Jonathan S - I'm hoping you can post some pics showing your new fuel line and routing. Interesting you would go straight down and then loop it up under the carb. I don't tink I've seen that routing before. Since you have a 10hp it won't require the fuel flow of the greater hp units so you may not spit/sputter with a little fuel still in the tank. I would recommend holding onto the old bowl, fuel line and fittings. I believe the fuel line itself is copper and the fittings are brass with stamped names. There maybe someone out there that would like to have the line and/or fittings or even the bowl clamp mount and shut off for a 100 point restoration. I've usually been able to salvage them by combining parts from 2 or 3 along with a new gasket and screen.
Don T - thanks for the plug on my Hydro knowledge but I'm honestly lacking it when it comes to the internals of a pump. That's why I didn't really post a reply to Richard. I've read thru that pump info in the service manual a few times, and the cleanliness and tolerances, and all the little parts always scared me away. Since the internals hardly ever have an issue I've just always thought it easier and likely less expensive to replace the entire pump with another used one. Glad to see you're willing to take the plunge and tear one apart.
Richard J - I see Don T provided some good pointers on your pump situation and what happens if you tow a hydro. As I mentioned above I can't really speak to the internals of the pump. I did see some comments about it and there are a few guys that frequent here that have been completely thru them and rebuilt them so I know it has been done, and I was hoping they would respond. I also saw your comment about checking the sponsors so I assume you reviewed their web sites. Since I don't think I'm supposed to specifically recommend any one I would suggest you call all 4 listed that sell parts. I think you'll find they also sell used parts and would be quite happy to quote you a price for a "non-ported hydro pump" for your 125. (The ported pumps are for the newer tractors with hydraulic lifts, and they do have more demand). You might even get a quote for one withOUT the release valves if you don't need replacements, since used valves are likely a replacement item more often than the basic pump assembly. You can also post to the Wanted section of the Classifieds on here. You will want a pump with a good trunion, or at least one with enough material left on it that you can re-work it to like new, or maybe you can find one that has already has the trunion reworked. The trunion repair info is in the FAQ if you haven't seen it yet I would review it. And by all means make sure you also get the infamous mounting gasket for the pump. Also, if you haven't changed your hydro rearend fluid it's the ideal time when you replace the pump. You just as well get a couple gallons of HyTran Plus and a new filter, and do the whole job all at once. Please keep us informed of how you proceed to fix this problem. It happens to be one I haven't seen/heard on here before, and I had some concern that with the age of these pumps we may start to see problems never yet seen since they really don't fail internally (unless they are towed usually some distance).