1979 Kawasaki Invader 440

[DiabeticKripple]

Having issues with a ‘79 Kawasaki Invader 440.

Hasn’t ran in 35 years, but we got it going.

Now the fuel pump isn’t pumping fuel to the carbs. We thought it was the fuel pump so we changed that out, but it’s still not pumping so now we are thinking of pulling the engine and changing crank case seals.

It’s got all new fuel lines, fuel pump, sparks plugs, carbs have been cleaned.

Engine runs fine when we use the primer, just not getting fuel in the fuel lines downstream of the brand new pump. Tried pressuring up the fuel tank to push fuel through and it didn’t really work.

[buckbrush]

Did you try pulling the rope for 30 min. at least? Sorry no much help but on my 79 440 that's how you got it running. :budo:

Seriously though, sounds like you guys are ruling out what it could be, were you able to turn it over when you had a bit of pressure on the fuel tank? taking fuel line off of tank it flows freely?

[gmcmax05]

Check fuel line from inside tank to pump, helped a buddy get his 01 Cat going that had only been sitting for a couple years, wouldn't pull fuel from tank. Found fuel line inside tank had totally turned to mush.

[DiabeticKripple]

Fuel definitely comes out from the tank. We changed the pump and got fuel everywhere lol. We have good flow from tank to pump, just after the pump it doesn’t get fuel.

[possum]

Having issues with a ‘79 Kawasaki Invader 440.

Hasn’t ran in 35 years, but we got it going.

Now the fuel pump isn’t pumping fuel to the carbs. We thought it was the fuel pump so we changed that out, but it’s still not pumping so now we are thinking of pulling the engine and changing crank case seals.

It’s got all new fuel lines, fuel pump, sparks plugs, carbs have been cleaned.

Engine runs fine when we use the primer, just not getting fuel in the fuel lines downstream of the brand new pump. Tried pressuring up the fuel tank to push fuel through and it didn’t really work.


Likely a problem with the float in the carb. Or the needle valve is still gummed up. Did you replace the needle/seat and the float in the carb or just clean them ? Float could be cracked or dried out.
IIRC that machine has 2 Mikuni 34MM carbs ??

[DiabeticKripple]

Likely a problem with the float in the carb. Or the needle valve is still gummed up. Did you replace the needle/seat and the float in the carb or just clean them ? Float could be cracked.
IIRC that machine has 2 Mikuni 34MM carbs ??

Everything in the carb is mint. No issues.

Issue is not getting fuel to the carbs.

It idled good for a bit but when you gave it some RPM it sputtered and died. Then it stopped idling so we changed the fuel pump.

Carbs are 2 36MM mikuni.

[possum]

Ok, I have worked on many sleds like that when I was a young fella. My guess would be , that when you start it it will run good till you give it throttle and it creates a vacum in the fuel line from the tank to the carbs and then the line collapses or partially collapses and starves the engine/fuel pump. Either that or you have a vacum leak letting air into the fuel line (IE) cracked fuel hose between tank and fuel pump. If it was cracked between the fuel pump and engine it should be wet or damp.
I would replace all the old fuel lines......Does that engine have a inline fuel filter ?? If so change it.

[elkhunter11]

If I recall correctly, the fuel pump is run off of a vacuum line to the crankcase. I would check for leaks or obstructions in the vacuum line.

[DiabeticKripple]

Ok, I have worked on many sleds like that when I was a young fella. My guess would be , that when you start it it will run good till you give it throttle and it creates a vacum in the fuel line from the tank to the carbs and then the line collapses or partially collapses and starves the engine/fuel pump. Either that or you have a vacum leak letting air into the fuel line (IE) cracked fuel hose between tank and fuel pump. If it was cracked between the fuel pump and engine it should be wet or damp.
I would replace all the old fuel lines......Does that engine have a inline fuel filter ?? If so change it.

It only starts and runs off the primer now. It used to idle but the old fuel pump stopped pumping so we changed it and it still doesn’t pump.

