Quick Fuel float adjustments

93xs2003@gmail.com wrote: No doubt those external barbs work fine for venting crankcase gasses. I'd be interested to know k&n's official position on using them for fuel pump overflow. I don't have a sense of how much fuel could flow when a diaphragm fails, but I'd think you would want raw fuel to be dumped directly down the throttle bores (like a 4160) rather than outside the arrestor. I'm assuming the nn-85-1325 does not penetrate the arrestor/filter. It's a shame QF didn't just put a fuel overflow barb on their marine carb..

Sounds like you need to talk to K&N to see how they justify that it meets USCG standards.

Probably through their own testing and not by Underwriters Lab testing for Coast Guard Approval.

There's a difference between "meets Coast Guard standards" and "USCG approved'

A good example of that is a DUI marine distributor. It meets the standard but it hasn't undergone the UL testing.

The testing is Expensive (with a capital E) and their legal department must be comfortable justifying that it meets the standard through their own testing. (The uscg says if you meet SAE J-1928 or UL-1111 requirements, you're OK)

I could modify a flame arrestor or modify a distributor to meet the standards pretty easily but come testing time, it's a whole lotta money involved.

People on here have modified their flame arrestors and distributors and might also throw in carburetors to become "marine" to them, but that's their choice for personal use. and in the case of older stuff they improved on the original 60's equipment.

No doubt those external barbs work fine for venting crankcase gasses. I'd be interested to know k&n's official position on using them for fuel pump overflow.

I don't have a sense of how much fuel could flow when a diaphragm fails, but I'd think you would want raw fuel to be dumped directly down the throttle bores (like a 4160) rather than outside the arrestor. I'm assuming the nn-85-1325 does not penetrate the arrestor/filter.

It's a shame QF didn't just put a fuel overflow barb on their marine carb..

The page in the link has some "other brand" applications listed and also has a listing of vent hose adapters that you can get separately like the fuel pump overflow fitting etc.

link

Which K&N are you using?

When I installed a QF carb, my original flame arrestor would not clear the float adjustment screws, so I replaced it with a barbron 5-3/4" dia. aluminum arrestor. Float adjustment issue fixed.

I wasn't happy with the cold start idle.   I went down early in advance of the skiers and dialed the choke in while cold.   Shut down, buttoned it up, restarted and pulled away from the dock.   Idle was terrible. Pig-rich, Stalled.   Float bowl sites show normal fuel level.    Restarted & cleared it with a little throttle.   Idle is now perfectly fine. Huh? Does not compute.

What was happening was the 5-3/4" arrestor was interfering with the choke butterfly shaft. Depending on very slight shift in arrestor centrality, arrestor rotation, bolt torque, engine vibration, etc. the choke would intermittently stick until the bi-metallic spring overcame the friction of shaft against the arrestor.   

There was a small witness mark (burnishing of the black coating) on the choke shaft on the end opposite the bell-crank. If you are running a 5-3/4" arrestor, check for interference.

I am in the northeast corner, by Devils Tower, about 4200 feet.

Where did you buy your jets from?

Sounds good, I will keep it plugged.

I will definitely be changing jets at some point, I've been fallowing JQ's posts with the protec swap.

JQ did you change both the primary and secondary jets sizes?

Are you running stock jets? I'm in SLC area and I'm running 2 sizes smaller on jets for the altitude. I typically run between 4,400 and 6,200 feet elevation in Utah. FWIW, She runs like a scolded dog...

JQ

If you hook into the other port right next to the one you're probably hooked into, you should get a vacuum reading at idle.

One is full manifold vacuum and the other that you probably hooked into is the timed spark port that reads above throttle plate vacuum and at idle it'll read about zero.

Hook into the manifold vacuum port and it'll give you the readings you're looking for.

They look like they tap into the same place but they don't.

I'd imagine that you're at a fairly high elevation out there in Wyoming and the idle mixture adjustments make sense.

How high are you? elevation wise that is

Good job, hope it keeps running good now

A picture of the vacuum port with the gauge hooked up might be helpful if you say you have no vacuum reading.

Have you verified the secondaries aren't leaking/dripping at idle.

I see you took off the primary bowl but not the secondary. If you have junk in one you have a good chance of having junk in the other

Never had time to change plugs this week.
The power valve is 6.5, the idle was set at one and a quarter out.
When I set the idle screws I had a vacuum gauge hooked up to the carb vacuum port and I didn't have any reading at all. It is running terrible rich at idle. It loads up and starts fouling plugs until I run it at higher rpm. I was going to try 3/4 turn out on the idle for a while and try that.....

Timing is at 10 deg. BTDC

One thing I've done with marine carbs is to extend the vent tubes a bit. (raise them).
Boats move up and down much more than most vehicles do. It helps.

I took the primary bowl off and found half dozen little tiny metal shards in the bowl. I didn't see anything on the needle and seat. I was hopingI would see something a bit bigger. I guess if it was bigger there would probably be gas dumping out of the overflow. I'm hopefully going to get out this evening and run it again fingers crossed.....

Jonny Quest wrote: Duane in Indy wrote: TRBenj wrote: Believe Holley purchased QF ~5 yrs ago. Last year is what they told me +1 Same story I got from QF / Holley when I called to get recommendations for secondary jets. JQ

JQ I checked with my dentist and he said to do a Google search and you'd probably find that in 2012 (that's what 5 years ago?) QF was bought by the holding company that bought Holley after some bankruptcy problems Holley had. Everything changed hands a couple of times and now there is Holley Performance Products Group that owns quite a few aftermarket companies and QF is one of them

Holley history (a long and winding road) link

Some QFT historyQFT

So High Performance Industries who at the time owned Holley bought them in 2012

Then everybody changed hands again once or twice after that. That's probably part of the story

So in the end I said to myself"who cares when it happened? or how many times it happened. Just one big incestuous aftermarket industry where everybody keeps getting bought and sold by investment groups

Kinda like being married to your cousin or something and then divorced and remarried again

I'm sure this isn't the whole accurate story because it's probably next to impossible to figure out but it sounds like everybody's right ...........sort of