Honda-SOHC

Other Stuff => What is it? => Topic started by: scutter on August 30, 2025, 10:53:32 AM

Title: Think it's an oil jet
Post by: scutter on August 30, 2025, 10:53:32 AM

Hi,

Whilst stripping the engine for rebuild/painting, thids appeared on the shed floor!!   Any ideas where it's come from, looks like an oil jet.

Thanks in advance.

Dan.

Title: Re: Think it's an oil jet
Post by: Nurse Julie on August 30, 2025, 11:19:53 AM

Yes, that's an oil jet.

Title: Re: Think it's an oil jet
Post by: scutter on August 30, 2025, 11:24:18 AM

Thanks, where exactly can I refit it?

Dan

Title: Re: Think it's an oil jet
Post by: DomP on August 30, 2025, 11:55:16 AM

May depend on model but on 550s they are between the cylinder head and lower cases.  Make sure you replace it the right way up!

Title: Re: Think it's an oil jet
Post by: K2-K6 on August 30, 2025, 12:24:38 PM

It may be fine detail, but relevant none the less, they are often called "jets" but are in function an oil "restricting" device.

The crankshaft, mains, big ends etc .... all exposed to full delivery/pressure from the oil pump directly .... this to effectively lubricate at designed for attribute.

The restricting "jets" drop that distribution characteristic to supply camshaft at lower rate as the high pressure etc is not needed.

Leaving them out will give excessive supply to top end of engine BUT then starve the crankshaft of its intended rate in supply. Very important, in other words  ;D

Title: Re: Think it's an oil jet
Post by: Bryanj on August 30, 2025, 02:46:27 PM

Yes one each side at base gasket, also act as locating dowel and only goes one way up

Title: Re: Think it's an oil jet
Post by: Oddjob on August 30, 2025, 03:00:57 PM

Make sure it’s not blocked before fitting. Hold it up to the light and look down it.