Monday, 14 November 2016
Honda CB400 Super Dream
The BMW R80RT had to go. It was too expensive. With the prospect of an impending mortgage, it looked like I would be going the five year old C90 route, but fortunately the ﬂat I decided to buy meant a 35 mile round trip every day, which ruled that particular descent into hell out; I decided to go for as much cc for as little money as possible. A scan through MCN revealed lots of 250 and 400 Superdreams, so I decided to go to see a few.
The ﬁrst one sounded too good to be true, A reg, 6000 mile, CB400NC model which was the last one with ﬂash gold wheels and fork legs, as well as a direct oil feed to the top end (earlier models tended to gum up their small oil ways, running the top end dry) for £500ono, which was more than I wanted to pay, but sounded like a bargain. I reasoned that if I bought it, I could always flog it later at a profit.
I wish the owner had been more honest with me over the phone, the whole thing was covered in crud, and it looked like it had never been cleaned in its life. Salt had eaten into all the casings and there was rust everywhere.
After travelling 100 miles to see it I thought I ought to take it for a run. I noticed that the speedo only went up to 100 not the CB400’s 110mph, but the owner insisted that it was original. It certainly went like the 400 but the rev counter only read 4000rpm at 80mph. When I pointed this out to the owner he suddenly recalled that it had been stuffed into a car at one stage and the clocks were replaced and there was at least 12000 miles on the old speedo...
The next 400 Superdream was in a little village just south of Crawley in Sussex. A W reg 400NA with a very loud 2 into 1, a small fairing and 22000 miles. I rode it, liked it, haggled, money changed hands (£325 with a pair of Krausers) and that was it. The BMW sold for 1500 quid, and suddenly I had a 400 Superdream and a mortgage.
The tyres both needed replacing more or less immediately. A ring round the discount tyre garages scored a pair of new style Avon Roadrunners for sixty quid including ﬁtting to the rims of removed wheels. The front wheel was fun to remove with a brake caliper either side. You have the option of removing one of the calipers or forcing the wheel between them and hoping that the calipers won't snap off. The pads keep falling out of the caliper when you try to put the wheel back in, so I rammed a screwdriver between each set of pads.
I gave it an oil and filter change, and I thought I had myself quite a nice bike. It went very well, the brakes were effective, the Roadrunners made it handle - who needs an overpriced, overrated, overweight, under-powered Bavarian ﬂat twin, I thought.
Petrol worked out at an uninspiring 50mpg, but it was thrashed at 60-70mph for most of its commuting time and the journey didn’t take any longer than on the BM. It was just that at the end of the journey, whereas the BM left me reasonably dry and relaxed, the Honda left me feeling as if I’d just ridden to Cornwall and back. The handlebar fairing kept a bit of the wind and rain away, but any precipitation swiftly resulted in wet clothing, due to my porous Kett oversuit.
I kept meaning to turn the thing inside out because I think they had the material the wrong way round when they made the thing. They’re supposed to let air and moisture out and stop water coming in. Mine let water in and kept it there very efficiently once inside.
Say what you will about BM’s being expensive, overpriced yuppie toys, but they don’t half know how to make fairings. I could almost forgive it the other sins just because that fairing made it such a good all weather bike. At least the Honda was proving a lot cheaper to run, so this made up for its deficiencies in the rideability stakes.
My smugness was short lived when it developed an oil leak from the base gasket which turned into a flood. The day it used nearly a litre of oil for the journey to work, I figured something was wrong. It took an hour to remove the engine with the aid of a friend. Removal of the tappet cover revealed a camchain that could be picked off the sprocket - not good.
A new camchain and gasket set were purchased. The camshaft sprocket bolts had to be chiselled off. The engine was stripped down to the crankcase, turned over and split, the crank pulled out and the new camchain fitted. A blob of Hylomar was used on the gaskets (as used and approved by Rolls Royce, no less) on reassembly.
Things went wrong when the engine bolts started stripping themselves - three bolts out, so no chance of bodging it. I rang the local engineering ﬁrms and found the cheapest place for helicoiling, four notes a helicoil. Threw the engine back together and rode off to work - great, we’d done it. I looked down at my leg to see my boots covered in oil again. Jesus Christ — now what?
I didn't relish the prospect of another strip down, and the oil consumption wasn’t quite as frightening as before, only about a litre for every 100 miles.
I went up to a Honda dealer in Staines to buy a new drive chain and just happened to mention the re-occurring oil problem and that I wasn’t looking forward to stripping it down again. One of the guys there looked up and asked about engine bolts - there are two bolts with rubber seals that correspond to cutouts in the casing. I’d put them back in the wrong holes. Swapped over the seals and there was a drastic improvement in oil tightness.
Anyone who’s ever experienced the Honda camchain syndrome (which probably applies to 90% of anyone who’s ever owned a Honda) should not be afraid of tackling this job. I was very unsure, but with a mate who knows a bit about bikes and my own limited experience we did it and only spent sixty quid in total, including the cost of helicoiling.
The camchain should be tensioned every 2000 miles to be on the safe side. The only way to make sure that the tensioner blade has actually moved is to take the rocker box cover off and just push the thing downwards to free it, cos they do stick and we all know what happens to Honda camchains if they don’t get tensioned, don’t we, children?
The engineer who did the helicoiling had a few words to say about anyone who designs an alloy crankcase without helicoils with high tensile steel bolts running into it. I cheered him up even more by showing him how the camshaft ran direct in the alloy head - he reckoned it wouldn’t last more than 10000 miles and was surprised to learn that the bike had already done 27500 miles.
Since this little episode the bike has run okay. The engine sounds as sweet as a nut and performs better than it did before. Crud in the petrol tank works its way through to the carbs, calling for an occasional carb strip down but this is good clean fun. The seam at the back of the tank went, a common problem and used examples should be examined carefully, one breaker tried to palm off a bad one on me.
In the past 6000 miles since the rebuild it’s been very reliable. The tyres have lots of life which is a surprise as it’s thrashed everyday. The rear Roadrunner doesn't have a groove running. around the centre, just bits of groove on either side — it grips the road well and the bike handles very precisely.
Just recently another mishap occurred when riding home in the dark. The headlamp became dimmer and dimmer, not what you need on an unlit icy road. This was traced to a perished wire under the left side panel. There seem to be a lot of wires there which are ideally situated to pick up all the crud.
I will probably sell it soon because I want something a little quicker that has more power below 6000rpm. Anyway, with all my UMG royalties which are bound to roll in I shall doubtless be in a position to go out and buy a Ducati Paso or something!