1976 Bobcat 610/VH4D quits when jostled around....any suggestions?

[HamberHead]

New guy here....if this is in the wrong spot please point me to the right spot!

Have run this old guy around the property for about '07 with plenty of repairs along the way.
Just gave him a 1 wire alternator, so got plenty of juice. Spacers under the plugs cause it was changing its own gap, and it likes a quart of oil with each fill up!!!!! (Blue haze to exhaust...)

So maybe this engine is just plain so loose that things aren't working together as they should?

Some have suggested the carb float my be getting stuck or the float pivot is worn?

Any suggestions would be greatly appreciated!
And Thanx in advance too...

 

[foton]

I would think it is a electrical problem in the ingition. like a loose wire. but that is just a guess. if the pistons are hitting the plugs and changing gap , how noisey is that engine? I am trying to vision how much rod slop there would be to do this. I would think more likely it has the wrong reach plugs in it . but that is also a guess. if you were thinking of a rebuild I would think sooner is better than later when it comes apart and becomes just a parts engine.

 

[HamberHead]

Thank you for your input!

I have been chasing this for some time now. Replaced the coil, ballast resistor, correcting wiring as I go, but this one has so much use on it that the wiring is definitely a potential source. I've also tested the head temp sensors without finding any issues.

Do you know of anything in the oil system that might cause this symptom? Like a low pressure sensor that might cause a cut out.

What I'm watching now is it will restart and run just fine after about 1-2 hours which is leading me to believe heat or flooding issues. Maybe a carb rebuild is in order.

Offhand, does anyone have a good average what a rebuild would cost to do myself? (I have done a couple basic V8 auto engine rebuilds in my years!)

 

[ZekeSkyree]

What motor is in your skid steer?

 

[HamberHead]

VH4D Wisconsin Air Cooled 4 cylinder, carb cleaner reveals the carb has been rebuilt, most likely at a Bobcat dealer service when I first got it (2007) and put tires on it.

I have since found the air cleaner cartridge was 100% blocked, the end cap was full of dirt & clippings.

New cartridge coming today.

Wondering if the jostling around would shake up the end cap filth enough to block airflow and cause the engine to choke out and flood...... lets see what the new cartridge does for me!!!

 

[HamberHead]

FYI to anyone with the HD air cleaner on an old 610........Amazon has the HD cartridges selling for $18.88 delivered out the door!

I thought that was a great deal these days for a complex assembly like that. Just sayin'!!!!!!!!!!!!!!!!!!

 

[Donni]

I have a 610 i have owned several they all do this from time to time i think it is the float it bounces around or you might try electronic dist. i havent found a cure!

 

[ZekeSkyree]

VH4D Wisconsin Air Cooled 4 cylinder, carb cleaner reveals the carb has been rebuilt, most likely at a Bobcat dealer service when I first got it (2007) and put tires on it.

I have since found the air cleaner cartridge was 100% blocked, the end cap was full of dirt & clippings.

New cartridge coming today.

Wondering if the jostling around would shake up the end cap filth enough to block airflow and cause the engine to choke out and flood...... lets see what the new cartridge does for me!!!

Sounds like you found it. Might want to do a full maintenance on the old girl. On those older models, think simple.

 

[HamberHead]

Thanx all for your wisdoms!

Came real close to a Pertronix upgrade when found the tired coil, had the coil, and it ran again so had to get back to the job.

Donni - Which model Pertronix worked best on the 610/VH4D for you?

Also, how important is having the breather on the oil fill tube VS. a typical oil cap that seals?????

Still on it!!!!!!!!!!!!!!!

 

[lmcl123]

I restored a 1974 610 a couple of winters ago. I still have the problem you have when hitting bumps. It is most likely a float and /or fuel seat issue. If your getting blue smoke and replacing oil that often, you should rebuild it. I live in Alaska where prices (machine shops, parts shipping) are higher. I think I had $2000-$2500 in mine. Mine was bad though. I had to machine the heads, cylinders, crank shaft, new pistons, rods, rod guides, etc. If your going to do it, pay the extra for everything so you don't have to go in again. AND, don't forget to reinstall the internal oil plug that you can take out to clean the tube that supplies oil to the spray nozzles, or you'll have to rebuild it a second time. I'm not saying I DID THAT, I'm just saying it could happen the first time you rebuild one of these
Also, If you rebuild it, Rock Creek Consulting, out of PA has everything for wisconsin engines, the best prices, and shipping, Good luck

 

[T-rustyfix]

Sounds like you found it. Might want to do a full maintenance on the old girl. On those older models, think simple.

