'53 Super Fastwin......it wants to run. It really does! EDIT: IT'S ALIVE

I haven't posted in ages, but some of you may recall my many posts last fall & earlier this spring about my ground>>>up restoration of a '53 15HP Super Fastwin.

This might get long....I'll try not to ramble

It's "done", so today I went to the store and bought a tank & a hose. Mounted the engine in the doorframe of the garage, mixed up some fuel, hooked everything up and.....



...problems.

First of all, the fuel line that I got seems to have a defective connector on 1 end: it leaks like a sieve at the engine connector when I pump the primer ball. Reversing the hose moves the leak to the tank. So that's problem #1, but that's easily solved.

So....by holding the connector tightly in place, and with a rag wrapped around it, I could pump the ball enough to send fuel up the fuel lines, through my retro-fitted fuel pump, out of the pump and into the carb enough to "fill the carb" so that a pull of the rope yielded "LIFE"!!!!

Yes...it ran! For about 5 seconds.

So I've got spark, compression, air.....but it would appear that I don't have sustainable fuel flow.

After 2 hours of messing with it, and with the nuisance leak from the fuel connector, I abandoned today's efforts to make it run. Since then, I've been playing it over & over & over in my head, and I can only come to the following ideas:

> I don't believe the fuel pump is pumping.

> I messed up my fuel pump retrofit.

> This fuel pump is wrong (too big) for my 15HP engine & requires operative pressures found only on larger HP engines.

So: here's my pump (which was recommended to me), and how I plumbed it in. It's pretty big, all things considered, and there's so little room under the cowling that this was about as good as I could plumb everything in. The connections are all hose, but the runs are steel brake line. If this is no good, let me know.....



Here's the deal, though, and I just can't shake it: what's so "wrong" with a 2-hose fuel system in the first place? I have a really good mind to rip all this stuff off and go back to a 2-hose system. Tanks, hoses & fittings can be found on eBay, and I'm betting that......configured accordingly....this old engine would fire right up.

That's my story & I'm sticking to it.

Where's my problem? What am I missing?

mn

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

id start with by-passing the fuel connector, and connect the line directly to the pump. ive done a few conversions and have found that any time the pump can suck air instead of fuel, its a problem.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

id then get rid of those spark plugs and go with the champions.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

I'll try that.

Overall, does my pump installation & plumbing pass muster? Is there anything glaringly wrong?

Plugs: if they were at all part of the problem, I'd be getting un-burned fuel out of the exhaust....

....but I'm not. And I pulled a plug: dry.

They may not be the #1 choice, but I've eliminated them as part of the problem.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

all looks good at a glance. ive used 3/16 copper tubing for the long runs, without issue. ( the id of the tubing is the same or larger than the id of the nipple on the carb). just curious tho, why didnt you go with the much cheaper b&s style pump on the 53?....most are rated at 14L/hr).

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

In one of my very first threads (last year), I asked about what pump to use. Several people suggested 438555 (Sierra # 18-7353).

I was taken aback by it's rather-large size, but I used it anyway....althewhile thinking "really?"

If there's a different, smaller pump, I'm all ears. But, as stated earlier, I'm inclined to s-can it all & revert to a 2-hose delivery system. I really can't come up with a reason not to "stay simple".

That said, the issue at hand is fuel delivery.,......no doubt in my mind.

Check me here: I was told that A = Fuel "in", B = fuel "out" & C = operational pulse from the manifold.

Is that right?

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

heres a quote from hightrim when i was inquiring about a conversion with a b&s pump, thats not marked. but your "in line" is obvious as A, ....B, and C do look right to me..but??

"Do the suck/blow test before installing. You should be able to blow, but not suck for the IN nipple. Suck but not blow for the OUT nipple. Suck and blow for the pulse."

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

I would like to hear more about your conversion as I have the exact same engine. My thread (Found here) So far I've on been able to keep it running by gravity feeding it. The gas tank leveled.... well it didn't work well until I used the primer bulb as a pump. I thought it was the filter below the carb. boy was I wrong.

The pump on the 15 is a Mikuni Fuel Pump

it was hooked to the pressure line mod which was doing OK when inside the line was dry but when it got wet inside, it didnt put out enough. Then I decided to moved its suck/blow pulse to the top bypass cover (I see yours is lower bypass cover?) and capped off the nipple near the carburetor. So far it didn't help one bit.

