CR500 Budget build and all things Cr500

[Uncle si]

I have an idea of the running hot! Head gasket possible or a tiny crack or mark on the head gasket surface. I had a similar problem on a 2 stroke I had!

I have a million dollar question!!!!!!
How do these 500's (which I love) run against the big bore 4 strokes like the husaburg 570 or ktm 525? Especially in the mountains! Honest answers please! I want to get started on my own project ASAP! Just not sure what way to go yet!

Regarding running hot - I think that for many of us, the conditions and our speed simply don't put enough air through the radiators to cool a big motor that is working hard.

Sure you can have other issues, but look at how different an environment these bike live in compared to their intended use. I don't see a lot of trials riders on KX500s, reving the piss out of the motors and only putting air through the radiators at an avarage of 10MPH.

On the two strokes, I agree with the other posters. One thing you give up is the smoooooooth powerband. 500s require more attention to engine speed.

 

[summitboy]

Only one speed. Tapped !

 

[Patches88]

Water pump cover inspection

Huh, way leaner that what I was running. 175, 55 & DGH #4. Anyone had experience with fat jetting causing excessive coolant temps?

Sure sucks there's no snow around here to go test any changes out!

Definitely looks like you should take your water pump cover off and see how much corrosion is in there. Corrosion is especially known prevalent with the pre 89 engines. Check the impeller of course and see if you can get an upgraded one. If you have corrosion then better check the rads for plugging too. Likely sulphate reducing bacteria living in the water while the bike sits for months unused turning naturally occurring fresh water Sulphates into Hydrogen Sulphide which is corrosive and the bacteria poop is Black Iron Sulphide. Some low PH acid may clean up rads if they are plugged, HYDROGEN PEROXIDE 3%—Antiseptic, Anti-bacterial is an alternative to chlorine bleach.
If there is corrosion get out the grinder and clean it up. Then fill in the holes with JB weld and let it dry. Then clean up the JB weld with a nice dremel buffer to make it smooth. The new impeller will move more fluid too.
Good luck!

 

[kell8071]

Yeah, I checked that and everything looked good. Rads are aftermarket fluidynes and looked fine as well. It did have radiator guards that I have since removed but with the lack of snow have not been able to test.

Definitely looks like you should take your water pump cover off and see how much corrosion is in there. Corrosion is especially known prevalent with the pre 89 engines. Check the impeller of course and see if you can get an upgraded one. If you have corrosion then better check the rads for plugging too. Likely sulphate reducing bacteria living in the water while the bike sits for months unused turning naturally occurring fresh water Sulphates into Hydrogen Sulphide which is corrosive and the bacteria poop is Black Iron Sulphide. Some low PH acid may clean up rads if they are plugged, HYDROGEN PEROXIDE 3%—Antiseptic, Anti-bacterial is an alternative to chlorine bleach.
If there is corrosion get out the grinder and clean it up. Then fill in the holes with JB weld and let it dry. Then clean up the JB weld with a nice dremel buffer to make it smooth. The new impeller will move more fluid too.
Good luck!

 

[Patches88]

Rad Fluid

Yeah, I checked that and everything looked good. Rads are aftermarket fluidynes and looked fine as well. It did have radiator guards that I have since removed but with the lack of snow have not been able to test.

Good. What fluid is running through those rads?

 

[M5-]

I had an issue with my bike heating up and pushing coolant out past the rad cap so I rigged up a coolant recovery bottle and switched from a 1.1 to a 1.6 bar rad cap. Problem solved. Rad caps are available up to 1.8 bars for the Cr500. Just something else you could check.

M5

 

[SEOINAGE]

Pretty interesting build. Isn't the track the most expensive part? Or is there some way around the 6k tag I am seeing on their site?

I have a 2010 yz450f I ride in the dirt, and then a few other machines. I have an 88 cr500 I had originally planned on converting to an aluminum frame, It has a little motor work done on it back in the day, quite powerful, but needs some serious work, so it has been sitting.

I figured if I used it as my sled bike, I could save a lot of money as opposed to trying to squeeze the power out of my 450 with a turbo etc, like you mentioned. Yet have a lot more power than a stock 450. Middle ground with much less cost.

I would basically have to do something very similar to what you have done with the fork upgrade, and with the track it is basically ready to go in the suspension department.

I had looked at some used tracks, and saw a radix for 1k, which could be an ultra budget way of getting in, but wouldn't quite satisfy. The bike itself still needs work, and not sure if I would prefer that or using my 450. I haven't taken the water impeller apart yet to see if it is rotted out, but I'm worried it has been a bit jerry rigged by the previous owner.

