BODGING BY PREVIOUS OWNER

I had accepted that my 1975 ST70 was in quite a poor state mechanically as although it ran ok when I bought it, when giving it a service I discovered that there was all sorts of rubbish in the bottom of the crank-case (swarf, remains of a roller etc) and a complete engine rebuild has followed which should have brought it up to 'as-new' spec and make it run like a sewing machine when it has been run-in.

What really anoyed me was last weekend when I was servicing the recently aquired 1989 ST50 Dax which I am about to pass onto my father, I found that the intermitant problems with the carb were due to the previous owner assembling it with silicon instead of the correct rubber O-rings. The silicon had spread when it was all bolted together and bits of silicon were sticking out everywhere, I am amazed it had run so well up to now!
I understand that these bike cover very little mileage and the carbs tend to gunge up which means they have to be stripped & cleaned from time to time but surely if you are stripping a carb you have the new O-rings & seals to hand before you start work don't you and if you don't, you order them and fit them a couple of days later?

Anway, rant over and I hope to get it on the road again in a couple of days.


Tip. If you don't use the bike very often then drain the fuel from the carb and dispose of it rather than letting it sit there, also Redex petrol additive is a good idea as that will help to keep the fuel system clean.

I bet it's something like this? (blue 'silicon')

It's used fairly often and it is handy stuff, if used right.
Heat, oil,... resistant. But a real pain if used in too large quantities (such as with your carb) offering a lot of cleaning time for the next owner

I have to dissagree with you about the mileage.
When good taken care of, these bikes just keep on rolling.
My previous ST50 had 33.000km (over 20.000 miles) on it and still looked and ran like new.
A Honda 4-stroke engine really is bullet proof!

No, this wasn't a liquid gasket like Hermitite but really was clear silicon (as used in DIY applications) put on in vast quantiies that just oozed out in all directions when the parts were bolted together! It was the bits that stuck out from the joints that were causing the problems.

I agree that the engine is bullet proof.
When I was 16 and had my SS50 (complete with 70 head & barrel) I covered nearly 20K miles in the first year of riding alone and the bike (bought new in 1976 and still in the family) is still in tip-top condition. I hope that my newly rebuilt ST70 engine will now outlast me as I have rebuilt it using many new genuine parts (money no object) and correctly maintaned it should go on for ever (regular oil changes are the most important). It was neglect by the previous owner(s) that took it to the state it was in yet it still ran very well which is a testomony to the ruggedness of the design.
It is when they AREN'T in regular use that the fuel goes stale and should be drained off as it leads to a buld-up of gunge in the carb. If you are using it daily/weekly then there will be no problem but if you lay the bike up all winter and then just cover a couple of hundred miles each summer then you need to keep an eye on the petrol. Unleaded seems to be more prone to this than the old leaded stuff.

New seal kit arrived from David Silver today. Carb & manifold assembled with no need for any type of instant gasket and it all works very well, it is running a lot better than it had been.
The old fuel which I drained out of the tank was thrown away as it was very cloudy, it really isn't worth using stuff in that condition.

Glad you have got it sorted. Was tempted to order that carb rebuild kit for mine but I am going to try the cheaper methods of fixing it first!

Got a load of parts on back order with David Silver Spares at the moment including a couple of gaskets in the hope it will sort my air leak.

David Silver have had an item on back-order for a couple of weeks now (L/H switch assy for the Dax) and they say Honda can't deliver until July. Up until now they have always delivered within the week even if the bits had to be ordered in so hopefully this is a one-off.