CR500 project

carbondaddy · Oct 2, 2012

Picked up a 1990 CR500R which will be the bases of a new Mountain Horse setup. I've sent off the top end for a re-build/porting job, should be 70 to 75 Hp.
Got a pipe, v-force 3 reeds and a few other goodies coming. Those with experience with the big 2 strokes on snow please chime in and give me some pointers.

harrysmith500 · Oct 2, 2012

What oil will you run??

Ausm7499 · Oct 3, 2012

Myself and a buddy both ran CR500's last season and had a blast on them but there were somethings that needed tweaked, changed, and modified.

I would recommend these changes.
-PWK 39.5 Carb
-Delete Airbox and build a snorkel/Pod setup
-Figure out someway to prevent carb icing, we used blankets to cover the cylinder and carb but I am thinking about re-routing a coolant line down that way.
-Vibration at the bars is pretty bad I am going to try putting lead shot and silicone in my bars.
-FMF gnarly

I think that should take care of all the issue that we encountered. The bikes are a blast to ride and that 2stroke power really shines in the light deep powder.

Rush44 · Oct 3, 2012

Someone made a post on here about how to relieve some of the vibration issues on the CR500. If I find it I'll link it.

I'm assuming the KX450 is still in your fleet?

carbondaddy · Oct 3, 2012

Ausm7499 said:
Myself and a buddy both ran CR500's last season and had a blast on them but there were somethings that needed tweaked, changed, and modified.

I would recommend these changes.
-PWK 39.5 Carb
-Delete Airbox and build a snorkel/Pod setup
-Figure out someway to prevent carb icing, we used blankets to cover the cylinder and carb but I am thinking about re-routing a coolant line down that way.
-Vibration at the bars is pretty bad I am going to try putting lead shot and silicone in my bars.
-FMF gnarly

I think that should take care of all the issue that we encountered. The bikes are a blast to ride and that 2stroke power really shines in the light deep powder.

Thanks for your comments. Why the 39.5 PWK instead of the stock 38 PWK, just for more power, or... Did you find carb icing under certain conditions? I was going to try a set of flexx bars and I'm hoping my engine shop can help with the vibs. I have a Knarly pipe and turbine core muffler.

carbondaddy · Oct 3, 2012

Rush44 said:
Someone made a post on here about how to relieve some of the vibration issues on the CR500. If I find it I'll link it.

I'm assuming the KX450 is still in your fleet?

Affirmative on the KX

carbondaddy · Oct 3, 2012

harrysmith500 said:
What oil will you run??

I've been using Motul semi synthetic in all my 2 strokes (bikes and snowmobile) at 40 to 1.

jwilde · Oct 3, 2012

CR 500 bar vibration

I've had a CR 500 of some sort for 20 years, I just picked up a set of Flexx bars, haven't had a chance to try them out yet, may get a chance next week, they're way spendy. I'll post again as soon as I get a chance to try them out. Just ordered a Mtn Horse yesterday for the 500.

Ausm7499 · Oct 4, 2012

carbondaddy said:
Thanks for your comments. Why the 39.5 PWK instead of the stock 38 PWK, just for more power, or... Did you find carb icing under certain conditions? I was going to try a set of flexx bars and I'm hoping my engine shop can help with the vibs. I have a Knarly pipe and turbine core muffler.

The stock carb is a PJ not a PWK, the PWK 39.5 will give you better fuel mileage, and more power. As for carb icing it doesn't matter what carb you have it's going to happen if you don't keep the carb warm enough. I have heard the flexx bars help reduce the vibs but I am not forking out that kind of money until I try some other remedies. If you are looking to upgrade to a 39.5 here is where I got mine http://www.ebay.com/itm/39-5mm-Keih...Parts_Accessories&vxp=mtr&hash=item4d05645b21
he provides all the carbs for service honda and will set you up with the correct jets for your application.

carbondaddy · Nov 11, 2012

Getting close?

steveo10 · Nov 11, 2012

little off topic CD but you still have the rev?

carbondaddy · Nov 11, 2012

Rush44 · Nov 12, 2012

One of the cleanest looking CR500's I've seen. Great bike man... I hope it's a ripper for you.

4Z · Nov 12, 2012

Nice!

An easy mod for a few more ponies is the head mod Fastrax does. I went with the compression release option as well. They gave it a modern squish a raised the comp to my spec.

Jon Mutiger · Nov 12, 2012

Your gonna need more fuel than you can imagine. I rode Alvin's CR500 with a 2moto and it ripped. Starting it wasnt the best but it rode awesome. It used over twice as much fuel as my kx450f did. You will need probably a total of 40litres for a good pow day.

diamonddave · Nov 12, 2012

Oh man...I don't need to see my favorite bike ever built being turned into a snowbike, I just don't have the $$$$ to do mine.

The stock jetting from Honda isn't even near being close. I know after rejetting my 2001 (on the dirt) my fuel economy went way up. This is with the stock carb though. I would burn just a tad less than my buddies with their fart sounding 4 strokes. Of course dirt and snow are way different.

The one thing I'm curious about is a rekulse clutch on a 500 in the snow. anybody use one or have the ambition to use one?

Lynn, the compression release you had Curt add.....does that allow for engine start (kick) without having to have kick starter at the very, very top of the throw? I've got mine figured out how to start on first kick each time and 2 times when cold but finding TDC with the starter can be time consuming sometimes.

Just curious, Anybody make an e-start kit for the 500?

M5- · Nov 12, 2012

So whats a guy do for lights, heaters etc on one of these bikes. I see Baja Designs offers a 180 watt external stator just not sure how that would all go together .

M5

Ausm7499 · Nov 12, 2012

I have found the fuel consumption between a comparable displaced four stroke to be nearly identical with the mh setups

4Z · Nov 12, 2012

diamonddave said:
The one thing I'm curious about is a rekulse clutch on a 500 in the snow. anybody use one or have the ambition to use one?

Lynn, the compression release you had Curt add.....does that allow for engine start (kick) without having to have kick starter at the very, very top of the throw?

I tuned my Rekluse in so that the bike would not stall. Slip was minimal and you could still actuate clutch as normal while riding Ended up with over twice the TC balls they recommended. Worth every penny.

The comp release made it easier to kick over, more like a 250.

carbondaddy · Nov 12, 2012

The motor has been bored out to a 520, it has a fairly extensive porting job and the squish band has been changed but the compression remains similar to stock with the exception of the decompression grooves removed. It has an FMF pipe, V-force reeds and I'm waiting for the 39.5 carb to arrive. It should be good for about 75 HP. As for fuel consumption, I've read that a properly jetted 2 T isn't much worse than a 4 T. This bike has the long track and is about 20 lbs. lighter and will have 20 more HP than my KX 450, so it should be more efficient through the snow. Time will tell. No hand warmers, but I have a set of gauntlets and a battery powered LED setup. I will probably end up with a Rekluse, as with my KX 450, But will try without it for now.

CR500 project

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