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Discussion Starter · #181 · (Edited)
Yeah, im still workin on it. I chatted with Arnie about what to expect and he said unfortunatly no amount of sheave work will get my Kodiak to even feel stock let alone more than stock once I put decent mud tires on it (i was thinking maybe 28 aztex at 35lbs each)
This is one of the things i learned... The stock Grizzly / Kodiak have a specific internal gear ratio that is fixed inside the mechanical transmission that we cant change. When going to a bigger diameter tire you are effectively gearing the ATV up for more MPH and the engine does not produce the power it needs for that big of gear change. Machining the sheaves will help some but typically you wont bring the gear ratio back close enough to regain stock performance. There is somethings you can do to get the performance back though. Stiffer secondary springs will help a ton in the lower clutch ratio's. I tried that when I went to the PitBull's and before I decided on squaring up my tires. I went from a EPI purple to a EPI Gold and i loved the way my Grizzly accelerated up to 40-45MPH. After the 40-45MPH it fell flat on its face IMO. So what else can be done?? I will let you know what I tried and it works but it will cost you MPG's. I went back to the EPI purple and went to 16.5g clutch weights. My performance was back from the hit of the throttle all way through top end at the expense of not being to go more than 60 - 65 miles on a tank full of gas. Depending on how you are going to use your ATV this might not be a deal breaker??

For me it was Not as a lot of times we run between 85-95 miles before we can get gas again. Stiffer secondary springs will slow the clutch shift out point. This helps with throttle response and acceleration but usually at the cost of top end. Lighter clutch weights let the engine rev up faster and could over rev. A slightly heavier than stock secondary spring and lighter clutch weights will get your performance back but at the cost of MPG. Getting your clutching exactly the way you want it can be done though, It will take some time and money for parts to play with. It will take a 2 to 3 secondary springs and 2, 3, maybe 4 sets of clutch weights. Getting you clutchs to the 90% of the way you want it takes time. Getting it to 100% the way you want it turns into work as it takes a lot of time as you have to test each set up in real world conditions. All of this and you end up with 30-40% less MPG. So the choice is yours.

IMO the 1st thing I would do is get your machined sheave and slap in a EPI secondary spring and go ride it. Then make your evaluation if you are happy with the performance or not. If not you now have a better understanding of what it takes to get it there.
 
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Yeah, im still workin on it. I chatted with Arnie about what to expect and he said unfortunatly no amount of sheave work will get my Kodiak to even feel stock let alone more than stock once I put decent mud tires on it (i was thinking maybe 28 aztex at 35lbs each)
You can have your cake and eat it too. Well almost. You can achieve almost stock performance with big 28" mud tires, but you have to choose your tires wisely. Weight is the biggest killer, not the OD. The problem is, the majority of the weight of a big lug mud tire is out at the outer diameter... The spot where that weight is felt most on the drivetrain.

The key is choosing a decent tread pattern in a lighter weight tire with slightly smaller lugs. Often just being able to turn the smaller lug tire with more available speed and power will out perform the bigger lug mud tires in the same situation.

It's just like ZRT said about the clutching, ya gotta choose the parts wisely and sometimes a bit of experimenting is needed.

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This is one of the things i learned... The stock Grizzly / Kodiak have a specific internal gear ratio that is fixed inside the mechanical transmission that we cant change. When going to a bigger diameter tire you are effectively gearing the ATV up for more MPH and the engine does not produce the power it needs for that big of gear change. Machining the sheaves will help some but typically you wont bring the gear ratio back close enough to regain stock performance. There is somethings you can do to get the performance back though. Stiffer secondary springs will help a ton in the lower clutch ratio's. I tried that when I went to the PitBull's and before I decided on squaring up my tires. I went from a EPI purple to a EPI Gold and i loved the way my Grizzly accelerated up to 40-45MPH. After the 40-45MPH it fell flat on its face IMO. So what else can be done?? I will let you know what I tried and it works but it will cost you MPG's. I went back to the EPI purple and went to 16.5g clutch weights. My performance was back from the hit of the throttle all way through top end at the expense of not being to go more than 60 - 65 miles on a tank full of gas. Depending on how you are going to use your ATV this might not be a deal breaker??

For me it was as a lot of times we run between 85-95 miles before we can get gas again. Stiffer secondary springs will slow the clutch shift out point. This helps with throttle response and acceleration but usually at the cost of top end. Lighter clutch weights let the engine rev up faster and could over rev. A slightly heavier than stock secondary spring and lighter clutch weights will get your performance back but at the cost of MPG. Getting your clutching exactly the way you want it can be done though, It will take some time and money for parts to play with. It will take a 2 to 3 secondary springs and 2, 3, maybe 4 sets of clutch weights. Getting you clutchs to the 90% of the way you want it takes time. Getting it to 100% the way you want it turns into work as it takes a lot of time as you have to test each set up in real world conditions. All of this and you end up with 30-40% less MPG. So the choice is yours.

IMO the 1st thing I would do is get your machined sheave and slap in a EPI secondary spring and go ride it. Then make your evaluation if you are happy with the performance or not. If not you now have a better understanding of what it takes to get it there.
My issue is ive never ridden a 700 or an XMR (my first choice but all the memes of constantly breaking scares me) and im having buyers remorse already even though all I did was put down a refundable deposit. I know the yami wont have the performance of a v twin. All i can do is watch vids and try to gauge. There is a chance i can do all the clutch stuff and put on 28 Aztex and be perfectly fine with the power launching into holes or rippin down the trails at a nice cruising pace.
 

