An Anniversary, Scarlet’s Carb Is Refitted, A Battery Charged, And Lists Updated

The last week was quite a busy one, so I haven’t spent a lot of time one the bikes. Last  weekend also marked the 20th anniversary of my mother’s death on the Australia Day long weekend, so I kept myself busy attending to my house and family.

I did manage to refit Scarlet’s carburetor though! Working on a Honda CB250 RS over this particular weekend is very important to me, as mentioned a couple of times on this blog before...

I had misplaced the mounting bracket for the throttle cables last week – I found it during a shed clean-up thought, so I replaced it before mounting the carvuretor

As the weather has been quite warm in the Australian summer, I was able to maneuver the carb back into the boot with relative ease. Once this was done, I reattached the throttle cables and choke cable.

I also glued a new reel for the power cabe.onto the base of my old combination work light/extension cable I use in the shed and carport. Although the light is quite bright, these pictures were taken with the flash on so it looks less bright.

Next I put Scarlet’s battery on to charge.

I reviewed and updated the spare motor task list.

I also checked off an item on Scarlet’s task list for the first time since revising it!

Finally, I took another look at the rebuilt carburetor.

I’ll see if I can get the airbox back in and start her again this week!


A Salvaged Jet And Scarlet’s Carburetor Is Rebuilt At Last – Keihin PD70 Rebuild And Submodel Comparison

This week, I found the defunct carburetor from my CB250RS spares collection.

I salvaged the main jet from it – for reference the size is 122. The spare jets in the kit are 110 and 115, so not close enough in size for my liking.

Despite both carbs being Keihin PD70 models, there were a few noticeable differences. The shape of the air cut-off valve diaphragms was slightly different, as were the chambers for them.

The float bowls had slightly different casting numbers inside – one was 1 – 2 and the other 3 – 2.

The carburetor bodies were slightly different too, despite both being PD70 models.

The older-looking one had a fixed pilot jet.

The pilot jet in the newer-looking one was replaceable.

I also salvaged the needle jet as it was in better condition than the one from Scarlet’s carb, then reassembled the slide and throttle linkage.


After assembling the slide and throttle linkage, I replaced the main jet and pilot jet.

After installing the jets, I replaced the throttle and fast idle screw.


I replaced the top cover, using the new gasket from the kit.

I then replaced the float valve, float, retaining pin, and idle adjust screw. I replaced the spring, washer and o-ring with new ones from the kit when replacing the idle screw.

I replaced the idle cut-off valve assembly.

I then fitted the new o-rings from the kit when replacing the float bowl.

Finally I replaced the drain screw, again using the new o-ring from the kit


The carburetor is once again rebuilt at long last!


Next week, I’ll see if I can get the carburetor back into Scarlet and whether or not it makes a difference.

I Lost A Jet, So My Daughter Can’t Rebuild Scarlet’s Carburetor Yet!

Tonight, I asked my daughter to help me rebuild Scarlet’s carburetor, as her mum needed a much-deserved break. My daughter didn’t seem very impressed by the idea.

I thought maybe it would be a good time to compare the original parts with those in the Keyster XL250 carb kit I bought, to show how different they are.


Here’s the kit contents in a bit more detail.

Here’s the needle jet that was in Scarlet’s carburetor, gradually rotated to show the text stamped on it. If you can’t quite see the numbers, it says 77A.

Here’s the needle in the kit – it says D272. It’s also brass and a lot shorter!

The other jets weren’t much better, but at least I can probably use the float valve.

I was about to take a comparative photo of the main jet with the two replacements in the kit until I realised I was missing the original main jet!

My daughter and I had a look near the shed door and on the floor of the shed and found a lot of other parts for the carburetor, but not the missing jet. I put the other parts in a ziplock bag for safekeeping.

“Silly daddy, you can’t expect me to rebuild a carburetor with the wrong main jet!”

So this week was a fail, as is the carburetor until I either find the missing main jet or find time to check if the spare old carb has a main jet I can use.

Maybe I’ll manage to do that in time for next week’s post!


The End Of My Holidays, Sylvie’s First Inspection Anniversary, And A Not-So-Smart Charger

This week I gave Sylvie some attention, as I’ll have finished my holidays by the time this post is published. It will also mark the first anniversary of my post about her successful rego inspection!

As expected, the battery had no charge after not riding for nearly a month!

This of course meant that the seat came off so I could access the onboard toolkit and take off the side panel to attach the charger.

I connected my newer “smart” charger.

It turned out that the charger wasn’t smart enough to recognise a flat motorcycle battery, as the fancy electronics seemed a bit confused by the apparently totally flat battery.

So I hooked up the trusty old trickle charger.


The lights indicated that it was charging, so I left it on for about 8 hours.

It seems to have had no problem charging the battery, as when I turned on the ignition again I found everything to be working as well as ever. I started the bike and let it warm up for a while.

Despite the temperature being 39-40°C (102-104°F, for any readers not yet using metric measurements), I put on my gear and went for a ride!

I’m happy to report that apart from needing fuel, no other issues came up.

That’s all for now – I’ll see what I can work on for next week’s update!

Hazard Marking, More About My Compressor, And CB250RS Cylinder And Seized Piston Removal

Happy New Year!

I took last week and yesterday off from posting due to Christmas and New Year, but I was able to get a few things done over the holiday period.

Firstly, I got sick of hitting my head on the shed doorway, so I decided it was time to remedy the situation.

First up, here’s the doorway in question from outside and inside the shed.

I measured the height from the highest part of the threshold and found it to be exactly 170 cm

As I’m 183 cm (about 6 foot) tall, this is low enough to be a real hazard for bumping my head on. Fortunately my local hardware store sells reflective hazard marking tape. Here’s the view of the same doorway from inside and outside the shed now.

Next up, while I was using the air compressor to inflate the tyre on one of my wheelbarrows so I could do some work in the garden I decided to use the compressed air gun to clean some cobwebs out of the compressor itself. The brown acrylic paint started coming off some parts of the motor (mostly the plastic ones) but I noticed something new on the electric motor – a brand name!

A quick Google search told me that CMG is an Australian company that still makes electric motors. I haven’t had any luck identifying the motor model yet though.

Finally, I decided I was sick of working on Scarlet’s carburetor, so I decided to move onto the seized engine.

The two remaining mounting bolts for the cylinder were easy to remove.

The cylinder itself came off very easily too.

Inspecting the barrel didn’t reveal much at first glance.

Looking at the piston told another story, however!

It turned out the piston was seized to the dowel mounting it to the conrod.

As it wasn’t moving back and forth freely, there was some severe scoring on the outer side of the piston, most likely caused when the motor was turned over after it had seized.

With the piston free, I was finally able to maneuver the cam chain out.

I had another look at the inside of the cylinder and sure enough there was some nasty scoring on the outer side too, while the rear was relatively unharmed.

I removed the piston rings as best I could and cleaned the piston a little to look at the damage again

After only getting one circlip out and finding the mounting dowel to be completely immobile, I decided to use a hacksaw to crack the top of the piston open. After that, I was able to wedge a screwdriver in and split the piston completely.

I noticed some numbering “471” and “1” on the side opposite the “HON” and “DA” – this might indicate the original size or part number.

The conrod and mounting dowel seem to have seized together too. If this motor is going to run again, it’ll need a re-bore, oversized piston and most likely a new conrod as well, as I was a little overzealous with the hacksaw and left a few lines in the top of the conrod!

That’s all for now, regularly scheduled updates will return next week. The next update will most likely be an update on how Sylvie has handled not being ridden for nearly a month. I’m expecting a flat battery at the very least!