The Polaris 500 HO Engine sits at a pretty extreme angle on the Sportsman Quad. On the odyssey, the extreme angle would run into the seat more than likely.
Because I'm planning to retro-fit one of my fl350's I was wondering if making a custom carb mount would affect anything related to Engine performance.

The picture below shows where the carb would sit if the custom mount was between the Carb and the Engine.
Would the Engine function normally if I fabricate a mount like this?

Would it effect the oiling if you change the position of the Engine? I don't know but its something to consider.

As I understand it, it's a dry sump Engine. Does that make a difference?

I honestly have no clue. Havn't read much of anything on 4 strokes. Would hate to give you bad info. I'm sure someone with more knowledge will pop in.

There was guy that used that Engine in a ody for his wife a few years ago on MBN.

He tilted it upright and said it ticked but still ran it anyway.

The pics are gone now,it was like 08 or 09.

He cut a wedge out of the origial intake boot and glued it back together.At the time he put 30 hours on it with no problems.

Its only like 30-35 hp you know.

I would look into the oiling system before wasting any time on it.

Dry sump or not I think its all about where the oil pickup is located that matters.

I would not run the Engine without a oil pressure gauge if your going to change the angle just to be safe even if its only a temporary gauge.

How many RPM will this Engine turn ?

30hp? That's not a lot. They're Like 28 stock? Not to be negative but if you have a stock Engine not sure it's be worth the effort. May I ask why your considering the swap? Missing the stock Engine?

Are you suggesting the HP is too low for the Odyssey 350? Was this guy of the opinion it was underpowered with this Engine?
And yeah...I need a manual or more info before I move forward.


I'm not quite certain.....I read 7000 rpm somewhere but don't quote me on that. I realllly need a manual or more info for this Engine. It's a 2004...hardly used and I picked it of for 400 bucks.
It's in great shape...but I'm kinda wondering how it would run the Ody.

Yes and no. I have most of the stock Engine.....but I really wanted to get away from the 2 stroke and move into a 4 stroke.

You can mod the stock Engine and make quite a bit more power than you can with that 4 stroke Engine. If you were to rebuild the stock Engine without major mods it should be very reliable and cheap to rebuild when it needs it. I do believe my Engine was on the original bore when I bought my odyssey and it still ran. I'm not crapping on your idea. A more modern Engine would be nice for parts availability. Just make sure to do your homework on all the issues that could come up like your doing. Would suck to go through all that work and find out the engines ticking or wearing excessively. Would defeat the purpose. Least I'd be bummed if my Engine was ticking. Means something isn't being lubricated. Will certainly be a future problem.

Fatcat, by no means do I take your comments as anything negative. In fact I appreciate them more than you know. That goes for all who read this. By all means speak your minds, I will be the first to tell you I am brand new to all of this and have little experience dealing with HP, what works what doesn't, what type of 4 stroke Engine would make the Ody run like the stock 350 ect ect.

Having said that this post has shed some light on a few things I didn't really think through well enough. For example one reason I chose this Engine was because it was 400 bucks and they normally sell for 600 and above ( I like re-selling for profit) and also because I read in forums that this Engine was a pretty straight forward retro-fit.

I figured I would buy the Engine, and either chose or not chose to use it afterwards...since passing it up at the price I got it for would have played in my head for weeks to come.
But now after reading some of your posts....I'm seriously wondering if this is the right Engine for what I'm trying to achieve.

Originally, I thought the 35HP would be enough due the the torque the Engine provided, but its sounding more and more like the Ody won't behave the same as with the 350 2 stroke Engine.

