mtn Hawking-Problems using last 1/3 fuel tank

[snow hawk gal]

Not a fella,

but welcome to Team Snow Hawk.

Getting one and experiencing it is addicting, ask Tony!

 

[whistlerhawk]

Walbro fuel pickups are too big for Hawk fuel tank

The walbro fuel pickups are too big to fit into the Hawk tank. They use them in 4x4 fuel cells to solve exactly our problem; however, they are almost 3" in diameter and 2" tall. They would never fit in through the gas cap of the Hawk. The artic cats all have huge gas caps you can fit you arm into so they don't have the problem fitting them. Unfortunatley Walbro does not make any smaller fuel pikups

Back to square one trying to figure out a reservoir tank either between the main fuel tank and the fuel pump or between the fuel pump and the carb. Vapour locking may be an issue ) i.e. air bublbe getting trapped in the reservoir.

Another option perhaps is to make a small rectangular resevoir (1/3 liter) in the main tank attached to the end of the fuel line with a baffled gate allowing gas into the resevoir with gravity and not back out into the main tank...or perhaps a small hole in the front of the resevoir and a small hole at the top allowing fuel to get into the resevoir but wouldn't drain out too fast when tipped back. The hole in the top would allow air to escape or fuel in. This might buy 1 minute of fuel before emptying. This would solve any vapour lock issues and be non mechanical. The Hawk would have to level out to allow gas to flow back into the resevoir...

I have to solve this for this upcoming season...

 

[TLKDPROD]

Inner reservoir + foam

I alos realized Walbro fuel pick-ups were too big this morning when I went to my local AC dealer...

The idea of an inner fuel tank inside the main tank doesn't sound bad at all to me. The opening on our tanks has a little more than 2" and would allow us to slide up to a 2" OD tube in there. This 2" OD tube capped at each end and drilled to create a baffled inner tank with a fitting for the fuel line would probably be good enough. I wouldn't drill it all around, I would probably drill, like 120 degrees around and holes would have to be pointing up and forward so that when we climb, the gas doesn't come out and when we are levelled, the inner tank fills itself back without trapping air into it... just like you said WhistlerHawk. Or have that thing with a baffled gate...

How to hold that round thing down there and oriented right ? I think adding fuel tank foam would be good enough, plus all the advantages of the foam into a tank...

An aluminum 2" OD tube by 1/16" thick (1.875" ID), by, let's say, 11 inches long (tank is close to 13" wide where the fuel line hole is) would hold 19.3 cubic inches of liquid. That's 0.316 liter... Yeah, that may just buy us 1 minute of climbing when we're down to the 1/4 of our 45L tank... but that's still a lot better than 10 seconds !

 

[TLKDPROD]

Just got another idea...

I would suggest we get the opening of the tank bigger and use the Walbro fuel pick ups. We gotta admit it : that's the only permanent solution. Get rid of the neck of the tank by drilling a 3" hole with a hole saw on top of the tank to finally fit in the Walbro pick-ups found at all good'ol local AC dealer. We've got lots of room to do that on top of the tank.

And replace the neck ot the tank/gas-cap with something like that: http://www.lightech.it/default.asp?sezione=damoto&cat1=78 .

Of course that's the fancy thing from Italy but I'm sure we can find something more industrial, same idea, flush mount unit, held by the inside of the tank with rubber (to seal), washers and nuts. And of course sealed with some kind of a rubber washer all around... at a more decent price. Besides... that would look so cool !

Any feeds on a decent priced fuel tank cap like these I pu as a link but "glove-friendly" (!) let me know ! I think we've got a solution here ! Thanks !

 

[snow hawk gal]

Maybe?

http://www.clarkemfg.com/cgi-bin/mi...de=CM&Product_Code=DBCC&Category_Code=GASCAPS

Make the hole larger in the filler area.

http://www.justgastanks.com/store/index.php?main_page=index&cPath=68

 

[TLKDPROD]

Yes !

, that's exactly what we need ! They even sell the back up ring with the gasket! I sent them an email to know about the dimensions.

And I woke up last night thinking about the rear fuel pick up not being able to clear the "simili-baffle" we have in there but seems like it would clear as we've got more than 3" high and a little more then 1.5" at the top where it's the least wide.

Add some foam in there, we're gonna solve the problem i'm damn sure ! Sorry, I'm really sold to this idea as I found slushing in such a big tank was a problem.

 

[Travis616]

What about putting an opening somewhere else in the tank and then it would still look the same from the outside. Bombardier fuel sender style of setup would work, a bottom plate with small studs that push up through from the inside, a rubber gasket, then the top plate bolted down using the small bolts/studs from the bottom plate. A bit of aluminum and some measuring could turn out a factory looking piece.

 

[snow hawk gal]

Verry little clearance for this option.

All 800HO's were wearing through heat exchangers if 12gal fuel tank was used, not much flat surface area to be had, maybe on top under seat.

 

[TLKDPROD]

On top of the tank under the seat would be a potential area fur sure to put another opening. That's a pretty good idea actually because it would allow us to put/reach the pick-ups more easily I think. That being said, my conscience is a little worried about drilling holes in a gas tank... especially in an area that will be in contact with gas all the time like on top unde the seat... and the less holes i'll drill through my tank, the better my conscience will feel ! So I think I'm gonna stick with the idea of making the top hole of the tank larger by retrofitting a Clarke / IMS Dry break conversion gas cap and slide the Walbro pick-ups in by this hole. Then fill the tank with foam to reduce slushing !