I had this same problem with my OMC Mustang 1200 (also VH4D). It ended up being a misshapen float bowl. Along the way, someone had used a gasket that was too thick and over tightened the ears of the carburetor halves. When a new gasket was installed, the gap between them sucked air, and the carb adjustment was way off. Whenever I would go over a bump, the fuel would jostle out and she would choke and die. I sanded the bowl upside down on a flat workbench with some 150 grit sandpaper, re-assembled, installed, and she now runs better than ever.

 

[T-rustyfix]

Sounds like you found it. Might want to do a full maintenance on the old girl. On those older models, think simple.

here are some pics

 

[T-rustyfix]

@ Hamberhead: I installed PerTronix Industrial Distributors D41-09B on my VH4D and never looked back. Consistent and durable, no points to adjust and fiddle with.

 

[2bobcats]

could be vapor lock as the metal fuel lines don't get much air circulation around them. A common problem. Could try an electric fuel pump . Napa has them for it .Good luck

 

[HamberHead]

Thanx again to all that are contributing ideas and support.

Corrected the air cleaner issues. Turns out the filter cartridge I found in it (completely black with filth), was signed & dated by the mechanic when he put it in.......IN 1984......and the end cap hade a full measuring cup of dirt in it too. Maybe the jostling caused the end cap dirt to bounce up & clog the bypass vent?

It was starting great, but I was not using it, just starting to make sure it would. When I went to use it, picked up one bucket of soil, got jostled around and it quit. Has not started since. So I pulled the carb off to ensure it was a Zenith, soaking/cleaning it now while the rebuild kit with new float is shipping here. Hoping to find something with the needle and float that would indicate an issue.

Getting burnt out on this troubleshooting too..........

 

[DirtRodeo]

On my 743 diesel, I had a pin hole leak in the fuel line. Bubbles would accumulate in a high spot in the fuel line. When the skidsteer tilted front or back the bubbles would move and kill the engine. You might replace any rubber fuel lines and make sure that they're properly clamped.

 

[ZekeSkyree]

You are lucky now that it completely dead. Intermittent failures are a b@tch to find/fix.

Back to basics. Do you have spark? Are the plugs wet (flooding?). Getting gas to the carb? Will it start with a shot of starting fluid?

Start simple!!!

 

[T-rustyfix]

Be advised that when rebuilding a Zenith, the new float needs to be bent significantly to keep it from interfering with the forward wall of the inside of the bowl. It takes some patience and maybe some marker on the edges to see if it is touching the side.

 

[HamberHead]

Lovin' the responses, keep 'em coming.

Fuel lines will be changed as a matter of principal. Currently being held hostage by a late Amazon delivery.............Grrrrr! Thanx "DirtRodeo".

The float rubbing could be a life saver, Thanx "T-rustyfix".

Carb tag was in place so a kit for that carb number is coming. Interesting note on disassembly, the four main body screws were not tight, no "crack" and then they unscrewed. Took no effort at all. Also, there was no wire clip holding the bowl's fill needle valve to the float assembly plate.....oddly some YouTube videos show the clip and others do not. The carb tag is stamped "LZ 63 2" and "12253". Is that clip supposed to be in there? Also found the rubber tipped bowl needle (visible wear) which makes me wonder if it was getting hung up cause the clip was not in there? The needle to bowl contact point on plate showed a visible wear spot and a slight arc to the plate.

Anyhow, think Im going to put the clip back in after I find one. I like the idea of the float and needle having positive engagement up and down.

Any thoughts out there?

 

[T-rustyfix]

sounds like you have a similar issue. Loose gasket is a big deal for these carbs. I still recommend running the bowl over some sandpaper to confirm flatness. Also, there is a specific distance from the bottom of the floats to the face of the carb edge when adjusting them. If I remember correctly, it is 1 5/16ish for mine. I use a small paper square from one of my carb repair kits to measure each side to get them even, then a lot of bending, adjusting, and reassembling with the new needle installed. I recommend the clip as it helps control the needle when the machine is on an incline or jostling around (maybe a hint at the cause here). Not sure about the tag. Might be original, might not.