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Hello I just changed the oil for the first time on a used bike that I just bought. Reading in the Clymer manual I tested to see if the oil filter bypass was working in the tube. Pressing it I could not get it to move at all and the spring didn't seem to move at all. What should I do? Replace the tube or is it ok to run it like this as it just doesn't allow the filter to get bypassed? Thanks
 

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Little risk (although should be fixed); with a reasonably fresh filter, all oil will be filtered. Only essentially complete filter clogging (an unlikely event) opens the bypass valve.

The oil circulation gurus may correct (one hopes, minor) inaccuracies in the above sentence! :)
 

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The tube has two sets of cross-drilled holes.

As long as the set of cross-drilled holes near the smaller diameter end are closed by the plunger, the oil will be filtered.

I would not run it long-term with a non-functioning bypass tube. Either fix it or replace it.
 

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These are common pieces to replace as many get mistakenly thrown away with the old filter. A local dealer, ebay, Amazon, or online bike dealer will have them.

Sent from my SM-G930V using Tapatalk
 

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Good to know! I will replace eventually when I can. Thanks for the response
I'll suggest that you just need to push the internal plunger from the Stepped End just a touch harder or tap your screwdriver or punch lightly. Once it comes free, rinse in solvent and test push again. Will probably work like 'magic'.

It is actually a 'Cold Oil By-pass Valve'. It allows the cold oil to equalize the internal pressure before the cold oil crushes the paper filter media.
I explained it to Damocles and others a few years ago, as read here,
http://www.klrforum.com/136962-post28.html

If an oil filter was to get so plugged up with metal particulates or mud & sand from being submarined that we need to rely on the oil filter by-pass valve to lube an engine we would know we had bigger problems!
 

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"Cold Oil Bypass Valve?"

Maybe so, but . . . this guy mentions opening the bypass valve only when the oil filter is, "chocked" (choked).


Maybe the bypass valve opens in either/both instances (cold oil and filter "chocked").

Bob, the Oil Guy corroborates the premise, mentioning three circumstances opening the bypass valve:

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The Bypass Valve

Under ideal conditions, the bypass valve will never open. When it opens, the oil by passes the filter and goes on through to the motor, obviously unfiltered. It is a safety valve. However, in real operation, it opens often.

One example is when you start the motor when cold. The oil is thick and does not pass easily through the filtration medium, thus building up to a high pressure drop. So, the bypass valve opens to prevent oil-starvation of the motor. How long it stays open is dependent on how cold the oil is and how long it takes to get near operating temperature. When the pressure drop across the filtration medium drops below the bypass valve setting.

Another example can occur when the motor is fully warmed. At idle, the oil pressure is about 15 to 20 psi, and the pressure drop across the filter is about 1 or 2 psi. You take off towards the redline, and quickly build oil pressure. During that full-throttle acceleration the pressure drop across the filter will exceed the bypass setting, and send unfiltered oil to the motor, until the pressure across the filter has time to equalize. During a drag race, shifting through the gears, the bypass will open several times.

A third example, which you should never experience with frequent oil and filter changes, is when a filter becomes clogged. A spin-on filter can commonly hold 10 to 20 grams of trash before it becomes fully clogged. The bypass valve opening is the only way to keep the motor from becoming oil-starved if the filter becomes clogged.

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And some really stupidly "engineered" spin-on oil filters have NO bypass feature what so ever!

And Kawasaki uses them on some of their ATV's & side-by-sides which get used in sub-freezing temperatures! GO FIGURE!! I substitute the bypass type oil filter on all of Them!
 

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And . . . Honda manufactured MANY small engines with . . . absolutely NO REPLACEABLE OIL FILTERS at all! (Not a problem, I think, given reasonable oil drain-and-fill intervals, on the engines so manufactured.)
 
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