I bet i'll have to buy a new pump to handle the load. So i'll be watching this thread

That fuel line looks aftermarket in the first picture as I always had bad experience with them letting in air.
Probable just as good if you change the O-rings. I ended up returning it and got the OEM one from BRP. It only costed 20 $ more at 60 compared to 40 for aftermarket.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

Another thought, you need the water level in your barrel a lot higher, at least 2-3 inches above the water pump. I have also been thinking about a conversion on a 7.5 project. The plus side is that I can use a single line tank, easy and cheap to come by. On the other hand, the duel line set up worked for a lot of years and did a good job. You can get repair parts for the tanks and make them as good as new. I still haven't made up my mind.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

You need a bigger barrel and a lot higher water level to make the water pump work.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

Or lower your motor mount.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

boobie said:

You need a bigger barrel and a lot higher water level to make the water pump work.

Click to expand...

Daviet said:

Another thought, you need the water level in your barrel a lot higher, at least 2-3 inches above the water pump. I have also been thinking about a conversion on a 7.5 project. The plus side is that I can use a single line tank, easy and cheap to come by. On the other hand, the duel line set up worked for a lot of years and did a good job. You can get repair parts for the tanks and make them as good as new. I still haven't made up my mind.

Click to expand...

Daviet said:

Or lower your motor mount.

Click to expand...

Umm fuel pump not water pump unless it is related in a weird way

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

there is a realationship between the depth of the motor in the water and it running ok, but jmo, i dont think thats your problem. but plz do lower the motor in the barrel , otherwise, when it does run, and it will, you may run it hot.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

If you gravity feed the fuel to the carb, elevate the tank above the engine and run the fuel line directly to the carb, and the engine starts and runs properly then you know the pump/plumbing is your problem. At least you will know for sure where your problem is.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

there's an optical illusion in the top pic, and I can't explain why it looks the way it does, but the water line is above the impeller level by about 2 inches. But, yeah.....it could be deeper in the water, no doubt.

I can't shake the notion: no matter what the issue with the pump / lines might be, just chuck it all, go 2-hose & be done with it. It worked that way for 30+ years (as did millions of other engines). Why am I trying to "fix" that which was never broken to begin with?

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

Nothing wrong with the old duel hose set up.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

just another thought, how soft is the line you are using for the pulse? it may be collapsing under vacuum.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

Daviet said:

Nothing wrong with the old duel hose set up.

Click to expand...

Agree X2

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

nwcove said:

just another thought, how soft is the line you are using for the pulse? it may be collapsing under vacuum.

Click to expand...

I thought about that, too.

I went to the NAPA store & bought "vacuum hose" (no further spec than that).....but still: it *is* vacuum hose.

That said, I've made a decision: I'm reverting to 2-hose. Not to say I'm giving up, but at this rate I don't know if I have engine issues, carb issues, pump issues, etc. I know it's a fuel issue, but where?

So as to reduce variables, all of my pump plumbing is being removed, I got some dual hose (alcohol rated), and I found a tank & connector for cheap on craigslist.

Maybe I'm overly optimistic, but I have this feeling that....once "restored" to original spec....it will fire up on the 2nd pull.

I'll report back in a week or 2 after I get it all re-plumbed.

Re: '53 Super Fastwin......it wants to run. It really does!

Re: '53 Super Fastwin......it wants to run. It really does!

Before you go and change everything, I would try Daviet's idea of connecting the fuel line directly to the carb and raising the gas tank above the motor (put it on a ladder or something) and let it gravity feed to the carb. You said that it runs but dies in about 5 seconds. I know with my 1976 15Hp motor that if I fill the carb with fuel and start it up, I can disconnect the tank hose and it will run for at least 30 seconds. I know there might be a little fuel in my motor's line but I still think a carb full of fuel should give you more then 5 seconds.

In any event, if it runs with the gravity feed, then as Daviet said, you definitely will know that it is a fuel pumping problem. If it doesn't, you are going to be doing all the retrofit work again for nothing.

The other thing you could try (if you haven't) is to manual keep squeezing the primer bulb while it is running. If your problem is just the pumping of fuel, this action should allow it to run. If it still doesn't run, then perhaps your problem is not fuel pumping, and if you can keep it running by manually pumping the bulb, then perhaps it is. All this will at least give you more definitive information. It seems to me that currently you are making your decision, based more on a hunch then on real information.