'05 Gen 4 / '88 500 Conversion
Posted: July 22nd, 2013, 6:01 pm
Hey folks,
Did my 1st AFC thanks mostly to you guys here that have or are currently doing the same. After poking around here for a few yrs I finally figured there is enough info & hardware out there to help me do the swap pretty quickly (by that I mean little to no trial & error set backs). The info here is really very valuable & I commend all of you for sharing. I hope to do the same.
I'm from NH & mostly ride the power lines around New England. I have an automotive mechanical & machining back round & a fairly well equipped garage / small machine shop but it's not my source of income....hobbies only (man cave). I can machine my own parts when there are no other options which makes things much easier.
I started with an '05 CRF250 & adapted my beloved '88 CR500 (that I've owned for 20+ yrs) engine into it. After reading a lot of your threads, it became apparent that the Gen 4 is one of the more involved conversion approaches & adding to that an older 500 engine made it bit more challenging. Although not as common, there is still info on my combination here on what I'd run into with the older engine.
I have PNs & sources for everything I bought so please just ask if you wanna know.
I bought the kit from CP500 & his parts AND support are high quality. I'm equipped fairly well to do all the fab work but had to find a good welder to make my alterations permanent. I started this on 4th of July weekend & just fired it up for the 1st time yesterday. All seems ok & will take it for a real ride this weekend.
I used a combination of many of your all's ideas & the build went fairly smooth. Some of the issues I ran into weren't really talked about that much here so I had to just do What I thought was best. (Yeah, I should've created my account & asked a few questions earlier, but I figured by the time I got a response, I'd already be past the issue).
I decided to make my own rear engine mount collars rather than boring out the case & went with everyone's suggestions for the spacers. they work perfect.
I elected to go with left & right radiator inlets as opposed to a single outlet mod at the head. I got the hoses from Australia as recommended in one of the threads here. For me, it's a much cleaner approach & the hoses can be cut to fit perfectly.
I used a couple of Ebay/China extra capacity radiators & although they seem like they'll keep the 500 cool, and they seem much more rugged than the Honda rads, I had massive interference with the new FMF Gnarly pipe on the right side. I had to carve a pretty good chunk out of the bottom corner to make it fit.
I elected to use a rear pipe mount as opposed to some saying it's not needed. I also had to cut & reshape the pipe into my silencer a bit to make it fit with the original CRF rear muffler mount tapped hole.
I heated & bent the rear brake lever in 2 places to clear the clutch cover. Easy & fits perfect now.
A few things I'm still hoping to resolve better are:
* Air box to carb boot: my '88 cylinder has a longer intake flange which makes the carb hit the shock spring when using the OEM rubber carb to reed intake boot. I saw on here that a RAD valve has a slightly different angle & provides just enough difference to solve this. I got one & it did, but with the longer intake flange on the cylinder & matched with a '99 cr250 air box boot (also recommended here), it didn't work. I ended up shortening the neck of the RAD valve as far as I could (3/8") to compensate, It made it better, but the air box boot still could be ~ 1/4" shorter to make it perfect. Right now, the middle of the boot squeezes together upon assembly just enough to cause me concern about air flow restriction.
Anyone know of a slightly shorter boot than a 99 cr250?
* As you all know, the water inlet is on the back of the cylinder. I replaced the '88 clutch casing which was pitted with a later model that has the vertical water inlet. So now I'm hoping to find some info on a water hose that would fit to the back of the cylinder without having to use a 45 deg elbow. Any info on this would be appreciated.
* I'm also looking for feedback on how much easier a Magura hyd cluch kit will make my lever pull. I ordered one last night....
* Rear wheel dia: I've always loved my IRC M5B 140/80-18 but see that they're much narrower for the 19" wheels. What are you guys using to hook up in loose to intermediate terrain? 18" vs 19" & tire recommendations ???
* CR500AFC graphics kit to fit the CRF250 shrouds ?!?!?!?!
So again, thanks to all who share their knowledge here & I hope to be able to do the same.
I documented the entire build pretty well with lots of photos so just ask if you want to see something. Here's a few of what I talked about above:
Doner '88 CR500
Shortened this as much as I could
YES, I have a new clutch cover, just haven't put it on yet....
