The motor has a rattle when first cranked...after 10 minutes its not as loud...above 1500 rpms you cannot hear it... bike has 33,000 miles on it and is completely stock from factory... is it time for a rebuild?thanks for any help... I also have a rattle - 1993 CBR 100F. Really bad when cold, but nearly always around, sometimes quiet, sometimes loud. Often gets quieter when I put it onto side stand. I paid for a new oil pump chain and it was great for about 1 month - now back again with a vengance! It is in the workshop as we speak (different from last time!), so I will let you know what they say it is. Daniel

It does not matter how many RPM is needed. You must consider only the time required to lift the weight, the distance to raise it, and the horsepower needed to do the lifting. One HP can lift 33,000 pounds one foot in one minute. or 1 pound could be lifted 33,000 feet in one minute or any combination that multiplies to 33,000 pounds x feet.
So for 200 pounds, 1 HP could lift it 165 feet in one minute. Should we use a smaller motor of 1/10 HP it would lift the 200 pounds 16.5 feet in the same minute. The other useful thing to consider is the equivalent wattage needed for the electrical power supply. One HP is about 745 Watts. So the power to run your incandescent 75W light bulb would be 1/10 HP.
Note: RPM is not significant.

Where is the noise coming from?!?!?!?!?!!?!!?!?

Hi Lucas, What engine is fitted? If the engine is petrol, the rattling sound you have heard could well be an effect named 'pinking.' Its usually caused by the ignition timing being out of adjustment and related to the octane rating of the fuel. The ignition timing is set with a stroboscopic timing light. the ignition timing is set at 10 degrees before top dead center. Regards John

Depend on the model bike you have. This is not uncommon especially if you have one of the Dresser models. You can try to locate the source of the rattle and try to remedy it but nearly all H-D bikes do this. My Dyna Wide Glide does it and there just seems to be nothing there that should rattle.

Steve

the rattle may just be vibration or a failin bearing-old bike--carb shud be takin apart-cleaned-and ajusted if problems get worse--buy a repair manual thats what the pros use

your exhaust pipe is rattleing near or at the convertor

well if it is the engine i am thinking of that has the small ac belt with the little tensioner on the passenger side bottom area it is most likely the ac clutch is locking up turn the rear air of have some one rev the motor watch the tensioner if it is moving alot banging into another part making the rattle then you might get ready to have to replace the compressor when it gets worse they usually break the tensioner.

clean the carburator and the air cleaner also clean your spark plug or instead replaced it with new one. denso irridium would be the best for it.

That is a typical sound on any 1987 CBR1000f. It stems from the cam chain slaping inside the case. An adjustment can make the sound go away for a few thousand miles, however it will inevitably come back. If its realy bad (aka, doesnt go away over 1700 RPM) then you should probably adjust. Typicaly there is no problem, and just let the bike warm up and the oil pump all the way arround before wraping it up. Hopes this helps.

Is it a 3.9? Does it sound like it is coming from the front of the engine(timing chain)? From the factory the 3.9 didn't come with a timing chain tensioner. They are available after market.