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User avatar
By Davedup
#90355
Hi all, having replaced the timing and distributer chains and given the SM fresh oils all round I finally got to take it out today.
Starts runs really well but when I got back I noticed some puffs of smoke coming from the breather from the primary chaincase.
The engine breathes quite heavily from the end of the crank through the chaincase and I've just fitted the proper metal breather pipe which vents above the chain (previously was a plastic pipe and union). I've always had a bit of ATF blown out but never smoke before. It doesn't smell like burning oil or burning electrics but smoke is almost sickly sweet. I wonder if it's burning AFT?
My question is, have I used the wrong ATF in there? I've not used this one before and was given a large can.
Bike is sweet and hasn't done this before! Only thing new is the oil, chains, breather and ATF!
Dont seem to be able to upload images at the moment it is MVATF
https://www.commaoil.com/passenger-vehi ... s/view/180
User avatar
By Davedup
#90361
Bullet Whisperer wrote:
Tue May 26, 2020 6:54 pm
I would use 20 / 50 mineral. I see you say you also have a Crusader - for Pete's sake don't put ATF in the primary case of that one!
Not even I'm that daft.
Thanks Paul.
By Jools G
#90411
I've been using ATF in the primary case of my Constellations for years and never had a problem.

Smoke has never come out of the breather on my bikes, and if it's coming out of yours, I would suggest that something is getting very hot inside. Neither should you be getting ATF blown out of the primary case breather for that matter (I'm assuming that you haven't done the 'big breather' modification to your engine if the crank is still fitted with the mainshaft breather?).

I'd be inclined to take off the cover and have a look inside to see if anything is rubbing/binding. The chain does of course run over the metal slipper chain adjuster, and heat is very definitely generated at this point - to the extent of causing sparks. There have been rare cases where these sparks have ignited the vapour inside the chaincase (if the wrong oil is used), the resulting small explosion being enough to blow out the rubber sealing strip.
User avatar
By windmill john
#90412
Best to be thought an idiot than to open one’s mouth and confirm it..... but here goes.

I’m new to RE, had my 350 Bullet for a year; 2002 model.

Can you tell why not to put ATF in the Crusader primary. I like to increase my knowledge thanks. I’m guessing Crusader primary case shares oil with engine?


John
By Bullet Whisperer
#90413
Hi John, yes, the Crusader type engines share engine and primary case oil, but the gearbox oil is still separate. As for this almost obsession with ATF, I have never used the stuff in anything, even our very successful RE 350 racer uses 20 / 50 mineral oil in its primary case.
User avatar
By windmill john
#90415
Thanks Bullet, Paul I think.

I put ATF in my primary due to a lot of recommendations. No scientific study, just following a trend I guess.

I recall a number of years ago, being recommended to put it in my forks. Can’t recall what bike it was.

I am a member of a BM forum and there are lots of sage comments there about certain things. But without all this shared knowledge and especially the tips, where would we be...

I remember in 1978 having to write to Motorcycle Mechanics with a question. Of course it took a month for an answer; times they are a changing.



John
By vince
#90416
Hi, just as an aside the stories of exploding primary cases originated because people were running paraffin and oil mix in an attempt to stop slipping clutch. Vince
User avatar
By Davedup
#90425
Jools G wrote:I've been using ATF in the primary case of my Constellations for years and never had a problem.

Smoke has never come out of the breather on my bikes, and if it's coming out of yours, I would suggest that something is getting very hot inside. Neither should you be getting ATF blown out of the primary case breather for that matter (I'm assuming that you haven't done the 'big breather' modification to your engine if the crank is still fitted with the mainshaft breather?).

I'd be inclined to take off the cover and have a look inside to see if anything is rubbing/binding. The chain does of course run over the metal slipper chain adjuster, and heat is very definitely generated at this point - to the extent of causing sparks. There have been rare cases where these sparks have ignited the vapour inside the chaincase (if the wrong oil is used), the resulting small explosion being enough to blow out the rubber sealing strip.
Thanks Jools, the reason it blows a bit out is that it has been fitted with an inner primary chaincase that isn't the correct one. The breather on the top has been added and put a long way forward right above the crank sprocket, consequently a get some splashes which get blown out of there but only when topped right up (to the drain bolt level)
I've replaced the fluid with some mineral and no smoke, it was the synthetic smoking at relatively low temperature.
Just put 60 miles on and no issues now.
Cheers
Dave

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