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Discussion Starter · #1 ·
I bought a 318, 1985 with B43G, with about 426 hours on it this spring. It is in pretty good shape rust-wise.

Amongst the basic maintenance procedures, I did pull the fuel tank and clean it out. I replaced all fuel lines with new filters.

I now have about 456 hours on the machine so I have put on what 30 hours or so since March with no problems.

It has always seemed to run to rich for me, black soot around the muffler exhaust on the side panel and I smell like exhaust after 3 hours of mowing. Really, no smoke to see but obviously it is there.

I have to add about a quart of oil every 6-8 hours of mowing.

Well yesterday, I pulled the 318 out of the shed and started my mowing ritual. It runs for about 5 minutes while I am mowing at full throttle. No missing out, no surging, just pure power.

At about 5 minutes it dies. After about three attempts to restart, it does start and runs for about 20-30 seconds at idle and then dies.

Once it starts and the throttle is moved to full, it immediately chokes out.

I removed the air filter, etc, and notice that when it is idling I do not see any fuel coming out of the top jet and it runs best when choked. However when I move the throttle to full I notice a few drops of fuel coming out the top jet.

So I removed the top half of the crab and soaked it, the fuel bowl was all but empty when I took the top half off. I blew carb cleaner all over the top, etc and then blew with compressed air.

As I have never actually taken apart a carb, I am a little hesitant in going any further.

I bought a valve gasket kit a while back with the intentions of adjusting the valves, hoping that would help with some of the burning oil. Therefore, it looks to me that I cannot get the muffler off without pulling off the front pulley.

It looks like the muffler housing is bolted behind that front pulley, is that the PTO?

Anyways two questions, how hard is it to strip more stuff down to be able to get the valve covers. I've adjusted valves on Briggs with no problems, but geez, they are a lot easier to get to on the briggs I've worked on.

Second question, I've been reading on here about sea foam. I was thinking rather than stripping the carb down any further, after I adjust the valves and get everything back together, I was wondering if you guys think the sea foam might clean out my carb.

The fuel bowl was basically empty, but also very clean looking, no varnish, the throat of the carb looks brand new.

Or am I on the wrong track and there be an issue with something else that is causing the motor to die?

I just don't get how I mowed 4 days ago with absolutely no problems and then it 96 hours later I am here?
 

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Discussion Starter · #2 ·
Also I might mention that I forgot possibly a big piece of information. My fuel filter is a clear bulb type facing the correct direction and only the paper element is saturated with gasoline.

Should the filter be more full of fuel?

I don't recall before seeing a full filter of fuel when I am checking the oil and air filter. 25 hours ago I cleaned the fuel tank inside and out and replaced the fuel lines.

Also in case this makes a difference, I don't believe the fuel cap is the original as the float stem is only 6" long. So I can have 1/2 of a tank of fuel and the cap registers as empty since the float is at the bottom of the stem.
 

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Discussion Starter · #4 ·
Well, I went ahead and took the PTO off and got the carb and manifold off so now I am getting ready to adjust the valves, it can't hurt, I will also check the points again, although I adjusted those back in March when I picked up the 318.

How would I know if the fuel pump is weak?

Also I remember reading on here that someone said to blow the vacuum tube from the pump to the motor once per season, I would think that would be O.K. as I just replaced that (fuel/air) line in March along with the rest of the fuel lines.
 

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Discussion Starter · #5 ·
O.K. valve adjustment question. I am looking at the picture in the TM for the engine on page 15-14. At the bottom it shows the feeler gauge going between the small nut and the metal thing closest to the spring. No matter how I adjust it I can't get a space there as it shows to adjust in the picture. It seems like the space should be measured between the small nut and the larger one.

What am I doing wrong? In a holding pattern right now waiting on some advice.

Thanks,

Scott
 

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Scott,

You must have the cylinder at the top dead center of the stroke on the ignition stroke to adjust the valves, otherwise the valves is being partially opened or not yet closed...

My CTM2 shows this on the next to last panel on page 15-15, but yours might be a new or older issue... You must measure between the valve stem and the smaller nut of the adjustment on the cam follower/tappet as shown here (not between the two hex flatted parts...)


Hope this helps...

Chuck
 

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Discussion Starter · #7 ·
Yes that does help. I just don't have the "feel" when sticking the feeler gauge in the gap like on some other engines. This is my first Onan. . .

Any opinions on my original fuel issue?
 

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I think your float level is too low.
that is why the bowl was nearly empty and the filter isn't full. when the needle is closed the back pressure over rides the pump pressure and no fuel is pumped.

You can test the pump by disconnecting it at the carb and holding the line off to the side. It should pump plenty of gas then. If not check the lines running back through the tractor to the fuel switch and on into the tank. disconnect both ends of each section and blow air through the lines. Don't blow it through the tank you could blow the pick up end apart.

Still my guess is low float level. I had this problem with my 420 after I did the carb
 

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Discussion Starter · #10 ·
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Hello Chuck, You are correct, I was slightly off top dead center and there was pressure on the valves hence the reason I could not get the feeler in there, after some self-educating by multiple turns of the front shaft by hand, I figured out exhaust stroke, combustion, etc. and found true TDC. No sweat in adjusting the valves then. One intake was + .003 and the other was + .002.

Is that enough to let oil slip in to the combustion on cycle and allow the moderate oil burn?

I have it back together and am going to install the starter relay to get the sucker turning over again.

Then I can trouble shoot the lack of fuel issue.

I have cleaned the carb out and blown everything will cleaner and low pressure air. So we shall see. . .

Thanks for your advice so far. I thought maybe more people would chime in but then I re-read my first post and it looks like a train wreck with all the information.

I can see why people are hesitant to post! All good though, some advice from you, John and Dave is better than none!
 

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My first focus would be on the fuel pump. Disconnect the fuel supply hose from the fuel pump, gas should flow out. If you have gas to the pump, then you have a problem between there and the carb and the first thing I would be looking at is the pump or the pump signal hose.
 

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318 W/ 48" deck, hyd tiller, 49 snowblower, 519 cart. Traded in
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Hi, Guy's I'm working 345 with a FD590V-BS04 engine in it. Short block from John Deere is 2742.00$. The locked up and will not turn over. Has any one put a Briggs or Honda in one. That's a lot of money for a short block. Or has any one put in a FD590v-BS05 in there are not JD only Any ideas what to do The tractor and deck and MC519 are in good shape ???
Thank You
Rod in MN
 

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last time I had a locked up motor was because fuel filled the crank case. Hopefully you checked that first.
 

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318 W/ 48" deck, hyd tiller, 49 snowblower, 519 cart. Traded in
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HI I did drain the oil it was very low no fuel in oil Removed spark plugs there were dry Removed the elec clutch when taking out clutch bolt the engine would not turn with plugs out What is the deferent in the Kawasaki FD590v-BS04 and the FD590-BS05????
 

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Rod the 04 means it is a made for JD engine and the 05 means it is an engine made for someone else. Since I going through this with my 345 now you may have an engine with a bad camshaft but with low oil it could be something else. Roger
 

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318 W/ 48" deck, hyd tiller, 49 snowblower, 519 cart. Traded in
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HI, Roger Thanks I'm going to pull the engine out and take off the pan and see what mess I have to tell the owner. I'm sure that the wiring harness on the engine will be deferent from one to the other with the BS04 and BS05 engines

Thank You
Rod
 
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