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CRF230F Centrifugal oil filter cleaning problems?

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A local dealer’s parts and service departments recently told me they recommend AGAINST cleaning the centrifugal oil filter in the CRF230F. They said even they try to avoid performing this maintenance, instead adding a type of “detergent” product to the crankcase, draining it, cleaning the other, coarse screen filter and adding new oil; they said that they have used a heat gun to try to help loosen the three filter cover screws, but even then still often find problems with stripping the threads there. They also seem to imply that there are other problems (stripped threads/oil leaks afterward?) directly associated with removing and replacing the right side engine cover to access the centrifugal filter cover. Honda recommends periodic cleaning of the centrifugal filter (using a new right side engine cover gasket and new centri filter cover gasket), though not with every oil change. Of course, Honda DOES recommend to clean the coarse screen filter with every oil change.

It seems to me that the layout of the centri filter would cause heavier contaminants to stay in it even if “flushed while still assembled” with some “detergent”. I wonder if the dealers have experienced thread-stripping problems due to their own ham-fisted practices, or perhaps due to bad practices at the Brazil factory that made the CRF230F, or if there is some design flaw?

Has anyone in TT Land experienced any such problems? Do you have any tips for performing this recommended maintenance? Is there, for example, a trick to holding the filter rotor steady while loosening/tightening the centri filter cover screws?

Edited by BSAVictor

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Sounds like a good question. I was also thinking of cleaning the centrifugal filter on both my 230 and 150.

Jesse

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They're avoiding it because it:s a little more work than replacing an oil filter. No big deal. Follow the instructions in the manual and clean centrifigal filter after every few oil changes.:busted:

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wow, time to find another dealer.

ive had both my cases off a few times, no problems there, just replace the gasket and clean the mating surfaces well and ull be fine

the cen filter is super easy to clean, i did mine after about 3.5 years and there was little to no buildup in it.

make sure you get another gasket for the case cover and a gasket for the cen filter cover.

i wouldnt run any kind of "cleaning" detergent through the motor either, sounds like a bad time.

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I did a lot of research for my 150 and then my 230 about the oil filter, to make a long story short, leave it alone, just change your oil often and thats it.

these bikes are great.

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I mention servicing the centrifugal filter rotor several times here:

Honda CRF230F - A look back <-- linky

Once a year is plenty for me - see the tiny amount of residue.

Click the pictures to supersize.

I have two tools that help removing the phillips screws:

TwistyTools.jpg

The second from the left right-angled screwdriver has the right size phillips head and is great for busting loose those overly-tight-from-the-factory screws. I also have a screwdriver that has a metal rod that fits into the handle and sticks out at right angles - same principle only easier to use.

Lastly, I once used an impact screwdriver on my old XR200R when all attempts with a regular phillips screw driver failed (before I got the tools mentioned above). You tap on the tool with a hammer and it rotates the screw loose (also tightens screws). Amazon.com has them for $15.

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Great tips so far, tho I wouldn't expect everybody to have the same take. I think I'll go for cleaning the centri filter, but would still appreciate seeing any further input from y'all. I have some of the same and some similar tools, RAMZ! THE RIGHT TOOLS IN THE RIGHT HANDS GIT 'ER DONE!!!!!! I'm also going to look for a known-brand (micro?) torque wrench to use for those delicate fasteners (my current wrench doesn't go that low, only to 5 ft-lbs and metric equivalent, etc.). One can go by "feel" on a lot of fasteners when you have worked with the same ones for awhile, but those tinier screws don't give ye a 2nd chance, right?:lol::bonk::busted::busted:

Edited by BSAVictor

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Same oil system as the XR185/200 series of two valve engines. The threads on the cen filter do not strip, it is the Phillips slots on the screws that strip because the they were installed too tight or an impact driver was not used. Have said that I've found that mechanics over tighten the screws, I've had to use a left hand drill and/or an extractor on many.