Trust me, I am all ears on this, so please don't feel like I take it personally....you guys provide great information and I always welcome a chance to educate myself further. :)

I'm not very real world experienced myself. I'm just a dork who likes to read and I like this stuff. Depends on what your goals are. Do you want reliable or tons of power on tap. Not sure if torque makes a huge difference. That's the beauty of the cvt. I scratch my head when I see people switching over to an Engine with a manual clutch. With the cvt you can adjust the clutch to go where the power is. 4 stoke bottom end won't make a big difference really in my opinion. If your clutch is set up well it won't engage until the 2 strokes making good torque. Or you can have your cake and eat it to. Rotax it. I've strongly considered that option but my end goal is to have this the girlfriends machine and pretty sure it would scare her. It might already. Besides that it seems like the perfect option to me. I don't have crap for fab skills really. I'd buy the bolt in Engine mount, pipe, etc. from Farr Offroad and find a dirt cheap sled to do the swap with. Double or even triple the horsepower with bone stock reliability. Sleds run 5000+ miles without being rebuilt. Bolt in to. Would have to figure out a fuel tank, radiator and mounts, and intake(air cleaner). It's all been done before. Just tweak it to perfection or your taste instead of starting from scratch. What I did on my odyssey is read around in here and found all the mods I liked and seemed to be proven well and did some touches to my taste. I guess I'm a user. Lol. Used other people's bad experiences( a hmmm $$$) to figure out what I wanted to avoid. Got to be people out there willing to try other options though to. Somebody had every one of these ideas I like so much and were the first to do it. Always up for that but its lots to think about.

Lol! Nothing wrong with reading other people's trials and tribulations. ;)

There is a post where a guy shows a pic of the 500 HO in the ody and he swears by it.....BUT...he never responded to Hosers question and I've mailed him 2x's to see if I could get some info.

I have lots of fabricating experience, but little Engine knowledge for the do's and don't's. I can work on them tune them up and all of that....
Now as to what I want out of this Engine, or rather what I expected...well, I'd say the same performance as the 350 2 stroke but in a 4 stroke flavor.
However....100 HP vs 35 HP is seriously making me wonder.

OK Athis, since you are ready and willing to listen to other peoples opinions and keep an open mind, (good for you), I have a friend of mine that has a Polaris Sportsman 500HO quad. My mildy modified Ody will smoke his 500 effortlessly. Top speed of the Polaris 500HO is around 53MPH maxed out.

Now the Polaris Sportsman I believe is around 100 pounds heavier at around 695 pounds.

I have no clue as to the gear ratio of the Polaris and this might be the factor as why it is so much slower.

Just my 2 cents worth.....

Rand

This is my buddies son's buggy. It has a 2000 Sportsman 500 Engine in it. Scrambler 3:1 FNR box, 3:1 chain reduction, 25" tall tire.




Great running little Engine. For the most part, for the trail riding that we do, it works good. But he has to push it pretty hard to keep-up. It will turn 7000rpm, but it is not making any power up there. It pulls good at 5500-6000. Might do 50mph on a hard flat run but takes a while to get there. If speed and power is the goal... maybe not the best choice.

Depending on the type of riding you do, I'd be concerned that the extra reduction of the Oddy gearbox is going to keep this Engine above optimum rpm. Your clutching is going to need some good overdrive to keep some load on the Engine.

As far as the carb mount, it'll work.
As far as the oiling, I too think you have a problem standing it up that far. The oil pump pick-up can't be above the bottom of the crank. The crank can't be splashing the oil around.

You need to match the RPM if you want the same top speed without a gearing change.

A 4 stroke Engine only makes a POWER STROKE every other rotation of the crank shaft a 2 stroke Engine makes a POWER STROKE every rotation of the crank shaft

A 2 stroke turning 7000 RPM is making two times as many power strokes as a 4 stroke Engine is at 7000 RPM

2 stroke 7000 RPM = 7000 power strokes
4 stroke 7000 RPM = 3500 power strokes

I'm all eyes in this case :P haha. But seriously great points! I'm just trail riding...no racing or anything like that. Having said that, I do enjoy and still want the power to spin the rear wheels and get the back end to drift. Top end doesn't concern me honestly..I can't imagine rolling in an Ody at 53 mph.


