Air Filter Whoops... ideas?

[Toothmech]

Hi all, kinda made a bonehead manuever with my '97 CR250. It had a Uni air filter on it when I bought it, so I took it apart and cleaned it with Simple Green (didn't work very well) and then re-oiled it with Uni Air Filter oil. I noticed however, that there were two filter in there, one looked like what I am used to seeing from Uni (color, name, larger pores, etc.) and the other one (inner) looked like the factory one (in the past, all the uni filter I have had on other machines only had one filter to them). But I reassembled it the way I found it and rode it. Ran alright, but had black spooge comin' outta the silencer, and was flat on the top end. So I take the inner filter out, and the thing runs awesome (textbook tan plug, power everywhere). Then a month or two later, I find out that the uni filters have two layers like that for the dirt bike. In total, I rode it maybe 5 hours in that condition, only about 2 hours of the riding was in dusty conditions. My question is: Do you guys think I screwed anything up in the engine top end bad enough to warrant a prophylactic rebuild (it still seems to run just fine, pulls strong, and as for noise from piston slap, not sure exactly what that sounds like)? I have a new filter for it for next seasons riding, and will find something better to clean it with (any ideas?), but for the time being I am inclined to just let the piston go and keep riding it until I get something more definite out of the motor as far as problems are concerned. Any input would be appreciated guys, and sorry about the long post.

 

[buffmaster]

First, how long has it been since the last rebuild? If it's been awhile, just do it anyway. Should be done every six months or so if you just ride it on the weekends or so, more frequently the more you ride. Not a cut-n-dried rule, but it kinda works. I'd check the air boot to see if there's any telltale signs that you got some significant debris in there. If that's clean, check the carb and the reeds. You might be ok. Someone else on here might have some better ideas though.

 

[Toothmech]

Hey Buffmaster, nice to get a reply. Off the subject, but I'm from Houghton Lake, MI... not far from you. I live in central IN right now, but that's only temporary. Where do you ride up there? I get back home a couple times a year to ride, usually on the ORV trails. Anyways, I have the bike apart right now, and will get to the carb and motor this week, will check the carb boot, etc for debris. The top end was new when I bought it, along with the bottom end, so I think it has less than 10 hours on it all told (no state land down here, so riding is pretty erradic). Any ideas of something good and safe to wash the filter in for the future? as I will be cleaning it after every ride from now on. Anyways, I will get into the carb this week, and let you know what I find. Thanks-

Ben

 

[buffmaster]

I've ridden lot's of places up here, but mostly I just ride at my friends place. He's got 120+ acres with some good tight trail. We mostly burn laps on it to get ready for the Hare Scrambles we do. We try to ORV every now and then, but we've usually got races every weekend during the season.

On the filter, I'd recommend something specifically to clean it with. I know ppl, and have done it myself, that use gasoline, kerosene, diesel fuel and mineral spirits. The possible problems you run into w/that is ruining the glues that hold the filters together. Sometimes the harsh fuels won't even harm the glue, but you never know. I recommend No-Toil. I've been using it for a few years and love it. The one thing about it is that you HAVE to use their cleaner. I tried using all the above chemicals on a filter w/No-Toil in it and it was toast by the time I was done. You can use No-Toil on any filter. I've used Twin Air and No-Toil filters and have been really happy with them. I have heard things about Uni filters coming unglued. Don't know how substantial that is, but I have heard it.

Lemme know when you pop back up here during riding season. And keep an eye on the Michigan Trail Riders forum for rides. Maybe we could end up hooking up.

 

[reelrazor]

I have found that regular clean mineral spirits doesn't damage any filters I come across. If it is getting old/dirty/contaminated, yeah, then you can have problems. As far as any damage, a compression check and inspection of the carb/boot like Buff said, plus maybe a look up the exhaust port would help me make the decision.

Nice to meet ya Michigan guys. I am in Cheboygan where I started my own indy shop earlier this year after 19 years of working for others. I have a friend from my San Diego days who will be here for the 6 days of Michigan next year. Either of you ever done that one?

 

[Toothmech]

Hey thanks from both of ya for the suggestions. It's nice to hear from some fellow MI boys around here too. As far the the No-Toil, I have heard great things, but am having trouble locating the stuff down here, any reccomendations of a place to buy it in the Northern MI area when I am back home during the holidays? I will pick some of that up for the new filter. As for the remaining one I have, I think I will use the mineral spirits (thanks razr) to clean it since it looks pretty old and cruddy, then I will just use it to swap back and forth if I don't have time to clean the outer one every time after a ride. As far as the 6 days of MI, never heard of it, but am interested. I have another year and a half trapped in this dump (IN), but after that I'm comin' home, maybe then I'll get a chance to try it. As for the MIchigan Trail Riders board, is that on this forum somewhere, or at another site? Anyways, thanks again for the help guys-
Ben

 

[buffmaster]

'Razor, never done that one. I just started racing last year. Plan on making more of an effort this year. Don't know if I'll check it out this year, but maybe next.

Tooth, the MTR forum can be found right here in the 'Places to Ride, People to Ride with/DRN clubs' forum under the 'Eastern Chapters' folder. As for the No-Toil, check out their web site, www.notoil.com. They've got a list of distributors. You also might want to check out the 'net for dirt bike places. Check MX South first and if they don't carry it, go from there. I know that Chaparral carries it.