Posted May 23, 201410 yr comment_448338 Recently purchased a set of round top SU carburetors twin Hitachi HJG 46W. What can i use as damper oil for these carburetors that have been sent dried? WIll 3 in 1 oil work? or can i use 10w 30 nissan motor oil?Please advise. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/ Share on other sites More sharing options...
May 23, 201410 yr comment_448340 Never thought I'd be one to say this........but, did you bother to type "damper oil" in the search box in the upper right corner of the page? Search is a wondrous tool and opens the door to a wealth of collected knowledge.Dennis Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448340 Share on other sites More sharing options...
May 23, 201410 yr comment_448347 3 in 1 seems to go away too quickly. I like using 10W30 engine oil. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448347 Share on other sites More sharing options...
May 23, 201410 yr comment_448352 I personally use 3-in-1 branded straight 20w motor oil, comes in a convenient little squeeze bottle like the normal 3 in 1 and has a picture of an electric motor on it. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448352 Share on other sites More sharing options...
May 23, 201410 yr comment_448354 3-in-one in the blue and white bottle is what I just used, after searching the archives. The outside temperature matters, from all that I read. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448354 Share on other sites More sharing options...
May 23, 201410 yr comment_448357 The damper is simple and you only need to remember 3 things:1. 30Wt for hot areas, 20Wt for cooler areas (from Mr Matsuo).2. The oil just dampens the piston from bouncing when going over bumps and from engine vibrations.3. The oil regulates how fast the piston rises and falls when transitioning throttle. If the oil is thick, the piston will rise slower and there will be more depression (vacuum/suction) at the bridge and it will pull more fuel from the jet. Think of it as a pseudo- acceleration enrichment circuit. It has the opposite effect on deceleration; with thicker oil it will fall slower and pull less fuel. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448357 Share on other sites More sharing options...
May 23, 201410 yr comment_448366 btw Mr. Matsuo has SU in his name Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448366 Share on other sites More sharing options...
May 23, 201410 yr comment_448393 I have used ATF in my carbs for sooooo long I'm still taking it out of a cardboard can...... These really are the world's crudest shock absorber. I've micced enough of them to say with some assurance that there are two different sizes of pucks......so as you are fiddling for your solution play on...... Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448393 Share on other sites More sharing options...
May 23, 201410 yr comment_448394 I have used ATF in my carbs for sooooo long I'm still taking it out of a cardboard canThat's Commandment #11. :classic: Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448394 Share on other sites More sharing options...
May 27, 201410 yr comment_448601 ATF works horrible for me. I've run 20wt motorcycle oil with best effect. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448601 Share on other sites More sharing options...
May 27, 201410 yr comment_448625 btw Mr. Matsuo has SU in his name [ATTACH=CONFIG]71658[/ATTACH] And a pic of you holding an SU. Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448625 Share on other sites More sharing options...
May 28, 201410 yr Author comment_448692 What about using 3 in one multipurpose oil? Will it work? I dont seem to find 3 in one motor oil here in Panama. Just this one:3-IN-ONE Multi-Purpose Oil | Household Oil | Lubricate Bikes, Guns & More Link to comment https://www.classiczcars.com/forums/topic/49287-damper-oil-for-hitachi-su-twin-carbs/#findComment-448692 Share on other sites More sharing options...
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