oil injector pump

[ohiodude2]

I have a 79 intruder & I think the oil injector pump is stuck wide open. It will start ,but smokes so bad you can't see & also puddles oil on the floor out of the exhaust. Anyone know what is wrong?

[Lloyd (ljm)]

should be easy to chech the pump.

 Check where the cable goes on the pump, see where the lever is.

 I would think it wouldn't run if the pump was stuck wide open.


 Lloyd

[mswyka]

It may depend upon what has happened with the sled up to this point.  We have had sleds that were started multiple times and not run for long each time that would build up oil in the exhaust pipe and would need some time to heat up and burn out.

With that said, we have also had a bad oil pump.  They are very reliable, but fairly delicate at the same time.  The barrel of the pump has a very tight tolerance within the pump cylinder and is coated with a thin slippery coating.  If grit gets into the pump, or if the pump is run dry it is very easy to damage the coating.  This damage will result in excess oil entering the engine.  If I get a chance I will post a few photos.

If it is the pump, the only thing that I know to do is swap in a replacement.  If you attempt to disassemble the old pump or a replacement pump, be sure to remove the input shaft before attempting to remove the pump barrel otherwise the worm gear on the input shaft will score the coating of the barrel as it comes out.

[mswyka]

Here is a photo of a bad Intruder pump.  What you can see on the pump barrel are two circumferential score marks at each of the oil injector ports.  So instead of just pumping when the ports aligned with the discharge holes this pump would send a small, but excessive flow of oil into the engine continuously.  If you look into the pump you can see the worm on the input shaft.

[jimvw57]

flooded?

[ohiodude2]

Thanks for the replies. I'll get a manual and tear it down.

[jimvw57]

first one I have seen like that. usually it is the banjos or they used an Invader pump with the 3rd port going to an injector. Intruders don't use the 3rd port as it is for the center seal on the invaders, which Intruders don't have

[ohiodude2]

I talked to a friend & he suggested to disconnect the oil lines going to the engine & route them back to the oil tank. That way the pump does not have to run dry. Then just pre mix the fuel.  Will this work?  If so,Does anyone know the correct fuel –oil mix? I know it just a band aid fix & I'll need to fix it correctly later, but I hoping it will let us ride some this winter. Please give me your thoughts……

[gixxer6]

Check to make sure the pump is adjusted correctly. 

I have an Invader that has a leaky banjo, It'll leak oil into the crankcase while sitting over the summer, then smoke like crazy for the first mile or so.  After that, its good to go. 

[jimvw57]

fuel/oil mix is around 25:1  you can run an INTRUDER without the oil injection.

INVADERS need the oil injection for the center seal to work.

[ohiodude2]

Thanks everyone for your replies. I ran it sitting in my barn/shop on the dolly for at  least fifteen minutes all together. It never did stop smoking and blew out a circle of oil about 2 foot.So I'm fairly sure it's not just leaked in oil. So I guess I'll try the bypass way....Thanks again

[mswyka]

I don't have the exact numbers, but at idle I believe the ratio is about 50:1 and at full throttle somewhere around 100:1.  You can do an end around and probably make it work well enough.  But pumps are fairly easy to come by and when you consider that we are all running these 30+ year old machines you will have to say that the pumps are very reliable.  I would encourage you to take the time to get a pump.  I believe that you will have more satisfaction with the sled in the long run.

[Lloyd (ljm)]

  I would agree with Mark

 Having oil injection is much nicer than using premix.
 There will be lots of those pumps around. If your pump is done. I would get another to replace it.

 Lloyd

[jimvw57]

Probably have  a few pumps laying around somewhere.. I hate doing the gas mix thing. I'd fix the pump.

Maybe the muffler got filled with gas and it is just getting cleaned out(?)

[ohiodude2]

 Thanks everyone for the replies.
I apparently was given some incorrect information by my local snowmobile repair shop .I was told it was a very difficult job to replace the injection pump, he said he may need to pull the engine. Well needless to say, I'm done with him if it as you said fairly easy. I did go ahead & with the bypass on the pump & will pre- mix for now. However, I found a pump on eBay& will bid on it. I also found on eBay an  78 intruder shop manual on a CD. Can someone give me an idea what all is involved in replacing the injection pump? Also I mixed the oil 24-1 and apparently that is way too rich, because it's very sluggish at that mix. Can someone give me their thoughs for a good mix?..............thank you