Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: adespin on June 20, 2018, 11:20:32 AM
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Yesterday i ordered a new set of silencers from David Silver, K2 version for my K1 as i would like a quieter system and i'm not concerned with the performance drop (I'm an old git of 70) and they are also a damn sight cheaper than the K1's. Has anybody who has bought a new system taken any precaution against internal corrosion? i'm contemplating pouring a quart (thats an age thing) of engine oil into each silencer, giving it a good shake around then emptying out. Does anybody see a problem with this ?
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(https://uploads.tapatalk-cdn.com/20180620/cdf3a5841238e316e3faef9343df8ea7.jpeg)
This is what you’re dealing with internally (HM341’s)...may struggle to lubricate everything but might not be such a bad idea (just make sure first startup is in a well ventilated area!!!)
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Wow, major surgery!! did you manage to resurrect the silencer(s), if so any pic's ?
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Hi, not a lot you can do really, keep them clean externally, but they rot from the inside out due to condensation and water vapour which is a by product of combustion, you could dry them internally after each ride with a blower, but that’s a bind, look at it this way, how long did the originals last?, probably many years!, will you still own the bike when it becomes a problem?.
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I would suggest using Hydraulic oil.
As it has very low viscosity & it creeps into every nook & cranny.
Sean.
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In the olden days we used to pour 2 stroke oil into new silencers and swirl it around, don't really know if it helped as we did not keep bikes long in those days.
Cheers
Dennis
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The best thing you can do for exhaust internals is avoid short journeys, run for at least half an hour and give it some stick to get them really hot to boil all traces of moisture out of them. Short journeys or just starting it for a few minutes is truly the worst thing possible for bikes full stop.
Sent from my X6pro using Tapatalk
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I've just had a eureka moment !! i have bought in the past a gallon of black Waxoyl, i intended to buy it in clear, used a bit on a car underside but it was to messy, the clear is much better. So to use it up i could thin it down considerably with thinners, the thinners will evaporate leaving a thin film of Waxoyl, what do you think ??
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I cannot believe how much rusty water came out of my USA 2 trumpet exhausts on my 750k. Was blowing out of the joints too
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I've just had a eureka moment !! i have bought in the past a gallon of black Waxoyl, i intended to buy it in clear, used a bit on a car underside but it was to messy, the clear is much better. So to use it up i could thin it down considerably with thinners, the thinners will evaporate leaving a thin film of Waxoyl, what do you think ??
Waxoyl is as the name suggests, wax based. Will probably burn off first time the pipes warm up properly, may even get you a tug from the Police for excessive smoke! Waxoyl is wonderful stuff, and if you were laying the bike up for 6 months or so, fine, but it will burn off very quickly when the pipes heat through. Engine oil and 2 stoke oil etc will also burn off quickly, and again the smoke issues.
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You could place a couple of low wattage garage tube heaters under the exhausts when you leave the bike in the garage, that would evaporate the internal moisture out quickly, but I think the best option is just to forget about it, they’ll probably last 15 years, you’ll be 85 with probably more to worry about than rusty exhausts 🙂
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Every few tanks of fuel I add some 2 Stoke oil whether it helps or not only time will tell.
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You could place a couple of low wattage garage tube heaters under the exhausts when you leave the bike in the garage, that would evaporate the internal moisture out quickly, but I think the best option is just to forget about it, they’ll probably last 15 years, you’ll be 85 with probably more to worry about than rusty exhausts 🙂
That's a sobering thought :'(.
I like the suggestion of the tube heaters, i'll look into it but i will still try the Waxoyl route, the area that rots is the silencer, do they get hot enough to burn away the Waxoyl or just melt it into a liquid state which is ok.
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I have 341's on my k1 I don't look after them as well as I should.
They have been on there for 5 years and there is no rust on them the bike is used in the rain and always long journeys. 50 miles minimum.
In that time I have removed them twice to clean them properly.
What I have noticed is the left lower pipe fills with water if the bike is stored over winter on its side stand.
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I have 341's on my k1 I don't look after them as well as I should.
They have been on there for 5 years and there is no rust on them the bike is used in the rain and always long journeys. 50 miles minimum.
In that time I have removed them twice to clean them properly.
What I have noticed is the left lower pipe fills with water if the bike is stored over winter on its side stand.
Thats odd !! do you think all the pipes would collect water on the main stand ?. Do you know if there is much performance difference over K1 pipes ?
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Iv not noticed much of a performance difference.
The 300's make you feel like your going faster because of the extra noise. Your ears will thank you for the 341's
From memory I think its due to the positioning of the drain holes. If started up after standing awhile the left pipe sometimes spits a little water out of the drain hole I normally only get whiffs of steam from the other pipes.
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You could place a couple of low wattage garage tube heaters under the exhausts when you leave the bike in the garage, that would evaporate the internal moisture out quickly, but I think the best option is just to forget about it, they’ll probably last 15 years, you’ll be 85 with probably more to worry about than rusty exhausts 🙂
That's a sobering thought :'(.
I like the suggestion of the tube heaters, i'll look into it but i will still try the Waxoyl route, the area that rots is the silencer, do they get hot enough to burn away the Waxoyl or just melt it into a liquid state which is ok.
They do get very hot, as does the gas travelling through them, it would almost certainly burn off the internal baffles, and probably run out of the drain holes causing a mess, , if you’re set on using it I’d try it in one silencer first, I think a low constant heat from a couple of tube heaters is your best bet , it would keep the rear of the bike bone dry as well 👍