My kart transport trailer.

I kept it simple, a simple deck with a couple to blocks to position the front wheels. All the tools and spare parts go in the car... which normally is my Porsche 924S. The cart is held in place by ratchet straps. I have to make sure all the kart parts are securely attached and nothing is left laying on the trailer before setting out.

Pressure brake bleeder.

A bottle, some tubing and an inner tube valve...

Work in progress.

Ignition rotor puller.

I adapted my automotive ''Harmonic balancer puller'' for this task. The bolts with puller are not usable so I made a couple of bolts from 6mm threaded rod stock.

Wrench to hold the rotor for loosening or tightening the ignition side crankshaft bolt.

I made this tool from a 3/4 inch (inner diameter)  washer welded to a piece of steel for a handle. There are 2 holes drilled to allow it to be bolted to the rotor.

Sprocket puller.

I am still working on this. The 50$ US price of a real one has me searching for a cheap alternative. I am trying to be able to use my standard claw puller with and adaptor.

This is my first attempt, it worked on the sprocket of an Ital Sis, but on a Rotax sprocket that was really stuck the mild steel plate just bent.

 Next I tried this bearing puller... but the bevel on the puller only contacts the ends of the teeth and so all I got was a second broken tooth on the sprocket. I would have been upset if there had not been one tooth missing already.

My latest attempt is made from square tubing 1 1/2 inch square tubing, 1/8 of an inch thick. In the third picture you can see how it fits over the sprocket and how the claw puller is installed. This one seems to work, but I have still not been able to get the sprocket off the Rotax. Despite applying a lot of pressure the sprocket hasn't moved, but at least no more teeth broke off and the puller has not bent.

I am going to try heating the sprocket while the puller is pulling on it...

Piston wrist pin puller

Actually a pusher not a puller...

This is my clunky solution... I have seen much nicer metal home-made pullers but have not got around to making one because the metal work takes more time than wood work... this might be of use to someone anyway.

Here is the apparatus, the block on the left is just to guide the deep socket that is used to push the pin out. The hole in the block on the right is where the pin is pushed into. The base has 4 holes that the cylinder studs in the crankcase pass through.

Here it is placed on the crankcase with the deep socket in place. Make sure that the socket is small enough to pass through the piston hole and large enough to engage the pin. Make sure the circlip is removed on the side that the pin will exit!

Here you see the adjustable C clamp in place. To push the pin all the way out you have to add an extension to the socket once it is flush with the guide block... unless you have a very deep socket.

Before installing a piston pin place a circlip on one side... then insert the pin from the other side and push it flush with the circlip. Heat the piston and put the pin in the freezer for awhile, put some oil in the hole and it will slip right in just using hand pressure, with a socket to get it seated against the circlip, but work quickly to maintain the temperature difference... and wear gloves the piston is hot!

Crankcase compression testing.

This is pretty simple, you need to seal carb and exhaust ports then introduce compressed air into the engine and see if and where it leaks out. I put the sealed engine into a tub of water and look for bubbles. I've found leaking crankshaft seals, a bad cylinder gasket and leaking rotary valve covers.

The blanking plates are made from aluminum plate with rubber gaskets from an old inner tube.

To introduce the compressed air I first installed a bicycle tube valve JB welded into the exhaust blanking plate but found that the access was difficult if I tried to turn the engine in its bath water to see various potential leak areas. So then used the base of a spark plug with a more sophisticated bike inner tube (Presta) valve that I got for free from my local bike shop... they have lots of old tubes that they throw away. The valve is an easy fit, injected epoxy to fill the cavity between the valve and the spark plug and put a washer and nut on to hold it in place. Since I don't have a Presta air pump I added an adaptor for a regular air pump.

 

Here is a tip on how to "disassemble" an old spark plug.
https://youtu.be/ziWcLDL-g_E

Piston circlip installation tool.

Installing the circlips in pistons is one big PITA so I am very happy that I figured this one out.

A length of half-inch copper water pipe with slots cut lengthwise at one end to reduce the diameter.
File the circumference so that it will enter into the hole in the piston and a screw clip to close the slots
Next I made a plunger from a piece of steel tubing (wood would be easier...) filed and sanded to fit the interior of the copper piece.

