| Author | Message | ||
     Andersonhdj |
At the risk of upsetting the status quo i feel the need to broach this one - i have an xb9 with suspect crank, well, admittedly i am not very familiar with these motors as yet BUT, I had a curious oil pressure situation that begged investigation. When i cut the motor, the oil light would take anything up to 3 mins to come back on, this led me to believe there may be a blockage, pulled the filter and realised that the adapter was loose, so i unscrewed it suspecting a possible faulty non return valve, anyway, after it drops into my hand i inspect the rubber bung and see clearly a skew seating pattern on it, now my suspicious mind tells me that possibly this valve had been fitted the wrong way round by the previous hamfisted twit that also ground the hex on the rear sparkplug. So i check the toyota yaris filter that i'v got, it has a built in valve, as do most decent filters used on engines with OHC's, decided to fit the filter without the rubber bung/valve as a test. start her up again, cut the motor, instant light. Now in my fiddlings, and here is the cruncher for me, unless i am dumb, blind, stupid or just not experienced enuff with thsi particular motor, the Oil pressure sender is upstream of the filter, which means that a restricted filter isnt going to show up until it's done some harm. Yes i know that should never happen but, it seems there is a propensity for crank failures here? Comments please. | ||
| Reepicheep |
Crank failures on XB9's range from exceptionally rare to unheard of. Unless you are racing (running at absolute peak RPM for extended periods of time). It's the XB12's that are killing cranks. And even then, the failures are rare and clustered, suggesting metallurgy problems rather then a universal problem. Don't get me wrong, the bikes we have tracked with crank failures include two that rolled off the line within 30 bikes of mine... so it happens and I am interested. I don't see your connection to a crank problem and the oil pressure problem though. I'd be looking at your oil pump and oil pump pinion gear first. Also, did you fill the oil filter before you put it on? If you don't, the oil pressure can take a very long time to come back up. | ||
| Andersonhdj |
It's not that i did'nt have pressure and yes, i did fill the filter,it's not a loss of pressure but rather a retention of pressure for an unreasonably long period of time. Maybe you did'nt understand my explanation. I'v also checked the lines and the oil cooler for blockages, all clear.Anyway i have resolved the issue as detailed in my previous post. The noise sounds like a shot roller which can only be the big end and i am looking for a reason, it's what i do with any motor failure, there has to be a reason. I need to mention that tho i am not familiar with these motors i am not considered to be a rank amateur. Anyway this was just more of a heads up and to question the sender unit position which does seem a little odd to me, i suppose once i get around to gutting it i will know the answer anyway. | ||
| Buelliedan |
I strongly suggest you call Dark Horse Crankworks (Hoban Bros) in WI to help you with your XB crank. they are the best and they will do it the right way. | ||
| Andersonhdj |
I am in South Africa, due to cost and logistics, it's not a viable option.Yet | ||
| Anonymous |
There is a new crank company the crank builder at Darkhorse started, looks to be a little less costly. Sounds like he's done a few XB cranks. | ||
| Alex |
Andersonhdj, the rubber bung with the spring behind is a check valve which opens at about 4-6 psi. Logically when You shut down the engine it will close and "trap" some oil pressure in the filter, oil lines, oil cooler back to the oil pump. The pressure sensor is located in exactly that part of the system and it may take some time until the oil pressure comes down due to bleed off through the oil pump. If You have a very "sensible" oil pressure switch it may take some time too until it activates the oil light again. Removing that check valve opened the way from the oil pump all the way through the engine so if You shut down the engine now oil pressure wontīt be trapped in the filter compartment any longer as oil can bleed off through all and every "hole" in the engine (like connecting rod bearing, pinion bushing and so on). That clearly shows that there isnīt a blockage in the engine. I canīt really say if You have a crank problem but Iīd like to say that You donīt have a blockage in the engine compartment. Get that check valve back in (the rubber bung needs to seat against the oil filter adapter with the spring beeing above it). You can easily confirm that the check valve keeps up the pressure in the filter compartment by just doing this: shut down the engine. If the oil light doesnīt come up just loosen the oil filter until it will spit off some oil. Then the oil light will show up at once. Regards Alex | ||
| Andersonhdj |
Alex, point taken, once i have opened her up and determined the cause of the noise, shot crank or whatever, i'll take the appropriate action. At this time however, i'm not running her and in any case, the filter is made with a built in check valve, specifically for oil retention, as used in the Toyota Yaris motors and other OHC motors, so i have faith in what is happening at this point in time. Right now i have 2 other bikes and my Lotus 7 to finish off, so i have'nt stripped her yet. Hopefully near the end of the month i'll get to it! | ||
| Buelliedan |
Anonymous, Why are you posting this as a anon? |