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Discussion Starter · #184 ·
You can have your cake and eat it too. Well almost. You can achieve almost stock performance with big 28" mud tires, but you have to choose your tires wisely. Weight is the biggest killer, not the OD. The problem is, the majority of the weight of a big lug mud tire is out at the outer diameter... The spot where that weight is felt most on the drivetrain.

The key is choosing a decent tread pattern in a lighter weight tire with slightly smaller lugs. Often just being able to turn the smaller lug tire with more available speed and power will out perform the bigger lug mud tires in the same situation.

It's just like ZRT said about the clutching, ya gotta choose the parts wisely and sometimes a bit of experimenting is needed.

Sent from my Pixel 5 using Tapatalk
Make up your mind. Is the Weight or the OD?? LOL. I get what you are trying to say though. Most of the weight of a big mud tire is closer to the outer OD of the tire. When I first switched to 26.5 Pitbull's I didn't know if it was the weight or the OD that really killed the performance. Then I squared up the tire's and got back some of the performance. When I squared up the tires I took off like 30 lb of rotating weight. So weight is part of the equation but OD play's a big role as well. Weight rob's HP and OD of the tire changes the gear ratio. The 16-18 are geared up VS 14/15 & 19 & newer's. So in my case, my 17 was already geared up then I put on bigger OD tires on it which geared it up even more. Vincent & I had a private conversation about gearing and he physically checked his 19 and I checked my 17 as well. With the 26.5 Pitbull's I ended up geared up around 10% VS the factory tires if you included the factory gearing up. So the combination of factory gearing and my bigger tires really made a difference. If I would have realized there was going to be that much difference I would have stayed with 26" tires.
 

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Make up your mind. Is the Weight or the OD?? LOL. I get what you are trying to say though. Most of the weight of a big mud tire is closer to the outer OD of the tire. When I first switched to 26.5 Pitbull's I didn't know if it was the weight or the OD that really killed the performance. Then I squared up the tire's and got back some of the performance. When I squared up the tires I took off like 30 lb of rotating weight. So weight is part of the equation but OD play's a big role as well. Weight rob's HP and OD of the tire changes the gear ratio. The 16-18 are geared up VS 14/15 & 19 & newer's. So in my case, my 17 was already geared up then I put on bigger OD tires on it which geared it up even more. Vincent & I had a private conversation about gearing and he physically checked his 19 and I checked my 17 as well. With the 26.5 Pitbull's I ended up geared up around 10% VS the factory tires if you included the factory gearing up. So the combination of factory gearing and my bigger tires really made a difference. If I would have realized there was going to be that much difference I would have stayed with 26" tires.
I don't need to make up my mind. I know exactly what I'm talking about. It's actually a little bit of both, yes the OD can hurt but it's the unsprung weight of those giant mud tires the majority the mass is at the OD of the tire. So it magnifies the effect. I actually had this all explained to me twice years ago when managing the tire shop. Training seminars from BF Goodrich and from Firestone were both basically the exact same thing talking about extreme mass or rotating mass affecting the performance of an off-road vehicle more than the actual diameter of the tire. And myself I tend to agree with what they say because they put a few more million dollars worth of research into it than I have lol

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Discussion Starter · #186 ·
My issue is ive never ridden a 700 or an XMR (my first choice but all the memes of constantly breaking scares me) and im having buyers remorse already even though all I did was put down a refundable deposit. I know the yami wont have the performance of a v twin. All i can do is watch vids and try to gauge. There is a chance i can do all the clutch stuff and put on 28 Aztex and be perfectly fine with the power launching into holes or rippin down the trails at a nice cruising pace.
The tires you picked out are pretty light so that will help. Still heavier than than the pitbull's I used at 31lb each once squared up but you also have a transmission that is geared down which will help. Even with the 28" tires it's not going to be a pig if you are worried about that. No it's not going to have a V-twin power but you also dont have to be worried about it breaking. Thats the main reason why I have Yamaha's. Reliability is King out in the woods.
 
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My issue is ive never ridden a 700 or an XMR (my first choice but all the memes of constantly breaking scares me) and im having buyers remorse already even though all I did was put down a refundable deposit. I know the yami wont have the performance of a v twin. All i can do is watch vids and try to gauge. There is a chance i can do all the clutch stuff and put on 28 Aztex and be perfectly fine with the power launching into holes or rippin down the trails at a nice cruising pace.
You ll be fine . Machined sheave + a shim , lighter grizzly weights , a stronger spring , and you ll be good to go.

Just use your Low range accordlingly
 

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The tires you picked out are pretty light so that will help. Still heavier than than the pitbull's I used at 31lb each once squared up but you also have a transmission that is geared down which will help. Even with the 28" tires it's not going to be a pig if you are worried about that. No it's not going to have a V-twin power but you also dont have to be worried about it breaking. Thats the main reason why I have Yamaha's. Reliability is King out in the woods.
Also the tire he chose runs about 1/2” smaller than stated in every size

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