Need help getting my 300 running properly!

[johndeerejamie]

Hi, I have a 77 John Deere 300 with a kohler motor and walbro wd31 carb

Carb was rebuilt, new fuel lines, clean tank etc

It turns over fine has new plugs and is in pretty good shape. I had a mechanic do some stuff to it as it hasn't run in a Long long time. He replaced the crank seals and fiddled with the carb adjustmentS.
At the end of last winter it would start after a bunch of pulls (takes a while to get fuel up the lines) and then would idle too high that the clutch would start to engage...
He claimed the carb was screwed but I rebuilt it myself and thought it was ok...I soaked it for days and cleaned everything really well.

Is it possible these symptoms would indicate Bad crank seals? Carb? Could it even possibly be a wrong clutch?
Any help or input is much appreciated!

[markzrt1]

I have the same year 300. Does it have a primer to ease starting?

Is the throttle cable moving freely? Maybe try lubing up the cables with silicone spray.

High idle can be a symptom of bad crank seals but since you say they were just replaced...

The clutch should not cause any of the troubles you are describing.

[JDT]

There maybe a problem with the fuel check valve if you have to pull and pul' to get fuel up to the carb.

Check valves cost $5 and are a must with this type of carb as there is not a float bowl in them.

Following up on what Mark suggested, if it had a primer at one time and does not now maybe the primer inlet barb is open(sucking air) and that would be just like a bad crank seal.

I would not question the clutch at this time and congarts on your willingness to tackle the carb yourself.

[johndeerejamie]

Thanks for te replies!

I have replaced the check valve as this sled was left for good part of twenty years and the fuel tank was goo.
It's just getting the fuel up to the carb...once it's there it would start no prob. I will install a primer bulb to make this easier..

Where would this original primer barb thing be if I were to have one? All fuel lines and filter are new by the way.
I love this little machine and want to buy some cool NOS stuff for it but until I get it running right I don't want to spend anymore money on it!

I'm going to wait for the new crank seals and put in some work and ill be back on here with updates or question I I have any!
Thanks again!

[HoosierDeereMan]

One other thing that comes to mind is the metering level spring in the Walbro carb. The metal tang of the metering lever that works the diaphragm should be set at .005" to .020" above the carb body. Adjust the needle end of the lever if it's set wrong. If not set correctly it may be causing the carb to pump to much fuel at idle. This might cause the high idle and clutch engagement you are describing.

Troy

[JDT]

There was not a primer on this machine when new but many are found with one added.

If it had an inline squeeze bulb type primer you would have seen that when you replaced the fuel lines.

If it had a dash primer than there would be a very small and short barb on either the intake manifold, intake gasket or on the carb body itself.
This barb is very small and fits a 1/8" to 1/16" hose.

As for your new check valve in the tank.... many of these are junk right out of the package.
They will not seat and allow fuel to run back into the tank when you shut the engine off.
Then you have to pull and pull to get fuel back up to the carb. Hence the primers were added.

And recheck the meteing lever as Troy suggested.

[johndeerejamie]

Ok thanks guys!
Yeah obviously the check valve isn't working all that great! I hate havin to pull a million times, once fuel is there it fires up instantly.

I do recall checkin the metering arm thing... Ill have another look when I get greasy but I do recall it all functioned good until I got a snowmobile mechanic to do a few things including the crank seals...I didn't want to screw with the timing...

He told me once you screw around with the adjustments on the carb too much you can't go back and it's junk...don't know if this is true. He told me I could just put a newer carb on and it would be fine..

I'm no expert but I felt like I knew more than him!

I kind of regret not just leaving it when it seemed to be running right but I read somewhere your stupid to not change those seals if the sled has been sitting for a long time so I figured I'd do it.

Anyways ill most likely tear it apart this week and be ready for when the parts come, thanks again can't wait to get this thing out on the snow!

[JDT]

Sounds to me like your mechanic had a carb collecting dust on the shelf and he wanted to sell it.

