Monday, January 8, 2018

CB450, CB500 Twin - Mikuni Carburetor Conversion

If you've ever had issues with your CB450/500 stock Keihin carburetors, you might want to consider this conversion. We've found the Keihin carbs from these bikes to be amongst the most difficult to get tuned correctly, especially on the CB500T with its additional circuits for the air cutoff valve, for which the rubber parts are extremely difficult to find.

Our frustrations with this led to a little experiment in which we replaced the stock carburetors with a set of Mikuni VM32 carburetors, as shown below:

You have probably heard of the Mikuni VM32 carburetor - it's a classic model used on a wide variety of small engines, and really popular for racing. It's extremely tuneable with a huge variety of adjustable needles, jets, etc, all of which are widely available.

Mikuni made many different variations on this carburetor for different applications. You may not have noticed, but there is something special about the ones we used. These were originally meant for 2-stroke snowmobiles and have small oil injection ports near the intake flange of each carburetor. We were able to convert these to be vacuum lines that can be used to synchronize the carburetors, which is very useful on any bike that doesn't have separate vacuum ports on the motor or intake manifold itself (think CB350, although you probably want to use a VM30 for the smaller motor).

The carburetor intake boots do need to be replaced to accomodate the Mikuni, but we were able to create a setup for the air boots that allowed us to use the original airbox. You will definitely want to experiment with the jet and needle sizes to get the correct fuel mixture at all throttle positions for your bike.

The only other real issue is that the choke levers, idle and mixture adjustment screws are usually "left-sided," so the right carburetor will be difficult to adjust. Right-sided carburetors exist, but are hard to find. However, there are different choke setups that can be installed, so once the initial carburetor setup is done, you can use the choke without much issue.

Also, we can do all this work for you if you're interested, just get in touch!

Wednesday, April 26, 2017

New Sign and a New Bike

We finally got a sign after 5 years in business, courtesy of Britt Lawson, who freehand drew the letters and then cut 3/16" plywood out with a scrollsaw. So now you can find us easier when cruising down Forbes Avenue. Thanks Britt!

In front of our new sign is our newest bike, a 1967 Suzuki K15P, also known as the "Hillbilly" - a street/trail that was their rival to the hugely popular Honda CT90. The big difference is that this one is 80cc and a two-stroke, and has two different sprockets in the back, the idea being that you could have one chain on the small sprocket for street riding, and then swap it out for a longer chain on the rear sprocket for trail riding. It's a super fun little ripper, with supposedly a top speed of 55. And of course, it's for sale. So get in touch if it strikes your fancy.

Sunday, January 1, 2017

Hawking our wares on the world's biggest (and baddest) online marketplace

Ben, who setup our Instagram, has also been taking photos for our new ebay store, which you can find here:

Honestly, Ebay are a pretty awful company - but they're the only game in town when it comes to selling used parts online, and they know it. So, it looks like they'll be taking at least a 10% cut of anything we sell on their site...then Paypal gets their cut, but at least we can feel good that we're helping to keep the Post Office in business.

The good news is that starting our ebay store has also forced us to organize the chaos that was our inventory of used parts. Now we actually kinda know what we have in all these boxes! So, if you see something you like, get in touch through phone or email for better prices! Cut out the middleman!


Tuesday, December 27, 2016

Look at the pretty pictures

Check it out, we now have an Instagram account for your viewing enjoyment! You can look at all the pretty pictures here:

A photo posted by SlagheapCycles (@slagheapcycles) on

Big thanks to Ben Filio for getting this all together!


Wednesday, August 3, 2016

Time to go ULTRA

We've acquired some new equipment in the shop - an industrial ultrasonic cleaner for cleaning carburetors and other small parts. Ultrasonic cleaners use high frequency sound waves to generate microscopic bubbles in a water bath solution (it's called cavitation), and these scour the grime and dirt off, leaving clean metal behind. They are great for unclogging all the tiny holes and passageways in motorcycle carburetors.
The tricky part is finding an ultrasonic cleaner that is both tuned to the correct frequency (most are for jewelry, so their frequency is too high for industrial cleaning) and put out enough amperage to be effective (most are too weak). We were lucky to find one that meets both these requirements. Here are some of our early results:

AFTER      -    BEFORE


In addition to our normal carburetor cleaning services, we will be offering the option of running your carburetor (or any other parts) through our ultrasonic cleaner. It's a good option if you want to do most of the work yourself, but also want to make sure that everything is actually clean, and all passageways are clear. We will run each carb through the cleaner, and any small parts you want to remove beforehand (such as jets, emulsion tubes, mixture screws) can be run in a separate basket. We will then blow everything out with compressed air afterwards to ensure it is clean and clear. Get in touch for pricing, thanks!

Sunday, May 22, 2016

Pre-Summer Vacation

Attention Friends! With summer rapidly approaching, we are going to sneak in a little vacation before the height of riding season, so that we can be ready for you once it finally stops raining in Pittsburgh! The shop will be closed from Monday, May 23rd until Thursday, June 2nd. We will be back wrenching on Friday, June 3rd. Feel free to email us in the meantime to schedule an appointment for our return. Thanks!

Our new garage, where all the magic happens!

Wednesday, March 9, 2016

New Location, Open For Business

After a winter of epic moving, we are all setup in our new location. And we've already managed to fill every available space with motorcycles! The shop is at 2123 Forbes Avenue, in the Uptown neighborhood of Pittsburgh. We're easy to reach from Oakland, Southside, and Downtown Pittsburgh, and blocks away from the Boulevard of the Allies. We are also easy to reach by bus (especially nice for dropping off and picking up your bike) - all the 61 and 71 buses go within a block of our shop. So, we hope to see you as the weather gets warmer!

The entrance at 2123 Forbes Avenue - here is where you drop off and pickup your bike

Inside our new work area - already overflowing with projects!