HPI VS stock

[evaneyeball]

So my cdi went bad today and I talked with arlen already and he gave me some things to try and they didnt help so I'm going to call him tomorrow and see what he thinks but I also kinda just want to know what you guys think of the hpi like is it worth it or do I just get a old oem cdi and have something else blow out in a week and fix that and have the new cdi go out idk. Just for shits and giggles. And it was detonating when I was going up banshee hill and I stopped as soo. As I heard it. And I knew it was detonation so I went back to check things out and there was grey sludge in the cylinder.

[havinnoj]

"Trying" another stock CDI (assuming someone has a good one for you to borrow/buy "cheap") would be the easiest thing to test first.  HPI is reasonably priced but I don't know more than a couple people that have ran them.  @coops86250r posted a nice install thread here (https://www.forums.trx250r.org/index.php?topic=8701.0). 

[evaneyeball]

Yeah I cant find one to buy but I'm sure if I look hard enough I can. But i do have one from a 85 atc

[croat1]

Yeah I cant find one to buy but I'm sure if I look hard enough I can. But i do have one from a 85 atc

85 atc250r is the only oddball CDI.  It’s a round plug

Joe

[evaneyeball]

Ok I didnt notice that I haven't torn into it yet and I just got home.

[Hawaiiysr]

i got a ricks you can have. people complain that these have kick back. yes, they do if you dont kick it right but other then that its fine when it is running. The only reason i removed it was because i bought a 2001 CR ignition.
PM me your address and i ll have it in the mail tomorrow morning. 

[evaneyeball]

kinda off topic but i did notice that when it was detonating and it was only up a hill with a lot of load it did lose power and it couldn't go any further if i did try (and i didn't, as soon as i heard it i stopped) it did start to lose power before detonation occurred so do you think i fried it or not, i did notice it was easier to kick over after it happened once. and i haven't taken a compression test before and i didn't want to take the plug out because i was worried about the threads and it coming out again because if threads so bad on me for that but i can take one tomorrow because i probably should change plugs now just for maintenance and i might have to take the topend off it you think i hurt it

[The norm]

Sounds like you are going to be doing another top end..

[desertR]

Sounds like you have problems, not enough octane, too much ignition advance, or plug heat range, lean condition. The grey sludge mentioned is not good. Loss of power is probably a partial seizure of the piston, it needs to come apart. Detonation heard over the pipe, is bad, can melt a piston before you can even hear it.
desertR

[evaneyeball]

Damn it. I guess that that means I'm getting either a new cylinder or sleeve if I have to bore it because I'm already  bored at 69mm or 68.5 I cant remember.

[The norm]

What is your current carb size and jetting? My boys R's both have 38mm airstriker carbs and 48 pilot/175-178 main/DGH needle at the 3rd groove. 13.5:1 compression running 92 octane non ethanol gas mixed 40:1 klotz R50.

[The norm]

You may also be able to hone it and install another piston and rings. Depends on what the cylinder looks like.

[Hawaiiysr]

better that you caught it now. may be able to save the cylinder.

[evaneyeball]

I talked to arlen and he said to take the head off and so I did and its blown even the cylinder and head are gone

[desertR]

People don't understand just how important octane is. On my daily, I run premium, and 50/50 water/meth and that works out to 115 octane. Lots of safeguards on the meth setup (Aquamist) but with 23 lbs of boost, you need it. I run 50/50 as more isn't needed and it gives me another 1/2 second run time, before melting a piston, If the meth fails, and yes, I drive it hard.
desertR