# '05 Grizzly 660 Problems



## Woods'nWater (Dec 11, 2011)

I have a 2005 Grizzly 660 that is having a few problems.

First, the thing sat for quite some time and was not ridden very often by the previous owner. When they tried to crank it it gave the a hard time so they removed and cleaned the carb. After putting it back together, it will crank but ONLY with FULL CHOKE. Once the choke is off, the motor instantly dies out.

I can get it running and if you keep on the gas, it runs wide open without trouble. But EVERY time I let off the throttle it starts backfiring/popping...EVERY TIME.

I have looked around and can't seem to find any solid information. I'm thinking about taking the carb off again and re-cleaning, adding fresh gas, and adjusting the fuel/air mixture screw.

Is this the right direction to go? Anyone have any ideas on what might be going on? Do I need to make any other adjustments and if so, how?

thanks for any help


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## Bossman (Dec 11, 2011)

Sounds like you have a low speed idle jet stopped up. I would soak all the jets overnight in a carp cleaner. Your needle may be bad. The fuel these days will destroy a carb when it sits. Ethanol in gas is to blame..


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## aka rotten (Dec 11, 2011)

*Re carb.*

Carb. still dirty take it back off,remove bowl and all adj screws.Keep track of how many turns you take as you take screws out.Use carb. cleaner and i use low pressure from air compresser to fist soak then blow every hole out,i also use tiny drill bits from welding tip cleaner to clean any blockages from holes where screws go.Sometimes some of the screws have holes in them also such as bowl screw,replace everything and go riding.Remember keep tract of how many turns you take while removing screw or you,ll have to hit and miss adjustments.oh yes run seafoam in your tank with gas from now on.Paul


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## Bossman (Dec 11, 2011)

your jet will screw into the air jet,long with small holes. Take a bread tie wrap & pull the plastic off it to expose the small wire, clean the air jet holes with that.


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## Woods'nWater (Dec 11, 2011)

alrighty! sounds good. Is it ok to soak overnight? If not, how long should I soak the carb, jets etc?

And, do you think this will solve the backfiring problem? It's really loud and annoying.


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## coltday (Dec 11, 2011)

Our Rhino is doing the exact same thing. It has been sitting for a few months and will only run on full choke and backfires. I haven't taken the time to take it off yet. It's a little aggravating to get to on the Rhino but I'm pretty sure it's the low speed jet. Report back on results.


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## Backlasher82 (Dec 11, 2011)

If you take the mixture screw out to clean the passage, which you should, make sure you get all of the parts out before you start cleaning.

The mixture screw has a spring on it which usually comes out with it. On top of the spring is a very tiny washer  and o-ring, those usually stay in the hole and have to be removed with a dentist pick or similar. They are extremely small and easy to lose. Sometimes the o-ring is damaged by the junk fuel we get these days. If the o-ring is missing or leaks, it will cause a lean condition and you'll never be able to get the mixture screw adjusted to run right.

Since you've already been trying different settings on the mixture screw, start out at 1.5-2 turns out from lightly seated. That should put you in the ball park and you can fine tune it from there.


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## 440Mopar (Dec 13, 2011)

trade you a carb cleaning for a decent duck hunt  ???


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## Woods'nWater (Dec 13, 2011)

OK, so I got the carb off and started cleaning. None of the jets seemed to be clogged but I sprayed the out good anyways. There was a little gummy build-up in the float bowl but that's gone now, and it wasn't much to begin with.

I did notice that the "holder" for the MAIN JET had an o-ring / rubber washer on it that just crumbled apart. Could this be a source for the problem? I can order an new o-ring online for cheap but if there is something else to blame then I would like to know.

http://www.yamahapartsnation.com/pa...TERRAIN_VEHICLE)/CARBURETOR_(YFM66FAT_-_2005)

#13 in this diagram

What do you think?


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## Woods'nWater (Dec 13, 2011)

I also keep reading about a fuel/air mixture screw. I see it in the diagrams, but can't see it on the carb. There is a large phillips-head screw on the outside of the float bowl, next to that there are two brass caps with small holes or an indention in them. Is the screw under these? If so, how do I get to it? and which one is it? Smaller or larger one.

Also, if this needs to be adjusted, why would it not be accessable?


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## Backlasher82 (Dec 14, 2011)

The mixture screw is just in front of the float bowl deep inside a round tube about 1/4" in diameter and dead center of the carb throat. If you look into the carb throat on the engine side you'll see a tiny hole that directly inline with the screw. Actually, you'll see 3? holes but you'll know the one I mean. The tube, tower, whatever you want to call it, that the mixture screw is in will be the only one on the engine side of the carb, center of the carb bore and it's about as tall as the float bowl gasket surface. 

