Dirt Bike FAQ

There is no real way to get it quiet with out affecting your performance…You might re-pack your silencer if that has not been done..But all and all they are noise-eee..If you start pluging things up the bike wont run right…..The exhaust on 2-strokes are tuned for the motor…If you change just say the silencer from stock to a short one.. with stock pipe…You could take a 1000 rpm's off the top rev….

Just ride your bike away from hippie..ville

Go to BBRMOTORSPORTS.COM and get a Powroll Thrust Chamber and you will get the performance of a aftermarket exhaust without spending 300 bones. Then get a rev box. It will let your motor rev past the stock limit witch will give you more hp. That is a good hp gain for under a 100 bones.

If you want to spend a little more money you can have the flywheel lightened at BBR for a hundred bucks. This will let you motor rev like a 2-stroke and make it pick up RPM's fast. If you do alot of wide open riding, this is the thing to do. "This will take away some of your bottom end."

If you still want more than get a big bore kit. If you do go with the big bore kit thin you will need to go with 26mm carb. The stock carb was not made to handle a bigger bore than stock.
P.S.- It is better to buy a complete kit than have the stock cyl. bore. Watch e-bay for these items and do not buy a china knock-off.

You just did a motor job.
-Double check the valve clearence.
-Make sure the valves aren't leaking. Bring the piston to TDC of the compression stroke (both valves closed). Remove the spark plug. With a blow gun, blow air in the plug hole and listen at the air box and exhaust pipe. Any hissing and you need a valve job.
-Double check the points and timing with a timing light.
-There might be water in the gas. Water floats in gas. If it was in the carb float bowl, when you rev the motor, the water would get sucked into the jets, clog them and drop back into the float bowl.
-Drain the float bowl into a cup and see what comes out. Anything bad, drain the tank and install an inline fuel filter.
-Clean the carb and jets with carb cleaner in a spray can.
-The float level could be to low. Remove the float bowl. Hook up an auxilery fuel supply. Turn on the fuel and lift the float by hand. -The fuel should stop when the float is level with the carb/float bowl mating surface.
-Try adjusting the needle height (on the throttle slide in the carb). Adjust the circlip up or down one notch at a time.
-If you can't get it fixed from all the answers you get here, then it's time to have a mechanic look at it.

The laws are different in every state. Check this site for your state's law.

http://motorcycleinfo.calsci.com/PrintLaws.html

With a bike like the CRF150F you need to use the clutch to get the front end off the ground. On a MX bike you can just use throttle, but the 150F doesn't hit hard like an MX bike. Start by just practicing getting the front wheel up, but don't worry about keeping it there. Just practice on how much throttle you need when you dump the clutch without flipping over backwards. Try going rather slow in 2nd gear, 1st will wind out too quickly, as you're going along just pull in the clutch, give some gas and dump the clutch. Take it easy at first and keep your foot over the rear brake just in case the front gets too high. Once you master getting the front end up just work on your balance. Try to keep the bike in the lower RPM range, if the rpm's get too high the front will drop as you run out of steam.

Are your talking motorcycles or bicycles?

Hi Sk8,,,
I'm going to make a guess and assume it's a Chinese Clone of a little Honda engine.

Normally,,all those type motors are very easy to start if the engine is in Good Condition,,,or even fair condition.
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Some things that can make them hard to start.

*Low Compression.
That can be caused by several things.
You Really need to have the compression checked with a gauge to determine if it's within proper range.
Should be about 120 psi minimum.

If it's Less than that,nothing will really help much.

"Low Compression" is usually thought to mean "burned-up / wore out Engine",,,,and that's often true.
But not Necessarily.

Valve Clearance Adjustment,,and Timing Chain condition will affect it also and make the compression a bit lower.

>>>Adjust the Valves to .003"
That's Looser than recommended setting of .002".

>>>Make sure the cam chain is adjusted right.
Sometimes the adjuster "sticks" and doesnt really work right.
Also need to check the chain for wear.
Both things are easy to do.

CARBURETOR:
These things are so small even the Tiniest amount of gum/varnish/deposits will make them behave badly.
Easiest thing to do is try some Cleaner added to the Fuel tank.
Use FUEL INJECTION cleaner,,,not "carb cleaner"—it works much better.
Chevron Techron ,,or Seafoam are 2 good ones.
Don't Overdose it thinking that "more is Better".

You may ultimately have to remove the carb and take it apart to clean it.

The Intake Manifold "never" gets loose on original,genuine Hondas.
On all the Clones,,,,it's a crapshoot.
If they Do get loose the Gaskets will leak air,,and cause hard start,bad running.
Or,,if Carb has ever been removed ,,,it's tuff to get them to re-seal without using new gaskets.

Ignition System/Spark Plugs:
Most of the late model versions all have electronic ignitions.
They usually work OK,,,and are Usually NOT adjustable.
When they FAIL,,,almost always it fails like a Light Bulb.
They just Quit Working at all,,,,no mysterious misfires,,no intermittent problems that come & go.

So IF it sparks,,and eventually Runs,,,
there's 99% Odds the CDI Ignition is working OK.

Spark Plugs.
Try an NGK Iridium Plug.
DO NOT expect it to "FIX" anything,,or even Cover-Up any sort of problems elsewhere.
Make sure everything Else is in good order First.

They are NOT Magic Plugs,,,but they DO improve starting because they can fire under a much wider range of conditions,,including Weak Ignition system,,,or partially flooded,,,very cold temps,,,etc,etc

They're expensive ,$8~10.
It Wont FIX anything,,but they can definitely help

Get a Service Manual if you can.

If You cannot find one,,,early Honda 50 & 70 Manual is Close enough to give You general basics

…………………………………………………………..
You will have to register,,but You can get Free Manuals here
http://www.repairmanualclub.com/

These will help.
Remeber,,these are NOT Identical to Yours,,not even the same engines,,70's and 90's are Different.
But they can give you an idea how the things are laid out,,,and valve adjustment,timing chain stuff is basically the same.
Carb Clean/Rebuild PROCEDURE is sorta generic,,,things like that.

Consider them only HINT,CLUE,or GUIDE,,,,and NOT actual,accurate service manuals for Your bike

Honda S90-CL90-C90-CD90-CT90 Shop Manual

Honda SL70, XL70K1 Factory Shop Manual, English

Good Luck with it

Dude, it could be 200, it could be 2000….

go to your local craigslist and find one.

craigslist.com go there, then find your city, or the nearest big city…. then go to motorcycles near the middle-bottom of the page.

I ride a 175 for about 3 years when i was in high school. Beat the hell out that old bike. I pay $200 for it and got my $$$$ out of it.

It's not for the PC but look up Excitebike for the NES. You don't collect apples or anything but you can make your own levels.

If you want to play it on the PC, get an emulator. I can't recommend enough Fceu (google it). You may have to do some searching around for the .rom file but it's out there. (FYI having a rom file and emulator is illegal unless you own the original game)