition. The centre stand is very easy to use but I wonder if I am going to drop it sometime as I roll it off the stand?
The Mikuni carbs’ are excellent – no snatching at any revs and at least 30% better fuel economy. The throttle still retains the original annoying ‘one and a half’ turn to get fully open. This more than anything restricts how hard you spin the bike up. I’m only running one throttle cable on the ‘push/pull’ system but I am going to see what dual cables feels like. When I first used both cables the throttle was too heavy but that might have been a routing problem. What I notice is that sometimes the throttle doesn’t fully close. It may be me being slack shutting off but let’s see. The only downside is I just have to ensure I don’t leave them on for fear of another hydraulic lock. I did leave the petrol on for 3 hours the other day and before starting removed the plugs just to be sure (petrol hadn’t leaked past). It’s inevitable this will happen sometime in the future so always pack a plug spanner hey!
The brakes and suspension are heavy and hard. With the former you have to pull the lever but they work okay despite the bike’s weight. I’m impressed that the rear works as it never did back in the day. An upgrade would be a 14mm master cylinder on the front.
The front forks are spindly things that do judder a bit at slow speed. I might have slightly warped discs but there’s no pulsing at the lever so I think it’s the forks. A winter overhaul may bring benefits. The rear Falcon shocks are excellent – tho’ I might go for stronger springs for pillion and camping duties. Overall the handling is best described as ‘taut’ but also classy. It doesn’t feel like cheap suspension even tho’ it’s dated. It’s not harsh tho’ it is firm. I prefer this to the softly sprung Honda NC I own. The thin tyres and taut handling combine to reward committed riding – lots of counter-steering and rising revs out of corners brings a lot of rewards. I’m also exploring the impact of shifting body weight and this helps. With regards tyres I’m finding the rear wears quite quickly. With 3,000 miles on the back the tread is noticeably lower and this contributes to high speed head shakes. It might make 5,000 legally but I’ll put a fresh rear on in the spring. The front goes twice as long as the rear.
So I hope I can start planning for a full 2023 of Jota adventures. I can’t see any reason why the Jota can’t be a daily rider and frankly as the curtain appears to be coming down on petrol now is the time to be riding rather than polishing these ‘classic’ bikes!