All fuel lines are new so there isn’t any cracks. Brand new fuel filter as well.

EH11, new vacuum line as well, and everything is sealed and tight.

[Desert Eagle]

It only starts and runs off the primer now. It used to idle but the old fuel pump stopped pumping so we changed it and it still doesn’t pump.

All fuel lines are new so there isn’t any cracks. Brand new fuel filter as well.

EH11, new vacuum line as well, and everything is sealed and tight.

It could be crank seals. If they leak, it wont create vacuum to run the fuel pump. Could also be the fuel line inside the tank. I have saw issues before with them idling okay, but once revved up they can collapse and block off flow.

[possum]

OK, if all lines are good and vacum is good. Take the fuel cap right off and try to start it. You may have a vacum lock.....IE plugged fuel cap vent. Or maybe after replacing all the lines and filter you have an air lock.


One thing I would try but don't know how to explain it to you is ......If you have an air compressor after trying the steps above I would seal up yhe top of the fuel tank and put some compressed air in the tank to pressurize it and see what happens when you start it. I have a specially made cap for that procedure but even if you can seal the tank with your hands and blow in it while someone pulls the rope and operates the primer it will work.


Is the machine inside (heated garage) or outside (cold)

[Drewski Canuck]

Take off the fuel line to the tank from the fuel filter, and plug it off.

Take the fuel line to the carbs from the pump OFF.

Get a plastic pop bottle or something similar and fill it with some mix gas. If you can get a small hole drilled in the lid to push the fuel line in, you will be in business. TRY and get as tight a seal as possible please as this can be dangerous if the gas leaks out of the pop bottle. IT CANNOT LEAK AT ALL.

Next, simply lift the new fuel source over the height of the carbs and tilt the pop bottle to feed the carbs. Does it start? Does it idle?????

Most important, do you get alternating pressure from the VACUM line from the crank case to the Fuel Pump when the engine is running???? If not, replace the line and try again.

These pulse fuel pumps can be a pain. If there is water in the prime side, the pump will not run. The water is now of course ice and the pulse pump is probably ruined. They are not easy to rebuild, and it is cheaper to replace them if your time is worth anything.

If you are not getting the thing to start, run, idle, it is the carbs, and likely a stuck float. Try putting some sea foam in the fuel oil mix and get it in the carbs to soak. Then try and start again.

Good luck and tell us how it goes.

Drewski

[mac1983]

I was having the same issues in an 83 invader. New crank seals and oring seals between cylinders on crank. After 35 years of no use those crank seals are rotten. Pressure tested engine to 5 psi, fixed a few leaks.
It now starts on about 3/4 pull, just like it should. I only did this after exhausting all other options, wish i had done this to start it would have saved lots of pulling. lol Awesome classic sleds it will still do 95 mph

[Iron Brew]

Build yourself a leakdown test kit. Cheap, easy, and lets you know if you are pulling the engine apart unnecessarily.

My issue is always carbs. I'm awful with them.

[Night hawk]

Fire extinguisher handy is strongly recommended !

[Rastus]

I had a 1978 Invader, never had problems with it although it was used for racing. Sold it in 1980 and the biggest thing was I used to crank it up on the bench and I blew the shaft on it. OH WELL that was a lot of years ago.

[DiabeticKripple]

It can’t be the carbs since there isn’t any fuel getting to the carbs. They are spotless as well.

Compression is good in the cylinders, 130psi on both.

Probably will pull the engine this week

[tullfan]

Is the fuel pump hooked up correctly.
Its simple. If you have vacuum to pump and fuel into pump but no fuel coming out of pump then bad fuel pump or incorectly hooked up.
Crank seals maybe, but if it runs with primer then it runs. Crank seals probably good.
Something is missing, or being over looked. This problem should be diaged or fixed in under a half hour. Fuel,air,spark. If it has em it has to run.
Tullfan

[DiabeticKripple]

Vacuum is hooked to the top where it would activate the diaphragm. Then for the fuel lines there is arrows, 1 going in and 2 going out. The 2 going out go to the carbs, one in is from the fuel filter.

