Jump to content

Recommended Posts

As has been mentioned, a fuel flow check verifies that the filter is not clogged. Does this fuel flow check then constitute an inspection given that it will achieve the intended purpose?.

Share this post


Link to post
Share on other sites
2 hours ago, Tom Baker said:

I don't think bore scoping the pistons is on the checklist. I have never found any significant metal on a magnetic plug, should I based on that not check the magnetic plug at the recommended interval? I have not found any metal in a Rotax oil filter, should I stop cutting them open? The checklist provides a minimum of what should be check, and in my opinion the inspection intervals on the checklist should be followed.

I think you missed my point:  Just because it’s on a checklist or in a maintenance document doesn’t mean it’s a good idea, or that the specified interval is ideal.

Share this post


Link to post
Share on other sites
13 minutes ago, ct9000 said:

As has been mentioned, a fuel flow check verifies that the filter is not clogged. Does this fuel flow check then constitute an inspection given that it will achieve the intended purpose?.

That doesn’t give a good idea of the trend of sediment accumulation.  You could have acceptable flow and the filter could be 0.1% clogged and no issue or 90% clogged and a couple of paint flakes away from an engine stoppage.  With that method you are inferring condition and not actually verifying condition.

Share this post


Link to post
Share on other sites
2 minutes ago, FlyingMonkey said:

That doesn’t give a good idea of the trend of sediment accumulation.  You could have acceptable flow and the filter could be 0.1% clogged and no issue or 90% clogged and a couple of paint flakes away from an engine stoppage.  With that method you are inferring condition and not actually verifying condition.

I kinda knew that my post would raise some comment.

As far as the trend of accumulation the fuel flow test is a very good guide. I regularly do a flow test and at each service I actually write it down. I would know as soon as there was a

partial blockage of any sort. Whilst I could not see a 0.1% change, I would see any significant change very easily and certainly a long time before a problem is likely.

Bear in mind that the gravity feed is close to 1 l/min. this is triple what your engine needs. I am with Roger on this as I pull the filter at 200 and never find anything, also my flow test has never shown any restriction at all. 

Share this post


Link to post
Share on other sites
26 minutes ago, FlyingMonkey said:

I think you missed my point:  Just because it’s on a checklist or in a maintenance document doesn’t mean it’s a good idea, or that the specified interval is ideal.

I understand your point. My point is that someone way above our pay grade put on the checklist, and I don't think our small sample size is enought to change the recomended inspection intervals. 

Share this post


Link to post
Share on other sites
9 hours ago, Tom Baker said:

I understand your point. My point is that someone way above our pay grade put on the checklist, and I don't think our small sample size is enought to change the recomended inspection intervals. 

Well, there's a balance.  It's true that factory personnel have access to more data, or at least different data than we do.  But it's also true that just because they are from the factory doesn't mean they have all the answers.  Sometimes engineers just make guesses based on the info they have, and then if it doesn't ever come up again if there is not a problem.

The fuel filter inspection interval is something that appears from owner experiences to justify revisiting and review 

Share this post


Link to post
Share on other sites

I’m going to play “devil’s advocate” here. If I know that my fuel flow has been consistent over the past three years (and the filter has been checked during that time, can I make any assumptions about the condition of the filter? It would seem that I could.

I will check it anyway, but I would not expect to find anything of consequence.

Share this post


Link to post
Share on other sites

I never expect to find anything of consequence, but I check them anyway. I am always surprised if I do find something. Only once did I find one almost 50% covered up. It looked like bug carcasses to me.

Share this post


Link to post
Share on other sites
2 hours ago, SportFlyer1 said:

Guys we've gone on for 4 pages about a fuel filter, my eyes are starting to cross.

Suggest you skip rest of thread and give eyes a good rest.

Eyes are good here . . . keep it coming. It's all good information.

Share this post


Link to post
Share on other sites

It'll never make 20 pages. Andy didn't start it. :giggle-3307:

Good thing this wasn't about spark plug color again. :bad_day-3329::clap-3332:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×