1982 nu50 oil injection question.

NOPED I know but I'm working on it for a friend, it's a 1982 honda urban express nu50. I'm wondering what all has to be done to remove oil injection in order run a different carb. There's weird hose spigots everywhere, 3 on the cylinder head, what's up with that? I removed the bolts on the oil pump to check out the injector but now with all bolts removed it still doesn't come off. I'm assuming is connected somewhere inside the case as well. Do I just bolt it back and cap off the spigots on that and the one on the intake (if we end up running the stock intake of course)

Re: 1982 nu50 oil injection question.

PS, original plan was just to hardwire it, but upon removing things I discovered it's in rough shape, carb is trash, probably gonna need a top end rebuild, gunk everywhere from a gnarly exhaust leak. I can handle this, just never dealt with oil injection before and it broke my brain when I looked at it.

Re: 1982 nu50 oil injection question.

The 3 hoses to the head are the auto choke mechanism. Pretty simple if you see a diagram, pretty absurd if you just look at it. The injection pump only has one bolt holding it in, then you need to wiggle and pry it upward to unseat the o-ring. You need to leave the pump in place though because it is a direct hole to the crankcase, it is crank driven. You can either disconnect the lines and leave it (mine has been fine for a long time) or take the output line and loop it back to the input and fill the line with some oil to let it circulate in a loop. If you are replacing the carb with a different model then you likely will be able to get rid of the choke altogether. Some carbs do come with injection inputs though and if you are keeping the cylinder stock I would look for one that does. The injection system is quite good.

Re: 1982 nu50 oil injection question.

If we end up doing the stock keihen route, does anybody have a clear picture/schematic for all the hoses, the ones from the manual are very hard to understand clearly and doesn't show the full route for some hoses

Re: 1982 nu50 oil injection question.

? The service manual seemed quite clear to me.

choke.jpg

Re: 1982 nu50 oil injection question.

Oh sorry, I meant for the oil injection and all, yeah the auto choke seems pretty easy

Re: 1982 nu50 oil injection question.

The oil injection is dead simple. Tank goes to pump, pump goes to carb. Throttle cable goes to oil pump and the tension is set so that the pointer on the actuator lines up with the mark on the pump body when throttle is wide open.

Re: 1982 nu50 oil injection question.

I saw a video of some dude just taking the while assembly off and plugging the hole with and rubber expanding plug, it was on an nc50 though, could I do the same if swapping to non injector friendly carb?

Re: 1982 nu50 oil injection question.

If you trust an expanding plug to not turn brittle and leak, resulting in catastrophic seizure or stranding you somewhere, sure.

Re: 1982 nu50 oil injection question.

Downhill Harvey (OFMC) /

Keep the injection.

Re: 1982 nu50 oil injection question.

7/8 inch expansion plug works, just keep an eye on it, i replace mine every other year or so. or hacksaw the drive gear off the bottom of the pump shaft and replace the pump, but then you have that extra clutter on the case. or someone should buy this and tell us how it works.

Re: 1982 nu50 oil injection question.

and as for removing pump from case, just grab the thing and pull up, (assuming you've removed the frame), it's just jammed in there with an o ring, similar to the linked plug (edited)

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