When I hear a statement like that I would question his seal change out too.

[johndeerejamie]

Finally got a little work started...
Changed te clutch side crank seal, it appears the "mechanic" installed the plate which seal goes into upside down. If you guys are really familiar with these kohlers... the plate has basically a 3" (roughly) circle about 1/4" deep tht basically goes into the side of the motor at the crank...and the seal goes inside it..hard to explain obviously, so he had this upside down. Anyways Installed the seal, also one of the four bolts were snapped off...I hope it's ok with just three.

Installed the primer which I'm really happy with. The motor started and did basically the same thing, started idling real high to the point te clutch slides in quite a bit..I didn't have the belt on during this.

At one point seemed to run ok but if you touch throttle it died as has nothing and then eventually just idles down and dies and you can't do anything to save it from quitting.

I did also notice it appears the cylinder head cover seems to be leaking a little where the gasket is...may just need to be tourqued? Not sure if this would be an issue as far as my symtoms..the motor does seem to have power when it revs up but is Inconsistant and dies. I haven't tackled the recoil side crank seal yet...

Any ideas? I really appreciate anyone who took the time to read this even, could metering arm in carb still be a candadite for these issues?

[markzrt1]

Do you have the airbox on when you have it running? Was the seal that you replaced in good shape?

Here is a link to the manual that has some carb settings: http://www.vintagesnow.com/John_Deere_f ... 400_OM.pdf

Do you have a tach on it? I just installed a NOS tach on my 300. It's nice to see what RPM it's at.

[JDT]

Pull your head and check condition of the gasket.

It may be just loose but if you know it is leaking you need to look at it before you just retourque it.

[johndeerejamie]

I always put air breather, snorkel whatever you want to call it when I attempt to diagnose it.

I have fiddled with the carb settings as well as the fuel metering arm in the carb. I tried to adjust it to what the repair manual says....didn't seem to make much of a difference

It starts, usually begins to take off and slowly comes down, sometimes will idle for a bit but then if I use the throttle it just has nothing there unless i feather it carefully and it will rev up and slowly come back Down...eventually it idles Down and dies!

Wierd but extremely frustrating!

Also I do not have a tach Installed...something I would consider buying but don't want to spend any more money until I verify this sled will work!
Thanks for the help!

[HoosierDeereMan]

I had the exact same problem with my 73 400 (340cc). It had a Walbro WDA-32 carburetor. My best guess at what was happening was the fuel metering lever was pumping too much fuel at idle. It would slowly flood itself. When this happened the idle would start to drop off. When you cracked the throttle to rev it back up it would fall on it's face. After pumping the throttle 7 or 8 times it would rev up and catch itself. I tried a Winderosa rebuild kit. Carb was spotless inside. I had adjusted the metering lever several times to reduce how much fuel it pumped at idle. I even pulled the engine down and resealed the crankcase. New seals, 3 bond sealant, and new gaskets did not make any difference. By chance I had a VM 32 Mikuni. I tried it with a 40 pilot jet. It acted just like the Walbro did. So I started dropping pilot jets until at a 25 it would idle and be responsive when you cracked the throttle. My 400 now idles and is very peppy. It runs great to around 6,500 RPM. It starts to fall off and 50 mph is all you get. 1/4 of the throttle is left and slide is fully raised in the carb bore. Plugs read brown at WOT when I kill the engine and check them. I'm thinking the VM 32 is too small for top end speed. I have a VM 34 soaking as we speak to try.

Troy

[Steven Rempel]

< i was having very close to the same symptoms and turned out to be timing issues, I made one of those timing lights from a 6v flashlight and bought a spark plug adapter to measure for TDC with a dial indicator , after setting the timing i went to test for spark with my inline spark tester it fired right up and runs great now, it turned out that the spark was set to close to TDC for my sled, if i remember right i set it to 2mm BTDC hope this helps if not food for thought