[lannie]

Make sure the seal between the carb and the crank case is good. Usually a rubber hose type of thing in between. If there is any vacuum leak between the two you will never get any fuel flowing into the carb without vacuum.

[Joe Black]

you have probably done this already, but if not. If you can keep it running by priming, get it running and disconnect the hoses on the outlet side of the fuel pump. Is gas coming out? If not, yes start tracing back pump then suction in the crank. If crank seals are gone/weak you want to change asap. If not when you do get it running, you will lean out and burn down. $$$$$$$$$


If gas comin Out, then carbs are plugged. Way simpler problem.

[tullfan]

So to recap.
You have fuel from tank through fuel filter and into pump. Verified and visually checked. Correct.
There is vacuum being acted on pump from engine. Verified with gauge or other method, correct?
Then when engine is running or being pulled over there is fuel coming out from 1 or both of the outlets from the pump to the carb/carbs. Verified by pulling 1 line off at pump outlet. Correct,not correct.
If no fuel comes out and you have vacuum then and fuel in, then pump is faulty.
If you have fuel in no vacuum no fuel out, then vacuum line plugged or need to fix no vacuum issue at source, that would be engine.
if you have vacuum in, fuel in and fuel out and won't run, carb issue, although doubt both carbs faulty.
So after all the checks, which component is missing? Vacuum,fuel in, or fuel out?
hope this helps a bit.

Tullfan

[DiabeticKripple]

So to recap.
You have fuel from tank through fuel filter and into pump. Verified and visually checked. Correct.

Correct

There is vacuum being acted on pump from engine. Verified with gauge or other method, correct?

Not verified by gauge, but can put your thumb on it, and can feel it pulsing, although it is a bit faint

Then when engine is running or being pulled over there is fuel coming out from 1 or both of the outlets from the pump to the carb/carbs. Verified by pulling 1 line off at pump outlet. Correct,not correct.

Fuel came out of the pump about 2” into the fuel lines and doesn’t go any further on both fuel lines to the carbs but doesn’t go further

If no fuel comes out and you have vacuum then and fuel in, then pump is faulty.

Brand new pump, should be good

If you have fuel in no vacuum no fuel out, then vacuum line plugged or need to fix no vacuum issue at source, that would be engine.

New vacuum line and it’s sealed good on both ends

if you have vacuum in, fuel in and fuel out and won't run, carb issue, although doubt both carbs faulty.
So after all the checks, which component is missing? Vacuum,fuel in, or fuel out?
hope this helps a bit.

Tullfan

I think the vacuum isn’t strong enough to pulse the diaphragm in the pump.

[mac1983]

If you have access to a running sled that uses a similar pump you could try it out. My sled would run, hard starting for sure, and i had to melt down a piston or 2 before i rebuilt it with 2 new nikasil cylinders, pistons, rings and crank seals. For parts i went to image enterprise in wisconson, if he's still open(online) he knows those sleds inside and out.

[gtr]

Having issues with a ‘79 Kawasaki Invader 440.

Hasn’t ran in 35 years, but we got it going.

Now the fuel pump isn’t pumping fuel to the carbs. We thought it was the fuel pump so we changed that out, but it’s still not pumping so now we are thinking of pulling the engine and changing crank case seals.

It’s got all new fuel lines, fuel pump, sparks plugs, carbs have been cleaned.

Engine runs fine when we use the primer, just not getting fuel in the fuel lines downstream of the brand new pump. Tried pressuring up the fuel tank to push fuel through and it didn’t really work.

After that much time sitting the crank seals will be dried out. The fuel pump is run off the pulse line from the crank case. As all two strokes function, its a compression, suction in the case that runs the fuel pump. Like a push pull action. A leak down would give you a definite answer to the seal leak. If your sure you have the carbs clean that might be a good test to complete. If you can get it to run by dumping gas in the cylinders, that could soften up the seals if you can get it to run long enough. Good luck with the old girl!:)

[tullfan]

Having issues with a ‘79 Kawasaki Invader 440.