 

[whistlerhawk]

I think we're onto something here. Once you find out the dimensions for the hole for the dry-break conversion kit, let us know. It has to be at east 3" to fit in the Walbro fuel pickups. Also find out if there are any issues with it sealing to a plastic tank. I think the top filler hole is the best one to retro fit with the new filler cap since it is high and dry most of the time. I agree that the walbro will be the best solution to this issue. I was thinking one Walbro at the front and one at the back. The fuel line coming into the tank could be split with a 'Y fitting. Then have one fuel line go 4"-6" to a centre mounted walbro near the front of the tank and the other going off of the 'Y' fitting to the back of the tank as far as it will go. The Walbro site suggests that one of the fuel pickups be vented. Looks like a fairly cheap reto fit. Certainly worth the money if it solves the problem.

I have a question about fuel foam. Do you stuff the tank full of the foam cubes or just a few. Does anyone have experience with this in any other tank?

 

[J&L Snowhawk]

just a thought to fuel on

After installing my 12gal. tank I relocated the fuel line fitting to the top of the tank just in front of the choke, can use shut off valve and remove line so tank can be easily completely removed. Now to the fuel starvation problem. If we use a sooper flexible fuel line, Maybe a coiled line like used in chain saws, and run it with a heavy weight on the end so it will travel front to rear when tipped front and back. What are your thoughts

 

[TLKDPROD]

Whistler Hawk,
The guy at justgastanks.com told me outside diameter was 4.25" and that the holes were drilled on a 4.00" diameter. I totally beleive the 4.25 but I dont beleive the 4.00" Diameter Bolt Circle, he must have measured it wrong for sure. If you look at the back-up ring and gasket that you have to buy with the cap to have the hole sealed : ( http://www.justgastanks.com/store/index.php?main_page=product_info&cPath=68_80&products_id=897 ). If the Outside diameter of that is 4.25 I think there's something like 3.25". I was sure enough so I ordered one last week, should get it this week. Will keep you aware when I'll get it.
Top filler will definetely be the best area to retrofit that, I agree and we have enough room to drill a 3" hole no problem and drill a 4.25"-4.5" hole in our plastic.

Relocating the fuel line fitting to the top and add a shut off valve doesn't seem like a bad idea at all J&L.

As for the pick-ups, I would like you to go and have a look at how A-C arrange theirs, sorry I couldn't copy the exact page so you will have to do a bit of work here :
http://arcticcat.arinet.com/Empartw...b&LoginID=cotest&loginpwd=cotest&partner=ARCC
Once you're there, type "Crossfire" then choose any model there, then click and click on the "FUEL PUMP ASSEMBLY" drawing.
Seems like one of the 3 pick-up has 2 connections; one to another pick-up and another one to the fuel pump, I don't know if we should go ahead with something like that, if there's a reason for that OR just go with what you propose, split the hose with a "Y" that connects to 2 pick-ups.

Tank foam : you stuff it. One question I have is I am kind of wondered on the fact that this foam may retain some fuel though... If, for example, there's always 1 liter being trapped into this foam, it wouldn't be awesome. I'll get more info on that as well.

 

[J&L Snowhawk]

600.00$ gas tank

I'm not sure I would just hack a big hole in my tank to try this, sounds like it should work but expensive and risky JMO Anyone have a Idea on where to get soft-flexible 1/4 in fuel line?

 

[TLKDPROD]

Got it !

I just got my dry-break conversion cap I ordered last week and we're gonna be good to go to do the mod with that ! The hole that we have to hole-saw in the tank to make it fit is 3.5" so that leaves us more than enough room to slide the pick-ups in.

Talked to the guys at EVOMX and they said the foam doesn't retain gas at all, the pores are small enough to prevent slushing but still, big enough so that gas can "flow" into it without being retained in.

 

[TLKDPROD]

Problem solved !

Hi everyone,

I just did the modification yesterday. I Installed 2 Walbro pick-ups, one at the front and one at the back. I made custom alu brackets held by underneath with bolts sealed with rubber washers to hold the pick-ups down.

I tested it : I bleeded both fuel pick-up lines so that there's no air in the lines, then tilted my tank back, leaving the front pick-up high and dry, the Hawk idled there on his stand for like 4 minutes no problem, fuel was being picked up by the rear, submerged, pick-up only. Problem solved.

If you ever go through most of your 45L tank and end up with this problem going uphill, I've got the solution to email you, about 35 pictures and some tips for sure to avoid hassles i've gone through to install these up !

Now no more sledders can laugh at me or ask what's happening with this weird machine going uphill really good and suddenly shutting off ! And bottom line, my motor will just be happier not to run out of fuel at 8000 RPM... and i'll be happy to go straight up a hill without releasing the gas !

 

[TKswild1]

Pic's

I am very intrested in seeing the pic's of the process.

TKswildboys@msn.com

Thank's

Tom

 

[TKswild1]

Thank's again

Theirry thank's for the pic's, that look's like some thing I will prolly get done here pretty quick.

Later

Tom

 

[revkiller900]

i mounted a 1 litre coolant bottle off a polaris where the sparebelt holder was on the belt cover ran some fuel line from the tank to the bottle then to the fuel pump drilled a hole for a vent line in the cap and spliced it in with the tank vent seems to work fine but well see if this will work as soon as the snow flies!

 

[J&L Snowhawk]

cheap and simple

I kept my system simple. I just relocated the fuel line inlet to the hight spot on tank behind choke lever then ran blue poly line all the way to end of tank installed fuel pickup screen and a couple large nuts on hose above fuel pickup to add more weight. If gravity does its job should work no problem but will have to wait and see.