Redbull500's Gen. 2 Cr500 with 86 engine

Redbull500 · Post by **Redbull500** » April 5th, 2013, 9:48 am

hey guys so this is a video of the bike being started up today, what do you guys think? sea level or dam close to it, 39,5mm keihin airstriker, 50 pilot, air screw 1 1/3 out, dgn needle 4th clip down, slide #7, 180 main, last summer the bike was going into lean surges when on the pilot...

temperature is 2`Celsius so 35` farenheit

87+ crank, 1 overbore, bottom end completely redone last fall, needs new top end, new v force 3 reeds and reed spacer, full pro circuit pipe, new air boots, carb is 1 year old, jets are new and I cleaned the whole carb out before I started it up, carb was drained empty for last few months of winter storage

https://www.youtube.com/watch?v=ghw-2PD5nkM

thanks for any help/advice guys

fmikhele · Post by **fmikhele** » April 5th, 2013, 12:06 pm

Sounds dumb, but is the slide bottoming out in the carb i.e when you crank the throttle and left off quick do you hear the slide bottom out in the carb? Possibly check how your throttle cable is routed. Check where the carb cable goes into your throttle and the cable into your carb. Sometimes its the simple things...

hoofarted · Post by **hoofarted** » April 5th, 2013, 1:07 pm

fmikhele wrote:Sounds dumb, but is the slide bottoming out in the carb i.e when you crank the throttle and left off quick do you hear the slide bottom out in the carb? Possibly check how your throttle cable is routed. Check where the carb cable goes into your throttle and the cable into your carb. Sometimes its the simple things...

^^ that too. I thought it sounded like an air leak.

josh · Post by **josh** » April 5th, 2013, 1:50 pm

i am at 4300ft, and i run an pwk air striker: 50 slow 160 main #5 slide dgn clip second from top, 32:1. i have gone from pig rich, fouled plug on the main and getting closer. my slow jet is still too rich,

assuming all the moving parts are working properly, i think your slide is too lean, go to a #6.

Base line for Service Honda CR500AF with 38 and 39 PWK. These were obtained from AJ himself.
Main - 175
Pilot - 55
Needle - 1368N 3rd clip position
Slide - 6.0
AS - 1.5 turns

http://www.bannedcr500riders.com/board/ ... .php?t=203

http://cr500riders.com/cgi/yabb/YaBB.pl?num=1173903663

Redbull500 · Post by **Redbull500** » April 5th, 2013, 3:23 pm

so to answer those questions, good idea fmikhele but the slide does bottom out properly, and its a new cable and slides really smooth, here ill post the video of when I first got it

Redbull500 · Post by **Redbull500** » April 5th, 2013, 3:43 pm

here it is

http://www.youtube.com/watch?v=e1hecrww ... e=youtu.be

so thats how it ran before and when the motor first went into the aluminum frame, except less smoke, the old pipes were clogged full

fmikhele · Post by **fmikhele** » April 5th, 2013, 4:06 pm

I'm assuming you've had the common sense to try adjusting the idle correct? Does the idle adjustment have any effect at all?
In your first video (the engine in the AF) Sounds like it was idling fine and then your either gave it some throttle or turned the choke off (hard to tell from the video) A little more description of what it is doing would be helpful

i.e idles fine with choke but revs like crazy without choke, or little blip of the throttle and the revs take off etc

Redbull500 · Post by **Redbull500** » April 5th, 2013, 5:11 pm

Ya the idle adjustment i put almost completely out, in the video I didn't touch anything that was the bike doing the changes on it own, I started it again and playing with the choke has little to no effect, basically I turn on the bike and the engine takes off out of control, plug is black so is the piston and everything looks nice and lubed

fmikhele · Post by **fmikhele** » April 5th, 2013, 5:20 pm

believe one of two things is happening. (1) The throttle cable is pitched somewhere and your slide is not bottoming out. I would first try loosening all the bolts holding the tank in place but leave the fuel line connected, and ease the tank up a bit and play with the throttle cable slack a little and try start the bike a few times. The cable likes to pinch its way between the tank and frame which I have had cause a high idle in the past. (2) something is drawing air between the carb and the cylinder. Could be a cracked intake boot or a bad reed cage gasket like hoofarted was getting at...