When you look at the tube from the bottom you will either see a slotted screw deep in it, 1/2" or so, which is the mixture screw or you'll see a brass plug with a tiny hole in the middle. The EPA makes the manufacturers cover the screw to lower emissions by not being able to adjust it. 

You can remove the brass plug by drilling a 1/8" hole in it and the screw a sheet metal screw in just tight enough to hold and use vise grips on the screw to pull the plug out. Then you'll see the mixture screw.

One very serious thing I have to warn you about. When you're drilling the brass plug out, do NOT let the drill bit go deeper than 1/4"!!!!!!

Wrap a piece of tape around the bit at 1/4" so you'll know when to stop. That will drill completely through the plug and that's all you need to do. Also, turn the drill bit very, very slow. The bit will cut the brass better the slower you turn it but more importantly you can stop drilling quicker when it breaks through the plug.

I can't stress enough how important it is not to get carried away drilling the plug out. If the drill bit breaks through the plug and keeps going it will contact the mixture screw and screw it so hard into the carb body that it usually flares out the hole, flattens the mixture screw and damages the carb body beyond repair. Yep, that means you gotta buy a new carb. 

As far as the o-ring on the main jet, you can just about lay money it isn't the only o-ring that needs replacement. A carb rebuild kit will come with all the gaskets, o-rings, new jets, etc needed to rebuild it and they're pretty cheap, especially compared to buying the individual parts. Check Dennis Kirk, Rocky Mtn ATV or some of the other online sites and see if they sell an aftermarket rebuild kit for your model. Good luck


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## Woods'nWater (Dec 14, 2011)

ok.....I checked out all the other o-rings and they seemed to be just fine (only time will tell). But, do you think that the leaky o-ring could be the source of my problems (if it's the only one)?

I'd hate to get everything back together and find out that it was something else. But I guess thats how it goes with these things sometimes.


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## Backlasher82 (Dec 15, 2011)

You need to replace the bad o-ring but that won't fix your problem. 

The symptoms you're describing are most likely caused by a blockage in the idle circuit. I assume you removed the pilot jet, cleaned it and looked through it to verify the opening is clear. Take some spray carb cleaner with the plastic extension tube and stick the tube into the hole where the pilot jet goes and spray through to verify the passages in the carb are clear. 

Since somebody else has already had the carb apart, look at the parts diagram and make sure they didn't lose anything.

Cleaning carbs gummed up with the residue from the so called fuel we get these days can be frustrating. FWIW, if 440 Mopar was serious about fixing you up for a duck hunt you might want to consider it.


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## Woods'nWater (Dec 15, 2011)

Backlasher82 said:


> You need to replace the bad o-ring but that won't fix your problem.
> 
> The symptoms you're describing are most likely caused by a blockage in the idle circuit. I assume you removed the pilot jet, cleaned it and looked through it to verify the opening is clear. Take some spray carb cleaner with the plastic extension tube and stick the tube into the hole where the pilot jet goes and spray through to verify the passages in the carb are clear.
> 
> ...




Well come to find out, all the previous owner ever did was drain the float bowl and dump carb cleaner in the gas tank ! They didn't know enough to try taking the carb off and cleaning the inside.

I have removed all of the jets and sprayed everything down real good with cleaner. I've inspected all the o-rings I could find and now I'm just waiting on the new o-ring to arrive in the mail. The only thing left to do is put it all back together and try it out.

the tank is still about 1/2 full. And I have no idea how old that gas is. I'm thinking about dumping it and adding fresh, ethanol-free gas to the tank before I start it up.

And I'm also going to get some STABIL to add to the tank as well.


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## Backlasher82 (Dec 15, 2011)

Definitely drain the tank and start with fresh gas, you got the right idea with ethanol free too. I would add Sea Foam to the gas instead of Sta-Bil. Sea Foam will help clean any residue you might have missed, it's good stuff. Sta-Bil is good too for stabilizing fuel when you store it but that's about all it does, you need something to clean right now.


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## Woods'nWater (Dec 15, 2011)

Thanks for the tip, I'll get the Seafoam when I buy the gas. It's a shame when you have to plan a trip across town to buy gas that wont ruin your engine.


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## Woods'nWater (Dec 22, 2011)

Update .......

Got the replacement o-ring in the mail yesterday. I had the day off so I replaced it and made sure everything was good and clean inside the carb and put it back on.

IT WORKED! The Grizz runs great now. No need to choke for cranking, idles great and NO Backfiring. I did put SeaFoam in with the fresh gas and plan to change the oil here soon.

Thanks for all the help folks!


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## DrewDennis (Dec 26, 2011)

Use the stabil marine formula...handles the ethanol in the gas much better than stabil red.


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## Wild Turkey (Dec 27, 2011)

Not too much seafoam!!!!!!
It will eat plastic/rubber seals if too strong.


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