Push the circlip into the copper tube at a 90 degree angle to how it will fit into the piston. Push it in far enough that you can turn it back 90 degrees without it popping out.

Next insert the plunger in the rear of the copper tube, push the circlip to the very lip of the copper tube so that it is ready to slip into the piston. To do this it is necessary to place the copper tube front end down on a hard surface, with a good deal of pressure, while pushing the plunger down.

When the circlip is properly placed place the tool vis-a-vis the piston's wrist pin hole, press it into the hole as tightly as possible and press the plunger again to pop the circlip into the piston.

It may not work the first time, but after a couple of tries it will be in there. You will have to nudge it into the groove using the plunger or a small screw driver.

(I may make a video at some time...)

A sprocket wrench to hold the sprocket while loosening the drive side crankshaft bolt

Here is my sprocket wrench, made from a length of square tubing, a chain and an old wrist pin.
To get the right fit you can play with the length of the tubing, the length of the chain and the diameter of the "pin" (use a piece of wooden dowel?). This one cost me nothing because I had everything lying around... I didn't even have to cut the tubing, what I had was just about the right length. It is a bit loose in the pictures, but it worked like that. I used an old wrist pin with some tape wrapped around it to block the chain at the other end of the tube... I should try something a bit larger to tighten it up.

The engine in the picture is a JICA engine with a clutch, the sprocket wrench would be of no use on it... but it was the only engine in the house with a sprocket on it...

Help with installing crankshaft seals without disassembly of the crankcase.

I acquired a third CRG S30 T1 JICA engine and a leak test revealed a leaking seal. 

Removal

Since the clutch was off access to the seal was easy though removing it was tricky. I tried screwing in small self tapping screws, but the outside of the seals is metal, so I drilled 2 small holes to start the screws and was able to pull the seal out. The problem was there were some small pieces of metal from the drilling that fell in on the bearing, I hope I got them all out using my Shop-Vac. Next time I will try something else, like a small screw driver, being careful to not scratch the crankshaft or the casings.

Installation

I thought that I could use a deep socked, 7/8'' or larger, but the crankshaft is too long on the JICA engine because of the clutch. So looking around the house and garage I came up an oil pump sleeve from my Porsche 924S. Just the right size to extend the socket and tap the seal into place. Another possibility is an old crankshaft bearing, which would be more common than old Porsche parts in a kart owner's garage.

Introduction and explanation

In 2014 I pulled my old Tony Kart out of the back of the garage where it had been languishing for 14 years with the intention of doing some lapping. I got it running and promptly blew the CRG JICA engine first time out.

With no budget to pay someone else to repair the engine I have had to figure it out myself, thus started the process of learning to repair and rebuild 100cc kart engines. They are very simple so with a bit of practice you can do a complete overhaul with basic knowledge and tools.

An ad I put online for spare parts got a response from Robert who had 5 engines (that later became 7) that needed work.

Since than I have been working on and learning about these engines, so far I have done partial or full rebuilds on these engines.
my original CRG JICA (hone, piston and rings)
3 Yamaha KT100s (one took a hone, piston and rings, crankcase seals and crankshaft bearings)
a Titan JICA (hone, piston and rings, crankcase seals and crankshaft bearings)
2  Vortex JICAs
2 Ital Sis MV21 ICA rotary valve engines (both needed, a hone plus piston and rings)
Rotax DSB ICA rotary valve engine (compression test - leaking seal on the rotary cover)

I have come up with some tricks and home made tools that I would like to share. If others can add their tips and tools contact me and I will add them to the blog.

I have been following this Facebook page...

Proper Karting - Formula 100cc - Rye House - Hoddesdon Kart Club

... which has taught me a huge amount about 100cc 2-stroke kart engines in general and specifically on the engines from the 1990s that make up my collection. I like the simplicity of the air-cooled engines and during the '90s they reached the high point of their development.The above site gives one access to a lot expertise; most of my questions (sometimes dumb) have been answered there.

Also I have the following very useful books:
"The Complete Yamaha KT100" - by Jean L. Genibrel
"Le guide technique du kart - moteurs de kart 2000" - by J.P. Mechin

The blog is very much a work in progress... I start pages before having pictures to finish them, just so I won't forget. I will work at getting them all completed eventually.