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At this point, it’s time to start installing parts. First the MLM intake elbow goes on, then the carb. Because the carb is moved away from the petcock, a slightly longer fuel line is needed to feed the new carb. We still had some leftover line leftover from when we replaced all of the oil and fuel lines in Part 1, and we just happened to have a scrap that was the perfect length.
Here you can see how the fuel lines route. The MLM intake was a perfect fit and made installing this carb a breeze, only requiring minimal modifications to fit.
With everything else installed, we cap it off with our sweet new air filter. You can see that the choke lever is within easy reach for when we fire and warm up the bike. If we were really clever, we could probably modify this system to work with the handlebar lever, but that seems like a lot of work for little benefit.
Unrelated to the carb install, we also replaced our fuel cap and oil cap seal. Both caps are three parts, with a cap, a seal (with a breather hole in the middle) and a PCV flapper. The oil cap’s seal was hard and dry rotted, while the gas cap didn’t even have a seal! In fact we were unable to fill our gas tank more than half full without having most of it splash out the vent hole as we were riding. Treatland sells NOS Suzuki gas and oil caps, so we went ahead and replaced them both.
After making sure everything was tight, we turned the mixture screw all the way in, then back it out a single turn to set our baseline fuel. Then we primed the carb and fired up the bike. After adjusting the idle and letting it warm up, we went for a short ride to finalize the mixture. Our first guess was way too rich and we ended up turning the mixture screw almost all the way back in! Turns out this carb really is way too big for our engine as it sits. We could jet down, but there really isn’t much of a point as the engine isn’t staying together too much longer.
We’ve lost a noticeable amount of low end power, though once the engine gets some air moving through it, we did pick up a bit of torque and a little top speed as well. On its own, this carb really isn’t an improvement, but it does give us confidence that we will not have any air or fuel flow problems when we bump the compression, port the cylinder runners, and add a real pulse scavenging exhaust. Also check out the sweet MLM front luggage rack we also picked up from Treatland and threw on over the summer.
With the intake side of our little moped more or less sorted out, we will turn our attention to pulling out and rebuilding the engine and final drive. Our plan is to keep the motor 50cc, but to massage it here and there to get some more acceleration and top end speed out of our 36 year old Suzuki. Since we bought it in the October of 2015, old mopeds are starting to become cool again and companies like MLM have started coming out with new parts to both maintain and upgrade old bikes like these. That gives us great hope we can keep this little Suzuki riding for many more years to come.
Footnote: If you’re wondering what the hell a minibear is, it’s an inside joke from Boy Scouts. The chipmunks of Philmont Scout Ranch are known for their tenacity and speed, so much so, that the Rangers call them ‘chipmunks with turbochargers.’ So yes, we did make a dad joke out a crummy Boy Scout joke.
3 comments
Any updates on this lil fella? I just picked one up for free.
Chapel,
It’s still in my garage, waiting on me to get around to do this engine rebuild. Right now it’s just way too cold to do a lot of garage work, but I do plan on rebuilding the motor sometime this year. Too many projects on the plate, but this one WILL get pushed back to the front!
I have the same bike almost to a T and was hoping you might be able to give me some tuning advice.