Im new to the pilots

Im asking about the mixture for my 89 fl400.

One the frame/chassis it tells me 20:1 and online people tell me online its 32:1. People have said the 20:1 ratio. was when oils were not that good so they ran more rich.

I don't want to melt it down by running it too lean and popping the Engine.

All advice is welcomed

Thanks

Jas

32:1
Your comment on the "oils back then not that good" is correct.
Today's oils are a completely different animal.
I own 3 FL350's that I have water cooled heads and cylinders and I run those at 50/1 castrol two stroke oil.

The only way you are going to melt down a piston is if your fuel flow is bad.
You MUST do a fuel flow test on your pump. You need 4.5oz in 10 seconds flow.
You need a stop watch and a measuring container.
Make sure your machine idles as slow as possible without stalling.
Shut it down and then remove the fuel line at the fuel pump.
Put on another hose and run it to the measuring container.
Start your machine and as soon as you see fuel coming to the container start the stop watch.

Note: You are NOT likely to melt a piston if you are a jet size to lean. That's BS.
CO

ok thank you for that.

I did watch all your youtube videos last night on the Polaris and stock pumps. Will try it and post the results.

Thanks again Canadian Oddy

Hello, so I pulled off the pipe to the three way valve and put it into a plastic bottle. Ran Engine and fuel immediately started to flow.
Repeated this three times and all roughly came out 105ml which tells me from the online calculator that it is around 3.55 US floz under the recommended amount.

The manual says check vacumn line I have done that it looks fine.

I have cleaned the filter and flushed the tank.

Whats the next step please.

3.5 oz is a bit low for my liking but you could get away with it if you don't run full throttle for and extended run or load up the Engine climbing a long steep hill.

Next step:
You get a new piece of hose long enough to throw in the tank or gas can and hook the other end up to the inlet of the fuel pump. Re-do the test.
What we are doing here is eliminating potential rusty fuel lines in the tank and the fuel filter which may be plugged or restricted.

NOTE: I don't like what you did by removing the line at the "3 way T". These little nipples on those plastic 3 ways are very brittle now after all these years and will snap off REAL EASY. When you put this back together you better be careful. No shaky hands because you drunk. No fog brain because you got no sleep.
That's why I recommended a new line from the fuel pump to the measuring container.
CO

Ok will try this tonight.

I did think this may damage the 3 way but took the risk.

Message soon.

I run 40:1 avgas and motul 710

So I have put a direct feed from the fuel tank to the pump inlet and a tube from the pump to a collector jug. The results were very similar to the test via the fuel filter, petcock assembly etc.
It did increase but only by roughly 10ml. The vacuum pipe on my Engine is not of the same type as the fuel pick up and feed to the three way valve. It has a cloth finish outside.

Is this the correctly fitted pipe for the vacuum ?

Those hoses are all original.
CO

I don't know which one of the fuel pump videos of mine that you watched (I think I posted about 5 of them) but in the one video I mentioned that I Yamabond the pump and then they passed the test.
What I have found on all of mine that failed the flow tests was that the pulse/vacuum diaphragm develops a small leak. If you silicone or Yamabond the surfaces they seal and work.
You could try that before you buy a new pump.
CO

I think have watched all the fuel pump videos.

I will try to run the fuel mix ratio up some more when I am sure the fuel delivery is correct.

Id rather buy a new fuel pump than do a short term repair.

Is the Polaris predator the fuel pump to buy ? I am trying to do some research and there seems to be quite a lot of unbranded ones out there. but the originals have the makers mark cast into them "TAIYOGIKEN" is this the best to source or can you advise which is best.

1) Fuel mix: Your machine is going to run like crap. More oil will do nothing but load up the Engine. You won't save an Engine with more oil. I actually run my oddy's at 50/1 and when I took an Engine apart there was still oil everywhere inside. There is a thread on it.
2) "TAIYOGIKEN" pumps: Those are Chinese. I have a half dozen of those at least. They work but also develop a leak on the diaphram after some time and then fuel flow drops. As soon as you silicone them they work great and that in not a "temporary" fix. It works. I wish I would have figured that out years ago and I would have saved a bundle.

You are going to find out that the pumps on amazon or ebay are chinese.
If you go to Polaris and get a pump from Japan it's gona cost big. I remember the last one I bought here years ago was almost $100 can dollars.
The difference between the Chinese and Japanese pumps is the diaphram. I did a thread on that. I think one was a rubber type and the other was plastic.
CO

Have you posted and videos on stripping down the pump and re silicone sealing it.

I'm not sure.
Many times I post a vid in youtube and then leave it a short time and delete.
I'll look in my videos and see if I got one and will re-post it.
Not sure.
It's pretty basic. Take the pump apart and then Yamabond the edges of the diaphram and put it all back together.
CO

Just an update on one of the comments I made above.
I just watch several of my pump repair videos. In that one video you can see that the "TAIYOGIKEN" pumps were Japanese pumps.
So in the comment in this thread above where I said they were Chinese, that was wrong.

If you watch the two videos -- "Stock pump test" and "Repaired fuel pumps and flow testing" they give the best info I got.
CO

Edit again: Here is some info I have in my oddy files:
Mikuni pump flow is:
1054 oz per hour 17.5 oz per min
486 oz in oddy tank (3.8 gals, includes reserve)
1 us gal = 128 oz

This means that at that flow you would empty the tank in 28 minutes.
Obviously we get more ride time than that so the pump puts out a lot more flow than what we actually use. The deadly question is "how much flow do we need at full throttle ?".
CO

Edit: If you think you can add mix to your fuel and that will save an Engine you are mistaken. More oil will NOT save your Engine in a lean out. You will melt a piston on the exhaust side. Some may not believe that but I stand by my comment. I have a box fuel of pistons as proof. There are threads here somewhere on those.
The next question is: How little fuel flow can I get away with on a fuel pump ?
I don't know the answer on that so I just stick with the Honda recommendation.
I'm certain you can get away with slightly less because at 4.5 oz in 10 sec flow you would empty your fuel tank in no time and we all know an oddy gets 10 mpg when you are on the pipe (actual mileage the way I have my machines jetted) and 17 mpg if you stay off the pipe. I know this for fact.
CO