Sunday 17 February 2019

The XS Triple Sidecar - new needles and a complete re-jet

The XS-Triple Sidecar is my daily mule during the cold, snowy and salty months. As such it has endured a lot this Winter and to be honest, even after more than one attempt the jetting of the flatslides still wasn't fully satisfactory.

Most importantly fuel consumption was heavy and it has stopped to idle. After doing quite a bit of research, I found out that the 6DP1-needles out of my VM38 carbs are the same length and should give me the much needed richer mid- and top-range.


Finding out  why it had decided not to idle properly anymore became rather apparent, once I took the old pilot jets out. Turns out there's two sizes of idle jets for Mikuni TM-carbs. 


It's very hard to see in the picture, but the needles (6DP1 on the left, 6DGM5 on the right) are actually quite dramatically different. From the midrange to the top, the 6DP1 is much slimmer and thus allows for more fuel and air to flow.


And that becomes VERY apparent when rejetting. Before I was running the bike on 37.5 pilots and 135 mains and it was running rich on the top, now I have upgraded to 45 pilots and 145 mains and when you read this, I will probably be trying out some 147.5s or 150ies. Suffice to say, the power available. grew in the same fashion, so I can't complain. Also the bike is a lot torquier now, which is a good thing as it is geared way too long for sidecar use from the factory. (Hint: it was never meant to pull a chair...)


Other than that, Spring will bring a new exhaust and a modified rear subframe, so I can finally swap rear tyres, without taking the exhaust off, which to be fair is a bit lame. 

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