Crankcase Sealant Suggestions

Shipper

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Been through the Tech pages plus see that Hans Pahl recommends that Dirko Red paste. Never been a fan of that messy stuff and hate the colour. Is Permatex Aviation Form-A-Gasket in minimal application a safe way to go?
 
Been through the Tech pages plus see that Hans Pahl recommends that Dirko Red paste. Never been a fan of that messy stuff and hate the colour. Is Permatex Aviation Form-A-Gasket in minimal application a safe way to go?
That's my go to. Use a q tip for better control.
 
I use Dirko to seal small engine crankcase halves. Good fuel and heat resistance. Yes its messy and sticks to everything but that’s what its supposed to do. If you don't like the red I also have gray. On the bikes I use 3 Bond.
 
K, now that I have spent the wad on rebuilt crank, cam, bearings and blasted my casings etc., I notice this chipping of the coat material inside the casing. Noticed it around the kick start recoil spring some time ago but didn't pay it much attention. Going to close the bottom end this afternoon regardless - no loose chips in site. Any comments?
 

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1st pic are just casting flaws at the alum/steel interface.... normal. Just ignore 'em.
Can't tell what's up in the second pic. It's too small to see what you're concerned about. Shoot again?
 
K thanks Jim. The first pic shows how that (peeling?) of the surface coat has happened a little bit in the far left oil feed to the crankshaft bearings. Not that concerned about it as it appears to have good airflow and no pieces come dislodge when cleaned with brake cleaner and a swab. The next photo is out of Pahl's book which identifies the oil outlet in the crankcase (photo 2-66). Is that the same oil port as identified in(photo 2-65) far right? Reason I ask is I get no airflow from the any crankshaft bearing seats other than whats identified in photo 2-65. The centre feeds are obviously free and open.
 

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Reason I ask is I get no airflow from the any crankshaft bearing seats other than whats identified in photo 2-65. The centre feeds are obviously free and open.
'bout all I got for ya is Pahl's book is well written and well vetted. If you're getting flow where he says you should, I'd call it good.
 
The next photo is out of Pahl's book which identifies the oil outlet in the crankcase (photo 2-66). Is that the same oil port as identified in(photo 2-65) far right?
Yes, looks like it. Is that the far left bearing carrier? There should be flow there.
 
Well, sitting on the bike, there is no flow in the far left carrier holes but that makes perfect sense because there are no oil ports in the large bearing race at that end when seated in the carrier. There is flow in both front and back ports for the centre bearings and again, makes sense as there are oil ports front and back in the centre bearing races when seated in the centre carriers. My problem is on the far right carrier. There is flow from the front oil port but nothing in that rear hole and it doesn't look like there ever was. There are oil ports front and back of the far right bearing race when seated in that carrier. Why wouldn't there be flow on the rear of that carrier?

Have I confused it all enough? I can go on.
 
After much thought, it appears that the oil holes in the bearing races don't line up with the oil holes in the bearing races anyway. That's my bad not seeing that earlier. Oil feeds into the races through the oil ports at proper pressure and not fed directly into the races from the carriers. Having said that, it still seems odd to me that the rear hole in the far right carrier would be dead ended.

Anybody got any other advice? Bottom end going together first thing in the morning.
 
OK, I just marked up Pahl's image for orientation. We still on the same page?


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OK, just dug up a pic of my cases when I put the bottom back together. Notice the blue masking tape? I taped up the oil passages so nothing foreign got in there. There's only 3 pieces on the crank carriers.



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OK, I was operating from the opposite orientation as if sitting on the bike. Hope you saw my last post. The only remaining issue to me is it makes no sense that the rear hole in the far LEFT bearing carrier (using your drawing above) is dead ended.
 
Gotcha Brother. Answers my questions. Always looking for a reason associated with design particulars. Sometimes there aren't any.

Really appreciate your time and the precise pics just forwarded. Right on topic. Bolting her together first thing in the morning.
 

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Going by Pahl's pic and mine w/blue tape... the forward holes are the only ones drilled for oil. Long as those 3 are clear, you're golden.
 
Reading Pahl's recommendations prior to fastening the lower end casings together he wiselly suggests "last opportunity to check the function of the shift mechanism before closing the engine housings.... The shift claws of the individual gear wheels must be fully engaged in the recesses of the counter-gear wheels."

I can turn the star gear with resistance as suggested in both directions engaging 1 through 4 but five will not engage without manually positioning fifth gear by hand.

Is that normal prior to fastening the housings?
??
 

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Hmm...I reckon you're rotating the transmission shafts by hand as you're shifting through gears; they should all go as the dogs align. How are you positioning 5th differently?
 
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Don't know how you would position it differently once its on the shaft. The claws are all aligned and in their respective groves properly. I just thought i remembered being able to shift through all gears from the star gear on the transmission side prior to closing the housings.
 
Fifth, of course, slides both ways and it might not have the dogs aligned statically in one direction. Shifting gears laying in the upper case is iffy. You get another chance to evaluate once the lower case is installed, using the shift shaft normally, before further assembly
 
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