On high mileage used engines I've found a lot of debris in the filters so they do need to be serviced and I think the amount of debris indicates a lack of service. The debris also indicates that frequent oil changes are important to keeping the crankcase clean and reducing the load on the filter. So I vote for more frequent oil changes than Honda specs, I change every 5-10 hours for trail riding. And based on my results I think cen filter cleaning can be extended to one or two years, but I don't usually ride in real dusty conditions so YMMV.

I agree with having the two gaskets handy but with care and the application of grease you may be able to reuse the gaskets several times. I also suggest having 3 new screws handy in case the Phillips slots get damaged.

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XLNT IDahs, Chuck! I'll also go for 3 xtry screws on hand! I use zip lock bags to keep such spares/batteries separate, "fresh"/uncorroding the device, and known--I also toss in said bag a post-it note to ID the part for when I forget what the gizmo in the bag was fer.

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never heard nothing bad about it,just about to do mine on my 230.

Edited by Sookerider

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I've ordered the screws and gaskets; will post results. Sookerider, let us know how your procedure turns out!

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...................... I'm also going to look for a known-brand (micro?) torque wrench to use for those delicate fasteners (my current wrench doesn't go that low, only to 5 ft-lbs and metric equivalent, etc.). One can go by "feel" on a lot of fasteners when you have worked with the same ones for awhile, but those tinier screws don't give ye a 2nd chance, right?:lol::bonk::busted::busted:

Not many second chance on those small oval head Phillips screws that is why I start with a good quality bit in an impact driver.

Small torque wrenches are available on ebay. here is a 1/4" drive in/lb model accurate enough for those screws. http://www.ebay.com/itm/1-4-Drive-Tool-Torque-Wrench-1-4-Drive-Inch-Pounds-USPS-Priority-mail-you-/120810364389?hash=item1c20dbdde5&item=120810364389&pt=Motors_Aviation_Parts_Gear&vxp=mtr

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Thanks, Chuck4788, but I wanted to feel more like I could trust the tool on those delicate missions. Got applicable wrench -Craftsman at Sears on special for about $55 out the door. Just don't want to take as much of a chance on something like that.... Guess even "good" wrenches can be off a bit, so still have to be careful on torquing....

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Maybe a delicate mission but almost any torque wrench will be more accurate than free hand. I meant to imply a cheap non-certified torque wrench would be better than using a hand wrench or screwdriver, and most home shop torque wrenches are not certified. And Sears does sell good torque wrenches for home use.

The little oval head screws can easily seize so good initiative on your part to attempt avoiding problems.

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In the Honda Service Manual, the only torque values I find for the right crankcase cover bolts might be in a standard torque values table. Which dimension is referenced where the table reads, e.g., “8mm bolt and nut”? Does it refer to an 8mm outside thread diameter, or head diameter between the open-end-wrench surfaces, or...? The right crankcase cover bolts measure 8mm between the open end wrench surfaces, plus a small flange that makes the overall diameter some 10mm between the flange extremes.

A little help TTers, on what the proper torque for these bolts is, and or on how to interprete the sizes given in the torque table?

(Yes, thanks, I know to observe multi-step criss-cross loosening/tightening of the crankcase cover.)

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Unless you have something catastrophic happen such as a rubbing cam chain, I wouldn’t worry too much about cleaning the centrifugal filter. I have a 1974 Honda XL350 that has the same filter system. In 2004 I took it apart to clean it. It really didn’t need cleaned. 30 years and it was basically fine. I may have gotten half a teaspoon of stuff out of it. Probably good for another 30 years.

I cleaned the centrifugal filter on my 2003 Honda CRF150F in 2010, seven years into it’s life. The only reason I did it was because I was there, changed the clutch plates. It looked like a new part inside.

Change the oil religiously, every three tanks of fuel, and you shouldn’t get a build up inside the centrifugal filter.