Ok...excellent info and thank you for the video! But help me out a little...."Scrambler 3:1 FNR box, 3:1 chain reduction" <---- you mean it is not using the Ody stock Tranny?


I suppose describing my "ideal" driving style may help. Like I mentioned to Radman, I'm just trail riding...no racing or anything like that. Having said that, I do enjoy and still want the power to spin the rear wheels and get the Ody to break the back end and drift. I would like a good response to throttling in the 20-40 mph range. Top end doesn't concern me as much honestly....I can't imagine rolling in an Ody at 53 mph.


Agreed...I'm going to look at this seriously before I decide anything.


Hoser, how do you think it would affect the range of riding I describe to DaveM?

Give it a try see what you think for average trail riding I think you will be happy best way would be to take your Odyssey on a ride trip with a GPS then look at the log when you get home see what your top speed was and what your average speed was.

This isn't an Odyssey, it's a homebuilt machine. It has a Polaris Scrambler 400 trans to get the CVT and FNR, which is 3:1 reduction. Then chain drive to the back axle, which is another ~3:1 reduction. This and tire size gives you final drive ratio's.

(This pic was before the Sportsman500 install)


The FL350 box is about 10% more reduction than this set-up, (with an equivalent size tire). Couple that with an Engine that is maybe 2000rpm shy of the stock 350 and you can see that you'll be down on top end, and need to do some clutch test and tune to find the 500's sweetspot. If your Engine is running above it's powerband all the time it will feel lazy and slow. Your not utilizing the power well. If your short on gear ratio the Engine will be screaming at cruising speed . In order to keep the 500 in it's optimum say 5000-6500 range you are going to have to either give up a bunch of top end and risk high rpm cruising, or increase the amount of overdrive in the CVT.

I am the one that has the Odyssey with the scrambler 500 in it. This is the 4th or 5th season with it in the Odyssey and not one problem. The tick was in the Engine before I took it out of the scrambler and and has not gotten any worse. It has at least 800 miles on it since the convertion.

I tried cutting the intake in in half and flipping 180 degrees. That got it to line up but it keep cracking. I end up get the intake off of a Polaris Predator 500, that intake goes straight out and works perfectly. I also used the cooling fan off of a Predator for the radiator. I used the stock polaris clutch and the stock honda driven with no changes and it seems has been working great. The clutch could used to be dialed in a little bit, but it has good low end and I have gps top speed of 55 mph.

Hit me up if you have an question.

Hey Oddybuggy, good to see you. I tried to find your old pics but they're gone now.

There you go Athis, about as much info as your going to get.

Man, I gotta tell you guys I love these forums! After reading your last post I have a good mental picture ( the videos reallly helped!) on what it might be like having this Engine in the Ody.
It's still a lot of unknowns....with the worst case scenario being a slow and sluggish response buggy. That's not something I want to accomplish given the amount of work plus the cost of purchasing the rest of the Engine parts that will complete it.

I'm really surprised given the amount of folks modifying these little guys that there isn't "Thee" 4 stroke Engine out there for retrofitting. I mean, the 2 strokes are just as close to my heart as any one else's.....hard to beat the HP and response of a 2 stroke. But considering the costs of repairing the stock 350, it boggles me how there's not a 4 stroke of choice which mimics the characteristics of the 350 with a more reliable/inexpensive Engine to repair.

I have homework cut out for me now......I need to make a big decision on whether or not I should jump into modding the Ody with this type of Engine because eventually I was planning on making the same mods on the other 2.

Indeed Bull.....and extremely appreciated! :D

I apologize Oddy, I ran out of time to post before heading home. Thank you for the information! Do you have video of it running? I would love to see pictures and could give you my e-mail if you like.

Well there ya go. Real world experience trumps theory. Surprised to get 55mph. Oddybuggy, what size tire are you running? It would be interesting to figure out your CVT ratio with the Polaris primary.
And pics would be good just to see others handywork.