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TB108 saga continues....pics this time

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#21 ·
thorwarrior915 said:
Jason, when is trouble shooting ever a walk in the park?? I dunno how they do things down there in Maryland...hahaha.
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Well see here in Maryland when things dont go right we just smash the thing we are working on to peices. Then we duct tape it back together and sell it on ebay so we can buy new parts.





Errrrr wait does this post fall under your definition of postwhoring? oh well send me a virus or something lmao
 
#23 ·
been studing your pics eysterday @ 930 pm you posted a digram, im suspecting the 17 mm bolt that holds the tensioner arm, in your photo tonite i think im seeing a washer under the head of that bolt or its wear from your socket head that bolts threads dont go all the way to the bottom of the head and there appears to be a guide or spacer on the back of the tensioner arm if you over tourqe the 17 mm or have a washer on it the arm cannot move up and down quick check of my theory pull the tensioner rod and see if you have free play in the arm..another thought the spring on the tensioner rod correct one ? not binding ?? hope this helps good luck!! tryin to win my six pak back !! lol :)
 
#25 ·
i got it



its those gd mexican leprachauns!



haha,eh,i already gave you my input on this in the last thead,and it didnt work

i got a friend thats a realy motor guru(like,honestly,youve never seen someone who can pull stuff off the top of their head and it be correct,like this guy)



ill link him to this thread,post his reply for ya

other then that...start tearin it down and checking EVERYTHING
 
#26 ·
Mx823 said:
i got it



its those gd mexican leprachauns!



haha,eh,i already gave you my input on this in the last thead,and it didnt work

i got a friend thats a realy motor guru(like,honestly,youve never seen someone who can pull stuff off the top of their head and it be correct,like this guy)



ill link him to this thread,post his reply for ya

other then that...start tearin it down and checking EVERYTHING
Click to expand...
Let me guess who that friend is...Its Steve isnt it?
 
#27 ·
First take a look down the passage that the timing chain runs it should be perfectly straight. Also it could be the Gaskets are too thick causing the Chain to be too tight...Its got to be something along those lines Or its a Manufactors problem in the Cases or tension arm.



If planet mini members can pull together and come up with some Used cases, cam tensioners oil pump gear new Timing chain..All the parts I will Rebuild the Motor NO CHARGE. Shipping cant be more than $50.00 round trip



Later...OLDSCHOOL
 
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#28 ·
Check your oil pump

Check your oil pump to see if it is binding. Also if you installed a new pump did you drill the case? If you did not drill the case the pump may be deadheading. Is the passage from the pump to the cylinder clear with no blockage? As I recall there is no way for this pump to relieve itself. If the passage to the head is blocked this would cause the pump to build pressure but have no place to pump to. This would cause a dragging of the oil pump drive sprocket because the pump is deadheading. The cam chain would then be drawn so tight because it is trying to over come the oil pump. Something has to go so the rubber peels off the sprockets and the tensioner plug is also damaged. Also check head and cylinder for a blocked oil galley. If you have a spare oil pump drive hook a drill up to it to see if the pump pulls the drill down beacause of a blockage. Check your pump for blockage and also make sure that the screen on the pickup side is not blocked or the oil pickup to the pump is not blocked. The pump may even be trying to drawn a vacum and not pumping at all. This would still cause the pump drive to apply drag to the chain which would over tighten the chain. Hope this will help you.
 
Discussion starter · #29 ·
I'm almost starting to think the case is flawed. I have another stock 50 bottom end i could swap the TB108 parts into. If i swap this stuff, and it still does it with a new bottom end, we will know that i am just a shotty mechanic.



Right now the motor pumps oil vey well. I actually put a washer on that long cam cover bolt by mistake after the last rebuild and it was big enough that it just let oil flow out of the head. This was stupid at the time, but it might be handy in the future to see if a pump is working good? Would the oil pump work at all if that shaft and sprocket were messed up? The oil pump sprocket turns over fairly easy too considering its attached to a pump. I guess what i'm getting at is, can anybody actually explain to me how the oil pump sprocket or shaft could have anything to do with the tensioner system?



*Edit- I was writing this before i saw minichopperfans reply. A lot of the same still applies though. The pump is pumping fine, I drilled out the passage, its getting oil...not pumping air. And here is how I see this. Imagine the front cam sprocket and the rear cam sprocket(on the crank). If the chain has a very high load on it, the chain will be seen as a straight line between the sprockets. The cam tensioner should be able to deal with the chain being a straight line just fine. There is enough clearance for the wheel to move up that high and still keep adequate pressure. If there was a super load on the chain, it would start to stretch out and throw the timing off you would think.
 
Discussion starter · #30 ·
Holy crap...I just went out to look this motor over again, pulled the stator cover off, and found this!!



Image




See, what i think is happening is that we keep riding through water or snow....then thats when stuff really goes down!



Image




Don't think I dont appreciate everybody's advice...i'm just so sick of fighting with it, this was a cheap laugh.
 
#32 ·
I thought Id contribute to this thread. I went out, and tore off my stator from my Z50 and took a look at my cam chain tensioner. I have an 85cc kit in it, so its not quite a 108, but it does haul around 210 lbs. Also my chain tensioner is manual, but i have it adjusted correctly. This is what mine looks like:



Image




It hits more into the centre of the tensioner rather than the outer corner which your seems to do. I do have a little dent into the rubber, but it is 30+ yr old rubber. To me, it seems your cases are flawed. I dont see how it can be attributed to the oil pump gear that much. Also, your tensioner drum thingy (that holds the spring) seems to be way higher than mine.



If we can more comparison shots between newer crf50's it would be helpful to get Austin's problem solved.



Hope this helps any.
 
#33 ·
yeah if you compare the to its like thors is like bent or something becuase its not hitting at the same place as SprNtrl's is.
 
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Discussion starter · #34 ·
the one on austins 108 looks different because we filed some of the material off the arm, trying to account for the chain having too much tension on it. Fatcaaat recommended trying it in the last big thread. I agree, that we would probably be better off going back to the correct length/style but after trying 2 brand new arms, I thought "what the hell...lets try something new".



SprNtrl- Thanks for going through the hassle of tearing your bike apart to get that picture. I appreciate the effort! I have a new one of those arms, and the old manual tensioner rod (like yours) coming in the mail.



Its a waiting game now...
 
#35 ·
thorwarrior915 said:
the one on austins 108 looks different because we filed some of the material off the arm, trying to account for the chain having too much tension on it. Fatcaaat recommended trying it in the last big thread. I agree, that we would probably be better off going back to the correct length/style but after trying 2 brand new arms, I thought "what the hell...lets try something new".



SprNtrl- Thanks for going through the hassle of tearing your bike apart to get that picture. I appreciate the effort! I have a new one of those arms, and the old manual tensioner rod (like yours) coming in the mail.



Its a waiting game now...
Click to expand...
No problem, It wasn't too much of a hassle.
 
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