I just broke my hand last week riding, so now I am keyboard bound, and curious about getting into this sport, now that I see how far things have come. I'll have more questions about your build later I'm sure. If I buy my wife a new couch I might have some freedom to add to my toys.

 

[M5-]

I personally wouldn't waste my money on a Radix or 2Moto, there's a reason its only a $1000 bucks. There are starting to be some really good deals on used Timbersleds and there will be better deals in the near future. You should go ahead and buy the new couch because after you get into this sport get addicted and spend a bunch of money you will need somewhere to sleep so a nice new couch sounds pretty good.


M5

 

[SEOINAGE]

Haha great idea hadn't quite thought of that. Ill try to ease into it so it doesn't seem like I disappeared. But I can already picture how that will turn out.
I'll start looking at used timbersleds for sure, how well do they hold up with time and use?

 

[kell8071]

Good. What fluid is running through those rads?

Just some cheap ethylene glycol currently, I will likely swap to engine ice if I can't fix it with other updates.

I did review my setup and realized I had my coolant temp gauge routed before the thermostat on the RH side. The left hand side had a ball valve since I had expected to have problems getting up to temp! I pulled the ball valve and moved the temp gauge to the LH side in the hopes that the readings were artificially high due to too much restriction from the T-stat.

Unfortunately with this winter I may be waiting to see if this helps for a long time...

 

[jethro450]

Hey M5 where did you get your fittings for your carb heater? And hose too I guess, I'm gonna maybe try to get this thing together and try some spring rides on it before the snow melts too fast (which it is right now at a very fast rate).

 

[M5-]

All the brass fittings came from the local auto parts place, I had the shut off valves kicking around but there is a nice valve from Doo you can get that works well. I buy the silicone hose locally at an industrial supplier called Greenline, they are hose and fitting specialists, they sell the brass fittings as well.

M5

 

[jethro450]

10-4. I'll see what I can find locally. I want to support thermo-bob but $125 for some hose, clamps, and whatnot seems a little pricey. I do want to get a thermostat from him.

 

[wwillf01]

Hey M5 where did you get your fittings for your carb heater? And hose too I guess, I'm gonna maybe try to get this thing together and try some spring rides on it before the snow melts too fast (which it is right now at a very fast rate).

I can tell you this I would go without the stat....I will have one shortly for sale.. I have both Avid and Ktm Just put a switch in to turn on the carb heater as needed...

 

[TheStrayCat]

M5 or Summit Boy, do you guys have any videos of the 500's riding? climbing?

 

[M5-]

M5 or Summit Boy, do you guys have any videos of the 500's riding? climbing?

Unfortunately, no on the video, I haven't shot any video period this year, I've been kind of lazy.

M5

 

[portgrinder]

one thing we noticed on my kx5 is that power drops off quickly as coolant temp goes up. i would imagine its the same for a CR. theres likely better cooling around the ex side of the cylinder than the kawi, but the iron vs nicasil sleeve probably makes that even.

 

[jethro450]

Ran into a small snag.

The chain is way too tight with a 13t sprocket. I think the kit is stock with a 16T jackshaft sprocket (will check later). So tight I don't know if I'd dare run it. I added a link and put a 14t sprocket on but it's so loose it won't work, still rubbing the track with another 1" or more of slack to go.

So I have two, maybe 3 options; want your thoughts.

First of all, the chain is probably already 50% stretched/worn which leads me to thought
#1 - I could run it with the 13t super tight and hope it stretches soon so as to not damage bearings. See above though, I'm sure it's already stretched at least 50% and purposely stretching it more will eventually lead to prematurely worn sprockets on my kit. Don't care about worn sprockets on the bike but I do care about TS sprockets. Also, running it super tight could damage bearings on the kit and motor... But who knows, it's a 500, maybe it'll stretch that chain in 5 minutes and everything will be fine.

#2 - Potentially try one of these half-link things and see if that'll put the chain in the right adjustment zone using a 14t. But I've never used one before and honestly, I don't know if I trust them. Not sure how strong they are.

#3 - Go buy a 15t sprocket and see what it does to the slack on my extended chain.

What do you guys think?

PS - only thing I needed to make the kit fit for the 500 motor was some spacers. I was all happy until I went to install the chain...

PPS - Not sure why pics are upside down.

 

[summitboy]

Why not run a 14 ? I run 14/16/17/20. No link. New and stretched chain.

 

[jethro450]

See #2 above. It doesn't fit like it does on your bike.