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I agree with Mike38's post but if you buy used you just don't know the condition of the engine. And I have found a lot of debris in purchased engines. Your owner's manual will have a maintenance schedule for the filter. My previous post suggested that the mileage value speced by Honda could be extended to a two year interval. Based on Mike38's experience and recommendations filter cleaning may be many years.

Torque values in tables are for the bolt shaft size, not the wrench or head size. Honda likes to use 5, 6, 8, and 10mm fasteners. The wrench sizes for each of these fasteners is larger than their nominal size. Values in a generic torque tables can be higher than Honda specs for a fastener so check the Service Manual.

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Thanks, Chuck, but again, the torque table I'm writing about here is in my Honda ServiceManual for 2003-2006 CRF230F. There is NO torque spec given in the Manual section devoted to removing and replacing the crankcase cover, only DIRECTIONS on removing/replacing the cover. People who have this Manual can look at it to verify what I'm writing.

I will measure the bolt shaft when I remove it from the engine, and try to relate the shaft size to the Honda torque table in the Honda Service Manual.

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Without exception, every bolt that holds a case cover on or that joins the center cases is an M6. M6 bolts are 6mm in diameter and unless specified otherwise, require 7 ft-lb of torque. None of them are specified otherwise. And that's with dry threads, bolt and case.

You cannot use a 3/8" or 1/2" drive torque wrench which is rated in ft-lbs to apply 7 ft-lb of torque; neither size torque wrench of any make is accurate at the low and high end of their rated scales (discount 20% on each end). You can buy a 3/8" or 1/4" drive torque wrench rated in in-lbs and use a setting of 84 in-lbs to torque the M6 bolts (7*12=84).

However, you will find that about once per 100, you will still strip a bolt or case thread. This is because the bolt and/or the case threads are not dry and you will be applying too much torque due to the oil (or other fluid) residue. It's easy enough to clean the bolt threads, but getting the case threads dry is another matter.

So what's the solution?

Here's what I do. I use the in-lb torque wrench set at 6*12 = 72 in-lbs. Then, I do a last pass using my hand to apply the final torque through a 1/4" drive standard ratchet. I add just a bit more torque until my hand says - that's enough. I want to feel the bolt turn ever so little and then tighten up. It's a very noticeable feel. After doing this a while (several years in my case), you can dispense with the torque wrench and just do it all with your hand and a 1/4" drive ratchet or t-handle. You can even get the right feel through a 6-point box-end wrench (avoid 12-point and never use an open end wrench if you can avoid it).

And yes, I still strip a case thread now and then, maybe once every 4 years or so. :banghead:

So on my next oil change, I'll probably strip both oil filter cover bolts. :cheers:

Note: Page 1-14 of the Honda Common Service Manual shows:

"It is important to oil the threads of specific fasteners when instructed to do so in the Model Specific manual. Oiling the threads of these fasteners ensures stable fastening tension in critical areas. No other bolts besides those specifically pointed out in the Model Specific service manual text require oil on their threads."

From the foregoing, I infer that the case threads must also be dry. DUH.

Bold emphasis mine.

Lastly, this is all MHO. :lol::)

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Xlnt post, Ramz!

My new wrench reads in Newton-meters and inch-pounds in the range applicable for these fasteners---but vulnerable to the 20% inaccuracy-at the-low-end you mention.

Your stepped approach toward the remaining-liquid-residue-on-threads issue makes a lot of sense (how would the average person get "all" liquid out of the case threads without leaving lint or introducing dirt or solvent where you don’t want it –via compressed air, q-tip, rag corner, for example, etc., etc.?) and your careful, experience-developed, hand-feel tightening “finish” is consistent with what I’ve found in my decades of shade-tree work.

The standard torque value in my Honda Manual reads: “6mm bolt and nut --- 10 N.m … 7 lbf.ft” and “6mm flange bolt (8mm head; small flange) --- 9 N.m … 6.5 lbf.ft”. I haven’t yet removed the bolt to measure it, but this all looks to me like it’s consistent with what you wrote. Hopefully in the next week I can put this to use and report back!

Edited by BSAVictor

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