Did my 1st AFC thanks mostly to you guys here that have or are currently doing the same. After poking around here for a few yrs I finally figured there is enough info & hardware out there to help me do the swap pretty quickly (by that I mean little to no trial & error set backs). The info here is really very valuable & I commend all of you for sharing. I hope to do the same.
I'm from NH & mostly ride the power lines around New England. I have an automotive mechanical & machining back round & a fairly well equipped garage / small machine shop but it's not my source of income....hobbies only (man cave). I can machine my own parts when there are no other options which makes things much easier.
I started with an '05 CRF250 & adapted my beloved '88 CR500 (that I've owned for 20+ yrs) engine into it. After reading a lot of your threads, it became apparent that the Gen 4 is one of the more involved conversion approaches & adding to that an older 500 engine made it bit more challenging. Although not as common, there is still info on my combination here on what I'd run into with the older engine.
I have PNs & sources for everything I bought so please just ask if you wanna know.
I bought the kit from CP500 & his parts AND support are high quality. I'm equipped fairly well to do all the fab work but had to find a good welder to make my alterations permanent. I started this on 4th of July weekend & just fired it up for the 1st time yesterday. All seems ok & will take it for a real ride this weekend.
I used a combination of many of your all's ideas & the build went fairly smooth. Some of the issues I ran into weren't really talked about that much here so I had to just do What I thought was best. (Yeah, I should've created my account & asked a few questions earlier, but I figured by the time I got a response, I'd already be past the issue).
I decided to make my own rear engine mount collars rather than boring out the case & went with everyone's suggestions for the spacers. they work perfect.
I elected to go with left & right radiator inlets as opposed to a single outlet mod at the head. I got the hoses from Australia as recommended in one of the threads here. For me, it's a much cleaner approach & the hoses can be cut to fit perfectly.
I used a couple of Ebay/China extra capacity radiators & although they seem like they'll keep the 500 cool, and they seem much more rugged than the Honda rads, I had massive interference with the new FMF Gnarly pipe on the right side. I had to carve a pretty good chunk out of the bottom corner to make it fit.
I elected to use a rear pipe mount as opposed to some saying it's not needed. I also had to cut & reshape the pipe into my silencer a bit to make it fit with the original CRF rear muffler mount tapped hole.
I heated & bent the rear brake lever in 2 places to clear the clutch cover. Easy & fits perfect now.
A few things I'm still hoping to resolve better are:
* Air box to carb boot: my '88 cylinder has a longer intake flange which makes the carb hit the shock spring when using the OEM rubber carb to reed intake boot. I saw on here that a RAD valve has a slightly different angle & provides just enough difference to solve this. I got one & it did, but with the longer intake flange on the cylinder & matched with a '99 cr250 air box boot (also recommended here), it didn't work. I ended up shortening the neck of the RAD valve as far as I could (3/8") to compensate, It made it better, but the air box boot still could be ~ 1/4" shorter to make it perfect. Right now, the middle of the boot squeezes together upon assembly just enough to cause me concern about air flow restriction.
Anyone know of a slightly shorter boot than a 99 cr250?
* As you all know, the water inlet is on the back of the cylinder. I replaced the '88 clutch casing which was pitted with a later model that has the vertical water inlet. So now I'm hoping to find some info on a water hose that would fit to the back of the cylinder without having to use a 45 deg elbow. Any info on this would be appreciated.
* I'm also looking for feedback on how much easier a Magura hyd cluch kit will make my lever pull. I ordered one last night....
* Rear wheel dia: I've always loved my IRC M5B 140/80-18 but see that they're much narrower for the 19" wheels. What are you guys using to hook up in loose to intermediate terrain? 18" vs 19" & tire recommendations ???
* CR500AFC graphics kit to fit the CRF250 shrouds ?!?!?!?!
So again, thanks to all who share their knowledge here & I hope to be able to do the same.
I documented the entire build pretty well with lots of photos so just ask if you want to see something. Here's a few of what I talked about above:
Doner '88 CR500
Shortened this as much as I could
YES, I have a new clutch cover, just haven't put it on yet....