I own a few 440Lc sleds...1991 pantera and prowler. I also have a few spare parts too. I just finished to rebuild them and I saw that on the magneto Suzuki put a big steel weight riveted on it. Why?? Can I remove it? I have a spare one that I can send to the machine shop to remove it. I could easily remove a few pound of rotating weight strait on the crankshaft. Would I benefit from it? If yes Why did suzuki put the weight? What will happend if I remove it? Someone should be able to answer me. I just started one yesterday without the clutch and throttle response was kind of incredible with this weight off...so the idea came in my mind...

Here's a pic of it. I could remove everything and stop may at around 1/4" from the rivet that hold it to the rest. I need to keep some material to be able to screw plate for the starter rope.

When you go into an 'engine loaded' situation the added weight helps to keep the engine from bogging. Trust me, your sled will be almost unridable w/o it and most definitely no fun.

Your crank and bearings will be much happier with it. It offsets or balances the weight of the clutch helping to keep the load and shock load across the bearings the same. If wasn't there the mag side bearings would get hit or rattled harder than the pto. It also adds to the flywheel effect, not exact numbers but think of it like this, at any given rpm, like 8000, the crank is quickly speeding and slowing, like 7990 8010 7990 8010...etc because of the rise and fall of the pistons. This 10rpm "vibration" has an neg effect on parts but can;'t be eliminated, so the parts are designed tough enough to take it. If you lightened the mass (eliminating the flywheel effect) you may have 7980 8020 7980 8020 " more vibration" . This is way over simplified but you get the idea. Someone with 440 experience may be able to say what the motor can or can't take? you say you have a spare flywheel to experiment with? I suggest you have a spare crank also.

Yes I have a spare one too. But what I dont understand is that at 8000rpm everything is turning...clutch, jackshaft, tracks chaincase etc it give's a total of rotating weight that have an effect on the engine...So if I remove weight in those parts it should have the same negative effect on the engine? The engine cannot know from where the weight was took off. So why high perf sled builder and even factory try to remove weight in those parts to have less rotating weight?