Hey guys i'm fairly new to the site (and riding in general) and was wondering if you could help me out, I have a 97' F3 and I was at a bike event about a month ago and they had a dyno contest for fun, anyways the dyno sheet for my bike was a little less than spectacular. Ive read that stock the bike has approx. 93 hp but my dyno sheet came out with 84-85hp. If I wanted to do some engine tuning what should I be looking for carbs? compression? possibly even air filter? etc. anything to get that hp to where it needs to be. The hardware upgrades are a d+d exhaust and stage 1 sprockets. Thanks

edit - not really looking for upgrades more of wondering what could be hindering the hp and how i can fix it

 

You might look at doing the routine maintenance first to ensure that everything can do its part properly.

Spark plugs, air filter, oil/filter, etc.

A performance air filter such as K&N or BMC can add a small amount of power but nothing noticeable on the road, you could check to make sure your carbs are sync'd and clean and running with the proper jetting (refer to spark plugs for lean/rich mixture)

Adding horsepower only goes as far as you want to spend. You can do things like big bore kits, cams, and all that.

BUT, it's not worth it.

With you being a new rider, the best thing to make your bike faster is for YOU to learn how to use up every single one of those horsepower.

Take a course, go do some track days and learn how to really push your bike. Just because your bike puts out 85hp on a dyno doesn't mean that you can keep up with it.

You're new, dont worry about having gobs of power until you know you can use it all!

Just have fun and be safe, the F3 isn't a powerhorse, it's a stepping stone to work on your skills so that you can jump on a 130hp bike with confidence.

 

im not to worried about upgrading it to get more horsepower just yet... i more want to make sure everythings in proper working condition and thought the 84-85hp could be an indicator that something was wrong or needed to be adjusted, the oil and filter have recently been replaced and i dont believe that it has been jetted, ill have to take a look at the spark plugs and air filter...any links you could recommend for spark plug/mixtures? thanks for the help

 

A loss of horsepower is expected as the bike ages, you wont retain out-of-the-crate horsepower for very long, and that horsepower is the MAX stock HP rating in perfect conditions on a dyno.

You can upgrade to irridium sparkplugs, but you check the fuel mixture by looking at the color of your spark plug electrode.

A tan coloured plug means that the engine is running normal and the air/fuel mixture is correct. This is the correct color a spark plug should be and it tells you everything is fine with the engine.

A worn out plug will have the electrode rounded out and worn down, a worn out plug requires more voltage to spark and will cause poor engine running.

If it's black and burned, it's oil fouled (commonly found on 2-strokes) It's unlikely that you will have oil fouled plugs unless your rings are hooped or there's a crack in the engine block.

A black dry fluffy coloured plug is caused by deposits from a carburetor that is running too rich (too much gas), or excessive idling on some engines. Black smoke coming from the exhaust is a sign of a rich air/fuel mixture. The rich air/fuel mixture must be repaired before installing a new spark plug. Common causes for a rich air/fuel mixture are:
[blockquote]
[blockquote]
dirty air filter.
air mixture screw or carburetor needs adjusting.
choke is sticking.
carburetor float height is out of adjustment or float is sticking open.[/blockquote][/blockquote]

 

I would do what others have said. make sure it isn't running rich or lean. Sync the carbs and check the air filter. If all that checks out and you still don't feel a difference or there isn't much of a change on the dyno, check the compression. That will tell you if there is anything wrong with the valves or piston rings. you can get a compression tester pretty cheap at any auto parts store(<$20). Just take out all the plugs, put the tester in one of the plug holes and turn turn the engine over a few times with the starter. if all the cylinders have good compression, then you know it is related to tuning, filter, plugs, timing ect. if your compression is a little low in all the cylinders, you're fine, it just means your engine is getting a little worn and may need a rebuild a little down the line. The only thing to worry about is if one cylinder has a much lower compression than the others. That most likely means you need a valve job. My money's on inproper jetting, and carb sync though. Good luck and let us know what you find out.

How many miles does the engine have on it? And do you know when the carbs were last syncronized?

 

ok so would that decrease be normal or average for a 10 year old bike?....from what i can tell it seems to be running on the rich side already, i dont have black smoke but theres black residue all along the inside of the pipe. ill check the plug and see what comes out.

the bike is approaching 19K, i do not know when it was last synched.

 

Excessive carbon buildup in the pipe could be a sign of running rich, although some is normal.

Freshening up the bike could give it some more life for sure, start with checking out your plugs and if you find that it's running lean/rich take it into a shop and have your carbs done up!

Then go to air filter, oil and filter, check out the life of your chain etc.

 

The horse power rating you quoted was from the engine and yours dyno results were from the rear wheel, that is where the difference is. But do like the other said i will help your bike run better longer.

 

ill check it out, thanks for taking the time to help