Okay, i baught one of those 6 dollar 6" Drubro muffler extension for my sk 90. I needed about an inch to clear the muffler from the fuse. Anyway, after a long afternoon and a trip to the local hardware store i finally got it to work. I have got a few questions

1. The dimensions of the engine's exhaust port are 28mm and 9 mm. The muffler extension I have is 30mm by 8 mm. Will 1 mm thinner port make any difference.
2. I have got the cut as close as i can get without a machinist doing the job for me. There is still i very slight gap on the cut side and when i blow through the exhaust there is a slight amount of air that seeps out around the manifold. Is it necessary to fix this and if so could i get some sort of sealent to put between the gap.

Thanks
Cameron

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