Crown and pinion gear removal 1998 yamaha grizzly

let the bear out
change the gas, check the timing

Or a drive belt assembly

Hey Ralph,
This is serious,,, You can pull the right side cover off and see if anything falls out.. SERIOUSLY... there something that is interfering with the primary gears turning.. it could be something lodged in one of the gear teeth,, one of the gear teeth is cracked/broken,,
If you are really good!! at mechanical things, and you have some special tools,,, you MIGHT be able to diagnose the problem..
BUT > I would highly recommend you taking this to a qualified professional.
Motorcycle Service and Repair Manuals

Sounds like your wet clutch is screwed not good news.

Grizzly 660 Shifting problem. - Yamaha Grizzly ATV Forum

www.grizzlycentral.com > ... > Grizzly Engine & TransmissionMar 12, 2012 - 4 posts This is a discussion on Grizzly 660 Shifting problem. within the Grizzly Engine ....2005 grizzly 660 gear position sensor problem.

From experience, its one of two things, bent or worn out shift forks or worn out engagement dogs on the gears themselves. A professional job. Does it fall out if you hold the gear shift up or down while driving? Take it to your local professional!!

If you're in to low a gear, the clutch might be slipping under stress from high revs. You might need a new clutch or stronger springs. Try using a higher gear and use 50% braking.

drian engine oil take side cover should be an 8m to 12m depending on the model... the stator might be attached to the cover or might have a mount holding it into place to the fly wheel

is the battery good .may need a new one.could be a bad spot on ring gear. let me know may be able to help you more

check fuel flow and check spark at spark plugs

According to an "ATV Rider" 2009 article, "When the Grizzly was introduced in 1998 as a 600cc machine, the top was blown right off the displacement wars of the time."
It was replaced in 2002 with Yamaha Grizzly 660, an even bigger engine derived from the well-established all-terrain vehicle (ATV) Yamaha Raptor 660R.
Grizzly's 660 cubic centimeter (cc), four-stroke, liquid-cooled single overhead camshaft, five-valve engine performs well in open country, but sometimes it causes serious problems for owners.
Before you call a Grizzly dealer, however, trying a few tricks in your garage can save you a lot of time and money.

Check the fuel level.
Locate the fuel meter indicator on top of the multifunction display.
If it does not work properly, open the fuel tank, and push the Yamaha 660 Grizzly side to side.
Ensure the fuel is not contaminated by water or rust.
If you have not driven your Grizzly 660 for a long time, drain the tank completely, and fill it with a fuel tank cleaner.

Check fuel hoses for cracks or leakage.
The hoses should be soft and simple to bend.
Replace those that show any sign of wear.

Check the compression.
Screw a compression tester into the spark plug hole, and press the electric starter button.
If no compression exists, contact a Yamaha dealer.
Wipe wet or dirty electrodes with a dry cloth.
The spark plug gap should be checked regularly

Correct the spark plug gap.
Measure the gap with a wire thickness gauge.
If necessary, adjust it to 0.8mm using a screwdriver or replace the spark plug.
Use only a Yamaha-specified spark plug.

Check the Yamaha 660 Grizzly's battery.
Operate its electric starter.
If the Grizzly starts quickly, then its battery is in good condition.
If the engine turns slowly, check the battery lead connections, and you may need to change the battery.
If the engine still does not eventually start, your Grizzly is beyond home repair.