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grizzly 660 air box mod questions

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13K views 19 replies 7 participants last post by  reogem  
#1 ·
I heard people talk about the air box mod you can do to a 660 to open it up a little bit, and I plan on doing the mod as described in the link below: (sue me, i know theres a very detailed version on GC somewhere but it was hard to follow, the one below made it easy to picture in my head)

I already have all of the parts to do it, just waiting on the filter in the mail.

Grizzly 660 Air Filter Mod Instructions | High Lifter Forums


My question is: will I need to re jet the carb? and where the filter slides over the intake piece, should I use some kind of silicone / glue to hold it in place? perhaps take a screw and run it through to keep it on? Im a little nervous of it bouncing around and coming off.
 
#3 ·
I'm not sure I follow, how do I set my pod? I'm not sure what that is, nor what my screen is? I was under the impression it was as simple as removing the stock filter and guide and then installing the pieces like the link I posted.

everyone in those threads seemed to be referencing 700s?
 
#7 ·
I did that mod and did not rejet. Clamp on filter stayed put fine as long as the rubber part of the filter is DRY. I had some filter oils on there and it did try to slide off.
 
#8 ·
Also, the plastic flange works ok but as you tighten the filter clamp, the flange is kinda flexible and it squeezes down too. The aluminum flange would be better but I never upgraded to it.
 
#9 ·
There is another way to get more air on a 660.
I drilled holes and called it good, with no pre-filter. There was never mud balls on the lid before the mod. and rocks don't get under the seat.
I did this 7000 miles ago and there has not been a problem and I use the stock filter. In heavy dust the filter needs service more often.
https://www.flickr.com/photos/98048924@N06/9679169975/in/album-72157634337522819/
I drilled the holes from the underside, in the corners of the gusseting.
Most are 1/2" with a couple 3/4".
You can do a few holes and add more later after a ride, until a plug check reading is what you want.
This lowers the height for water intrusion, so I carry a roll of tape when I'm heading to the creek during the run-off season. I just cover the holes and use the original snorkel.
Here at elevation the grizz was rich and the holes didn't cause a lean condition.
 
#10 ·
You don't need to rejet with this filter installation. Your only changing a filter. Not upgrading a complete intake system.

Ridgway, this mod is not really about getting more air to the 660 engine. Its more about installing a better filter design (clamp on style), to help save the engine from taking in unfiltered air.
 
#12 ·
I figger'ed opening it up a little bite was the deal.
Opening the lid let's the grizz breather more from under the seat and not mostly from under the tank cover where steam rises and gathers from water splashed on a hot exhaust.
As I haven't had unfiltered air in the engine, I threw out what has worked for me.
Anyone considering sending money for a different design needing extra parts because the plastic collapses and the new filter is not made to fit in the old hole, can pass on what I found to work.
He is concerned about it bouncing around and coming off, and since mine doesn't bounce around and hasn't come off and hasn't needed extra part, I added a choice.
 
#13 ·
Just to pass along my experience, I definitely had dust and dirt past my oem filter because it didn't seal well. My 660 burns oil so I think the damage is done to the rings. I liked the idea of the clamp on filter so I gave it a shot. Even with the plastic squeezing down, the filter stays put and seals well.
 
#14 ·
Got it done today. Didnt use the gasket material, just siliconed it. I used a cutting wheel on a die grinder and had to be careful i didnt put a hole in my air box :icon_ goofy:

but overall I was impressed with the fitment (I used the two stage Uni) in the air box and on the plastic piece. I put a groove in the plastic lip too to try and help the filter stay on though I'm not sure it will need it.
 

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#16 ·
So I did this mod about 14 months ago. I don't ride it much other than around the house and took my first decent length ride (~15 miles) in april and checked it when I got home. I found the gray plastic piece had melted and my filter was barely hanging on (BOTTOM PICTURE - sorry theyre out of order)


replaced the plastic piece and the very next ride on it probably 4 months later (around some buddys short trails) is when i noticed the bike running like shit. backfiring, not wanting to cruise at an idle speed or it would stall. I got home and noticed the plastic piece had began to melt again. i tightened it up and cleaned the carb, noticed the black plastic thing in the back of the carb had gotten hot and stuck open - so I sanded it down and cleaned everything again and it ran fine.

then it started running like garbage again and i was again trying to diagnose the backfiring and running like crap issue for awhile so I had cleaned the carb, drained the gas, etc. and found the plastic piece had stuck in the open position again. when I was running it in the yard trying to figure out the issue i apparenlty melted the air filter at some point from it backfiring??

either way i could have caught things a little sooner - but I had nothing but problems after I did this mod to my bike 0/10 would not recommend it was a giant waste of time. perhaps everything was coincidental but I had the bike for a year and did twice as much riding that first year than I did the entire time I had that slip on filter mod. cleaned everything up last fall after I found the second issue and it ran fine with a stock filter.
 

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#19 ·
You have a problem with your bike. Could be many things, but more than likely valves are tight. The airbox mod is not your problem nor will it cause a problem.

Think of it this way. There is thousands of people out there with this airbox mod (me included), who have no issues. You had yours melt and your blaming the mod? Your looking at it incorrectly.

How about we try to help you fix the underlying cause and get you back to riding with a 100% properly operating bike?
 
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#17 ·
I originally bought that plastic intake but after inspecting it I had a feeling it would distort from the hose clamp. So after much research I found a heavy duty aluminum flange for under $10 delivered and it works great for my 2016. Its under several model names but one is ebay # 310751207629. I now use a clamp-on unifilter and eliminate the dust risk with the garbage stock one.
 
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#18 · (Edited)
Nice find. This is what we want to hear. Thanks for sharing it.

I would like to add though. The plastic adapter would of worked fine. You do not need over tighten the clamp. You only need it snuggled up enough to secure the filter. That's all.