Hasn’t ran in 35 years, but we got it going.

Now the fuel pump isn’t pumping fuel to the carbs. We thought it was the fuel pump so we changed that out, but it’s still not pumping so now we are thinking of pulling the engine and changing crank case seals.

It’s got all new fuel lines, fuel pump, sparks plugs, carbs have been cleaned.

Engine runs fine when we use the primer, just not getting fuel in the fuel lines downstream of the brand new pump. Tried pressuring up the fuel tank to push fuel through and it didn’t really work.

The interesting thing is that it runs fine when using primer. One last thing I would do is gravity feed from an aux tank to carbs before I tear apart the engine. See if it runs. If the pump is pumping two inches theoretically it should keep pumping.
After 35 years a rebuild may be in order but would hate to see that happen and still have a no run situation.
Good luck, keep us posted.
Tullfan

[gtr]

Any luck with this yet?

[DiabeticKripple]

Well it’s running!

Turns out the carb floats were upside down :angry3:

Either the GF’s Dad put them in upside down when he was cleaning the carbs, or the previous owner had done that and my GF’s Dad just put them in the same way as they came out assuming it was correct.

[mac1983]

Nice one, that's the last thing you do before installing float bowl, measure the float level. Haha done similar things myself. Any pics? If you plan on running it much get yourself a service manual. If you can't find one online i have one for an 83 440 invader i could get copied at staples.

[gtr]

Well it’s running!

Turns out the carb floats were upside down :angry3:

Either the GF’s Dad put them in upside down when he was cleaning the carbs, or the previous owner had done that and my GF’s Dad just put them in the same way as they came out assuming it was correct.

Right on! Glad its back on the trail. Thanks for the PM.:)

[DiabeticKripple]

Here’s some pics

https://i.imgur.com/wgHtCEJ.jpg
https://i.imgur.com/bHOKG3D.jpg
https://i.imgur.com/VuaJ51O.jpg
https://i.imgur.com/uovp1yX.jpg

[mac1983]

That's darn near mint. All original?

[DiabeticKripple]

That's darn near mint. All original?

Everything except some stuff under the hood that I mentioned we replaced.

[wildbill]

Well it’s running!

Turns out the carb floats were upside down :angry3:

Either the GF’s Dad put them in upside down when he was cleaning the carbs, or the previous owner had done that and my GF’s Dad just put them in the same way as they came out assuming it was correct.

She should run like new now, that things in pretty good shape!

[DiabeticKripple]

I just took it for a rip.

Man that thing is fast. I didn’t see how fast I was going, but probably over 60mph in less than 4 seconds. Held me back the entire way and I had to let off before I ran out of ditch

[Smokinyotes]

As a kid I used to have a 1980 Yamaha SRX 440. The 440 invader was almost as fast and the 80 SRX would push almost 100mph.

[The Spank]

Those pics bring back memories! Haven’t seen one of those in ages. They were a good machine in their day and plenty of jam!!
And those SRX guys were always good at going faster than anyone else could....at the bar!!! But they sure got quiet at the drag strip?! :fighting0074: :sHa_sarcasticlol:

[gtr]

When you get stuck.. they are more than a handful. LOL

[mac1983]

You should be able to get 90 - 100 mph if it's in good shape.

[tullfan]

One of the first statements that the carbs have been cleaned. Lol. If I had a nickel every time I heard that I wouldnt have to work no more. I’m glad you didn’t tear apart the engine first. Good you got it going. Enjoy.
Tullfan

[Sledin]

Speedometer/dreamometer, have any of the speeds stated been verified?
Most times the speedometer is way out.
Fast is still fast, but it's scary to think about going those speeds on an old sled.


Sent from my iPhone using Tapatalk

[FishHunterPro]

I believe I clocked my old invader 440 @ about 75mph , but for the lack of suspension it feels like your doing 100 lol.