Cr 500 af

[Deaf Bob]

Looks good.. Wish I had the balance to handle a bike like that!
Get where you are coming from about a fresh set of eyes...

[SuperBuickGuy]

Loud, vibrates, stinky... in short, perfect. Ride Honda got it running (weak spark) and gave it the required off-road inspection (we don't inspect cars for roadworthiness, but we inspect dirt bikes - go figure). Once I get a good chance of riding it, I'll post a picture of the day.... oh wait, I've looked into the future and found a picture of the day.

[mike343sharpstick]

It's impossible to break all those bones at once one a dirt bike, even a CR500. It would take two or three outings.

[SuperBuickGuy]

It's impossible to break all those bones at once one a dirt bike, even a CR500. It would take two or three outings.

Good to know, but knowing me - I'd find a way (my middle name is "I've never seen that before")

the bike currently

[SuperBuickGuy]

completing the record.... little stuff
the boot on the spark plug was a temp, so I borrowed another boot, split it so that it'd go over the plug connector and screwed it together

and remove the zip ties and weld a petcock valve holder in a new location


and protect the radiators


forgot one thing - I need to weld a stanchion to hold the expansion chamber in place.... but not yet, it seems to be leaking so I might have to get a replacement (really ugly welds on the current one - suspect rust)

the motorcycle shop complained an exhaust leak... think I found it

actually, the bolt to the seat frame came loose - since the muffler is bolted to the seat frame... the pipe came out

and the a#1 best way to make me smile and recommend your service is to put a filter on, and not tell me or charge me for it .... that will pay them off handsomely... promise

[SuperBuickGuy]

it has now been ridden.... just one word

awesome!!!!!!! gol-dang this thing is quick, from off idle to redline, it will run away from you if you let it.... in short, PERFECT

*since I've not been terribly clear lately, let me just say
*I love it!

so I found out what was done to it.

reeds and cage (boyenson)
ported
larger piston (+10)
clutch work
FMF pipe and exhaust
pwk 38 carb

this thing is a beast - I'm so going to hurt myself on it

which, after the google search, is what the guy did to his on the video that leads in this build.... yep, stock is just too reliable. I'll tell you what, you have to kick it like you mean it, otherwise it'll just toss you off.

[Beagle]

I'd go ahead and order a spare kick starter gear and wear MX boots. The worst part about kicking like you mean it is when the the gear lets go and you find the foot peg with your shin... which is why I don't ride my CR250 any more.

I'm too lazy to look, does it have a power valve exhaust or is it just normal old light switch big bore pull then insanity on the pipe?

[mike343sharpstick]

That's great! I still think it amazing that an old CR500 lump fits so well in a new frame.
I hope to be riding this weekend too

[SuperBuickGuy]

I wear shoes with a stiff arch support, and those work great for kicking - but MX boots are on my wish list

no power valve exhaust

[SuperBuickGuy]

Time to start getting this dialed in.....
a PJ 38


if you look closely, the top left reeds are hanging open (and now we know why it's hard starting)


and an inside picture.... I'm going to get a new bucket of carb cleaner tomorrow, remove the plastics and give it a dunk because it refuses to idle and doesn't have a crisp off-idle

[SuperBuickGuy]

if anyone needs pictures of a PJ Keihin 38 mm carb... here they are (I mostly did this to keep track of what it looks like together)







from left to right rubber washer, brass washer, spring


back together awaiting the rebuild kit.

[mike343sharpstick]

finally I can talk about a carb I know how to tune!
Sorry If I go over junk you already know.

Hard starting will have to do with your idle mixture screw, #14 on attached exploded view. Screw it in all the way, and back it out 2.5 turns and adjust from there. Screwing it in restricts air (richer) and out is leaner.

Off-idle is tuned with the low speed jet, #17 on the exploded view.
This is often over looked, but very important. When I switch from summer to winter tuning I change both the low-speed and main jets. Main Jet ONLY tunes WOT.

[SuperBuickGuy]

finally I can talk about a carb I know how to tune!
Sorry If I go over junk you already know.

Hard starting will have to do with your idle mixture screw, #14 on attached exploded view. Screw it in all the way, and back it out 2.5 turns and adjust from there. Screwing it in restricts air (richer) and out is leaner.

Off-idle is tuned with the low speed jet, #17 on the exploded view.
This is often over looked, but very important. When I switch from summer to winter tuning I change both the low-speed and main jets. Main Jet ONLY tunes WOT.

I'm waiting for new gaskets, but once I get them; I'll use this information - thanks a lot!

There was crud in the carb when I dunked it; so I suspect that it was set up correctly, just dirty.... of course, I had to remove the idle screw to properly clean....

[SuperBuickGuy]

well, I got the parts yesterday, but life kept me from doing the work...
New reeds/cage


some modification is required



installed after a bitter battle with float levels


and bike is done (okay, I have one aluminum bit to weld on; but that's coming later)

[SuperBuickGuy]

it runs, it flies.... I still have to get the float level right. I've never met a more persnickety carb (about the float level, and that includes the quadrapuke). Right now, at idle it rattles fuel out of the overflow. once you get moving, not so much. I also need to check for a head gasket leak - I'm not sure, but I think I've got one (not a big deal since I didn't change the head gasket or flatten the head when I welded on it - meaning, kind of expected)

I checked the head/cylinder temps with a heat gun after riding it a bit, 110-160 depending on location.... but I'm still thinking it might have a head gasket issue.