CR250 Air Box Fix?

[jimt_yz400]

I just acquired a CR250 (someone traded it for my used '01 250F) that is only 3 months old. I was told that the 450F's have issues with the airbox but do the 250's also have the same problem? Do I need to buy the PC1 air box fix or the MX Bonz or can I just reseal the air boot to the air box?
Thx!!

 

[los36]

buy the PC Racing Super Seal. It's about $20.The air leak is between the filter and lip because the filter cage doesn't apply any pressure to create a good seal. The PC thing fills in the gap w/ a neoprene rubber ring.

 

[mikep79]

Go one step better and buy the Twin Air custom filter and aluminum cage. I use it and it seals perfect.

 

[Moto Squid]

I bought the PC kit and like the thicker plate and the 1/4 thick foam for the air filter...what I don't like is that the plate STILL distorts enough to let dirt past the kits thin little rubber gasket (between the airboot and airbox) which is suppose to seal better than Honda's band-aid fix. So I took it apart, threw that seal away and goobbed lots of silicone in there; Haven't had a problem yet. Shame on Honda :|

 

[jimt_yz400]

I also heard real good reports on the mxbonz fix, www.mxbonz.com
Anyone try that fix? Apparently it has two CNC plates, one for each side of the boot seal and you cut off the nubs on the inside of the airbox so the filter can sit flush.

 

[Moto Squid]

wow, I like that idea much better than PC's kit :thumb: Those stupid tabs strip easy and the plate or airbox can still distort enough to leak. hmmm...now my gears are a spinnin on how to modify the PC plate :think:

 

[jimt_yz400]

Squid,
The only pblm is that it's alot more work than the PC fix.

 

[Moto Squid]

time and work...nah, thats a relative thing ;)

...as long as the payoff is worth it

 

[bedell99]

Ok guys, I worked on my airbox and it is totally dirtfree. First buy an aftermarket air filter. (UNI and Twin Air work real well). Next go to PCracing and get there Proseal and PC aluminum plate. Now here is the trick whatever you do don't use the gasket supplied with the kit. In plain english it sucks, plus you have to modify the boot nipples. Instead use honda weatherstripper cement and use that as a gasket. Bolt it all up and no more problems.

 

[bigred455]

I have taken my kx apart before to seal the metal cage to boot rim.In between this area their is a nice adhesive foam piece.Why doesn't honda just do it right and forget about it.

 

[James]

They had it right from 2001 and forward for about 8 years from what I can remember. I ended up installing the 2001 boot, filter mount, and front ring. Lots of work but it is done right. In my opinion, the PC kit isn't much better than the stock setup. If I had to do over, I would probably go with MXBonz.

 

[bigred455]

I was looking at the mxbonz,it doesnt look like they supply the rubber or foam that goes in between the cage and the rim of the air boot.

 

[Moto Squid]

I believe that the plate that goes on the inside of the airbox gives the added seal for the air cleaner. IMO the mxbonz is a better choice, if I did it over that'd be my choice.

 

[h bomb]

My 03 CR250 leaks I just took it apart and siliconed it no more leaks,they sell good silicone at home depot,you don't need anything for the inside just grease the lip real good,on the 03's.By the way if you ride MX throw a 50 on the rear it will help the powerband a bunch.

 

[02'Cr Rider]

Moto Squid, I had the same problem as you with dirt still getting past the gasket seal.I have the PC kit with twin air filter.The plate still distorts with kit,but I fixed it and does not let any more fine dust in that I was finding.I drilled holes in between the original screws and put rivits.It keeps the alum. plate flat,and works great!!!!!!! Try It.

 

[Moto Squid]

I was thinking about that but tried silicone first. Did anyone else with the PC notice that the red plate is too thick on the left side??? It needs to wedge in the "V" of the boot there but really doesn't. I ended up grinding a taper and it fits great now, but I'm not liking having to fix the fix kit in two areas.

 

[marcusgunby]

All these kits that dont work seem a waste of money and time-i drilled a extra screw hole between each std screw location and then resealed it with a sealant, then i had the std plastic cage machined out in the centre so it goes up snug against the airbox, lastly use a twin air airfilter-never any muck at all-cost about £3

 

[jimt_yz400]

marucgunby
You know I think I tend to agree with you and these are good suggestions. I haven't checked but the cage DOES NOT sit flat against
the box? So, you then took some material off of area around where it fits onto the box/bolt ?

 

[whyz]

Originally posted by h bomb
My 03 CR250 leaks I just took it apart and siliconed it no more leaks,they sell good silicone at home depot

I've read somewhere about not using silicone because the fuel will deteriorate the sealer and allow water and dirt to enter the airbox.
Weatherstip adhesive works better because it isn't fuel soluable.
Oh here it is>> EG's Performance Handbook,2nd edition. :cool:

Seems like Honda had this problem in and out of years
since the mid 80's. Whats the deal?

 

[marcusgunby]

It was common practice to remove the original stuff and replace it on pre 90 bikes.

Jimt yes i had about 4mm removed from the area that sits against the bar that holds the cage tight.Anyone with a lathe can do it in about 3minutes.Mine now sits very close to the airbox.

 

[JTT]

Originally posted by marcusgunby
Jimt yes i had about 4mm removed from the area that sits against the bar that holds the cage tight.Anyone with a lathe can do it in about 3minutes.Mine now sits very close to the airbox.

Yeah, but Marcus, why fix it for right for little $, when you can throw good money at it for "trick" parts. :thumb:

 

[ELSINORE_45]

Well all I did was take a heat gun , and heated up the 2 arms that hold the filter cage in place ,bending it towards the carb in take. It only needs to bend about 2mm or so . I Then placed a wrench between the 2 arms ,were filter is held and the other end facing the back of air box .Once it chilled out I remove the wrench,and it was fixed sucked it right up .I did this fix in april of 02 on my 02 cr250 and its been fine ever since.8) Oh yeah you need to remove air boot from box so heat wont distort the rubber ,any ways you needed to do that with out even asking to fix the leak between the two. try it you like it its FREE FIX 8) Thxs ELSI _45