Honda-SOHC

Dom do all the jets bear the Keihin K logo?

I’m thinking someone has used a carb kit on your carbs in the past and the problem is the float needle valves and seat. A lot out there wouldn’t stop petrol flowing past if you held them against each other with your fingers. Lot of reports of the tip of the float needle being made off centre so fuel just leaks past, which would make the engine run rich as hell.

The only way to test is to remove a float bowl, turn on the petrol and use a float height setting tool set to 22mm and use that to lift the float, if the fuel stops when it reaches 22mm then it’s ok, if not then you have a problem. Container under the carb of course. I seem to recall genuine Honda float needles has rubber tips whereas copies just had steel tips. If it doesn’t stop at 22mm see if it stops at a higher setting, if it doesn’t stop at all then you need to replace that entire setup.

I think it’s there to stop the float needle falling out if the float was able to fall as far as it liked.

Thanks for the links George. Watched a couple of vids of it being done, one used soda crystals and one used stuff used in outdoor swimming pools, being in the UK we don’t have a lot of outdoor swimming pools so soda crystals it is. £2 from Tesco’s btw.

I did think something was in the water so it’s nice to see that confirmed.

Everything seems fairly straightforward, seems simple. A spray can lid seems to be a good idea to suspend the anode in. Cut a slot to clear the cap hinge hole if required.

I like this method, you can just leave it to do it’s work and it gets too all the nooks and crannies, cheap as well. I’d say use hot water initially as it would dissolve the crystals better.

Got a nice tank with some light to medium interior rust, gonna give this a go myself soon.

As you know I intended to do the 550 liners into a 500 block myself. However I also found that the recess in the surface where the top hat lip on the liner sits is different between the 500 and 550. You could either get them machined bigger or reduce the size of the lip on the 550 liner. I experimented with reducing the lip. Got a mate with a lathe to turn down a 550 liner lip to fit the 500 lip recess. Just did one liner to see if it worked. You’d also of course need to bore out the 500 block to accommodate the bigger size of the 550 liner.
I was really only doing this as I had 2 sets of 500 barrels with ruined liners but good fins etc and 2 sets of 550 barrels with good liners but masses of fin damage. After giving some liners away to help out a fellow member I ended up with one set of barrels and pistons worth trying to salvage. In the end I found a NOS set of 550 barrels in superb condition and dropped the idea for a later date.

If you find one that works fine then you can let others know what worked, what size to order or even make a few and sell them yourself. I’d use some gel type glue to bond the stuff in place and probably some super glue to join the ends so it’s got no joint to leak past.

Wouldn't you be better using a set of 550 barrels with the Yoshi pistons Bryan, the liners were thicker to start with.

May pop down there over summer with some barrels for you to do if that's ok. Will need to be same day though, pop down and pop back same day etc.

To me the K3 is Hondas attempt to merge a 500 and a 550F, try and get the best of both. However it didn't. They lost the iconic tulip bulb exhausts, that lost it the character the 500 had, the seat went way OTT in a attempt to make it more comfortable and it just looks ugly compared to either the 500 or 550F, the lights went FUGLY, way too big. In order to save on parts they nicked most of them off the 550F2, same forks, same front mudguard, same clocks, that part they got right. In order to try and get past emission restrictions they had to fit PD carbs and whilst better in some respects than before they just don't work if the bike isn't used regularly, way to prone to blocked jets.

The rest of the bike is fine, the engines good etc. Given a choice I'd choose either the 500 or the 550F over it though.

That would be great if my name was Graham Phil but my mum called me Ken 🤣🤣🤣