Redbull500 · Post by **Redbull500** » April 5th, 2013, 5:27 pm

Ya I thought it could be leaking air from the intake as well so I took it all apart, the boot is brand new, i took out the reed spacer, put new gaskets and re-torqued it all good but it still just runs away. Ill try the cable stuff again tomorrow morning and see what happens, why would the engine start running away if the cable was tight tho, would it not just give more throttle?

fmikhele · Post by **fmikhele** » April 5th, 2013, 5:51 pm

The cable sheathing (tube) is essentially a rubber coated spring under tension it stretch's but the cable does not so the "slack" is reduced.. See the figure sorry I'm exhausted so its rough

No tension --> slack = total length - spring length (no elongation)
Pinched cable i.e "tension" --> slack = total length - spring length (elongated)

THROTTLE by fmikhele, on Flickr

Redbull500 · Post by **Redbull500** » April 5th, 2013, 6:02 pm

Haha no worries, so if I understand this properly if its under tension it takes away the slack and doesnt let the slide close fully, slide open more= more throttle? I just dont understand how that would make the engine run away

fmikhele · Post by **fmikhele** » April 6th, 2013, 7:57 am

Any luck?

Redbull500 · Post by **Redbull500** » April 6th, 2013, 8:06 am

ill be starting it up in about one hour with a response, too early yet and I live in a tight packed townhouse sub division, my buddy told me to unhook the throttle cable from the carb to isolate that variable

Redbull500 · Post by **Redbull500** » April 6th, 2013, 8:56 am

so we have a winner with the throttle cable as an issue, trying to reroute it properly as we speak but you nailed it fmikhele, started right up and iddled niecely with throttle cable disconected

Redbull500 · Post by **Redbull500** » April 6th, 2013, 9:52 am

found another big issue, my 39.5mm keihin pwk was brand new when placed on the af500, the plastic idle screw had not been touched by me till near the end of last summer when I was working on the iddle (it came almost fully out so wasnt holding the slide open enough), decided to clean the carb thoroughly before reassembling and found that by tightening the idle screw it had pushed bits of what appears to be some sort of lock tight into the carburator slide area

I took out the screw and it was covered almost the full length in the stuff, (perhaps comes like that to keep air tight??) slide and carb were not damaged thankfully, something to look for tho

fmikhele · Post by **fmikhele** » April 6th, 2013, 2:41 pm

glad to help

hoofarted · Post by **hoofarted** » April 8th, 2013, 7:05 am

Glad you got it sorted. Sometimes its the simplest things that drive you nucking futs!

Redbull500 · Post by **Redbull500** » April 8th, 2013, 7:15 am

Ya I was beggining to worry, sub frame is going out to my buddies shop today to get the back tabs rewelded for the gen3 fenders

Redbull500 · Post by **Redbull500** » April 8th, 2013, 4:26 pm

top end came off today

Redbull500 · Post by **Redbull500** » April 8th, 2013, 4:38 pm

the wiseco anchor

fmikhele · Post by **fmikhele** » April 8th, 2013, 4:43 pm

Your head is a little scary looking

When was the last time the bottom end was serviced? Might want to dig deeper then just a top end! No lube holes on the forged piston Bob will be on your ass about that... Is the exhaust bridge relieved?

Redbull500 · Post by **Redbull500** » April 8th, 2013, 5:01 pm

Ya

lol previous owner obviously messed up... bottom end was all redone in the fall all new seals and bearings, the top end wasnt done because all I was doing was fitment of the electronics/body and testing the pilot circuit. I wanted to do my research over the winter and make a decision on the route I wanted to go with that top end, I had a retired honda mechanic do it all for me and he said I could do the tinkering over the winter like that but come spring finish the rebuild up top (I hadnt seen any of the top end till now) its pretty scary

Redbull500 · Post by **Redbull500** » April 9th, 2013, 7:10 am

I think the exhaust bridge was relieved on the previous bore but then just honed out and slapped together this time

jr475 · Post by **jr475** » April 9th, 2013, 12:13 pm

You a hockey player of are you getting ready to put a redneck body lift in?

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Redbull500's Gen. 2 Cr500 with 86 engine