Log Splitter stalling out.

trigger_andy · May 30, 2016, 03:24:32 PM

Hello,
been a lurker for a while and really enjoy this site, so much so I wanted to build my own Log Splitter and I've purchased my first Chain Saw.

So I've built my Log Splitter now, its a Honda GX390 running a 16Gal/min Two Stage Pump. The Ram Body is 3.3" OD and the Piston exiting the Body is 1.5" OD.

The issue Im having is as soon as the Ram see's any load the Engine almost instantly dies, its within a second, two max. Ive stripped the Carb and its clean and free moving, Ive tried running the Engine with the Air Cleaner removed and it makes no difference. Spark Plug is an NRK and looks clean and well gapped. Ive tried holding the throttle fully open and running at full RPM's and this does not help either. When the Splitter sees resistance the Engines Governor is opening the Throttle so that's not an Issue either. :/

Before I hooked the GX390 up I had a small Hydraulic Unit with a GX340 running the Splitter (through the same directional Spool) with no issues so Im really stumped as to whats causing this issue. Ive also tried the Spools PRV at minimum and maximum.

Any assistance would be greatfully recieved.

Andy (Scotland)

r.man · May 30, 2016, 04:21:11 PM

Sounds like a motor pump mismatch at first glance. Check your basics, motor hp, hp required for that pump, rotation of pump matching motor. Possibly a bad pump or not two stage?

wndwlkr65 · May 30, 2016, 04:29:49 PM

Sounds like your pump is not kicking down. Right next to the inlet on the pump you will see a cap nut. Take that off & you will see a flat head screw. Turn that screw counter clockwise 2 turns & try that. That lets your pump kick down to low volume High pressure quicker. You can adjust it to where you like it from there.

trigger_andy · May 30, 2016, 06:15:53 PM

Thanls for the reply.

The Pump is matched to the Engine. At least the Website I bought it from stated that.

http://www.flowfitonline.com/hydraulic-pumps/two-stage-hilow-gear-pump-kits/hydraulic-16-gpm-two-stage-hilow-pump-cw-bell-housing-engine-kit

Quote from: r.man on May 30, 2016, 04:21:11 PM
Sounds like a motor pump mismatch at first glance. Check your basics, motor hp, hp required for that pump, rotation of pump matching motor. Possibly a bad pump or not two stage?

trigger_andy · May 30, 2016, 06:19:14 PM

Hey, thanks for the reply as well, its appreciated. In the link is my Pump, is what you mention applicable to this pump?

Cheers,

Andy

Quote from: wndwlkr65 on May 30, 2016, 04:29:49 PM
Sounds like your pump is not kicking down. Right next to the inlet on the pump you will see a cap nut. Take that off & you will see a flat head screw. Turn that screw counter clockwise 2 turns & try that. That lets your pump kick down to low volume High pressure quicker. You can adjust it to where you like it from there.

trigger_andy · May 30, 2016, 06:40:36 PM

Well, I tried turning out the flat head screw initially two then tree turns after the engine had warmed up and its still the same. :(

Andy

wndwlkr65 · May 31, 2016, 12:02:34 AM

Well, I would take that flat head screw all the way out, then you will see a spring & take it out & there will be a steel ball next, make sure that steel ball is not stuck on there & not releasing. I suppose it's a new pump from the link & even so some times setting on a shelf for long periods of time will let the relief ball gum up. I've seen splitters that have sit 3-4 years & have this problem. just clean it up & it should work fine. Don't expect lot's of power from a 3" cylinder. With that said it should split anything you want when you get your pump working. My splitter runs a 3.5" cylinder & it works fine. if you take it apart just put a clean bucket under to catch any fluid & reuse it if ya want. Hope this helps.

trigger_andy · May 31, 2016, 05:16:21 AM

Thanks again for the reply.

I'll give that a try this afternoon.

Thanks again.

Andy

trigger_andy · May 31, 2016, 05:50:13 AM

Could another potential issue be the size of my Oil Tank? Its only 40l, when running the fluid level never seems to drop but Ive been told I'd need a much larger tank by some and by others it will be fine. Just thought I'd throw that one out there.

Cheers,

Andy

wndwlkr65 · May 31, 2016, 07:48:50 AM

If thats 40 liters then that should be fine

trigger_andy · May 31, 2016, 08:32:33 AM

Yes liters sorry. :D

Ok, thats good to know thanks. I'll check the Pump soon as I can, I really hope its the issue.

Thanks again,

Andy

pineywoods · May 31, 2016, 09:13:14 AM

Most likely the pump. I had a brand new one do the exact same thing. took it apart and found it full of aluminum chips from the machine process. Tear it apart, there's nothing delicate or complex in there. It's just 2 gear pumps and a pop-off valve.

trigger_andy · May 31, 2016, 05:32:28 PM

Pulled the Screw out and the Spring, behind it was a poppet which looked clean and the oil flowed freely and there was no evidence of swarf or gumming up.

I'll reluctant to strip the pump as its brand new and would void its warranty but needs must I guess?

Does the Oil Tank need to be higher than the Pump to gravity feed it? Currently the top of the Tank is aligned with the top of the Pump so I guess there is little gravity feed going on?

I have a new Spool coming tomorrow, hopefully that will help but Im not holding out much hope. :(

Andy

Quote from: wndwlkr65 on May 31, 2016, 12:02:34 AM
Well, I would take that flat head screw all the way out, then you will see a spring & take it out & there will be a steel ball next, make sure that steel ball is not stuck on there & not releasing. I suppose it's a new pump from the link & even so some times setting on a shelf for long periods of time will let the relief ball gum up. I've seen splitters that have sit 3-4 years & have this problem. just clean it up & it should work fine. Don't expect lot's of power from a 3" cylinder. With that said it should split anything you want when you get your pump working. My splitter runs a 3.5" cylinder & it works fine. if you take it apart just put a clean bucket under to catch any fluid & reuse it if ya want. Hope this helps.

wndwlkr65 · May 31, 2016, 07:22:24 PM

Maybe your valve is plumbed wrong, most valves are marked in & out. just throwing that out here. your valve may be upside down for all we know. Pictures would be a +.

trigger_andy · June 01, 2016, 05:18:59 AM

Thanks for the suggestion. Its things like this that could easily catch me out. :D Im sure it is right but I'll double check. I'll take some pics too, and thanks again.

Andy

Quote from: wndwlkr65 on May 31, 2016, 07:22:24 PM
Maybe your valve is plumbed wrong, most valves are marked in & out. just throwing that out here. your valve may be upside down for all we know. Pictures would be a +.

trigger_andy · June 01, 2016, 07:03:01 AM

You where right. Total School Boy error and I feel really stupid now. :( Thanks for the suggestion, the Splitter is working as it should now but is still not splitting my Beach Wood, grrrrrr. Birch seems to be ok but I guess I need bigger Ram next.

Out of interest since Ive lost where my Pop Off was positioned what indication do I have that the pump is going to Stage 2?

Andy

Quote from: wndwlkr65 on May 31, 2016, 07:22:24 PM
Maybe your valve is plumbed wrong, most valves are marked in & out. just throwing that out here. your valve may be upside down for all we know. Pictures would be a +.

Ivan49 · June 01, 2016, 01:17:14 PM

You must have something else wrong on your splitter. I use a 3 inch ram and I can split knotty oak with mine. I use the 16GPM 2 stage pump on mine also. Your tank should be higher than your pump to get proper oil flow. On mine my my pump is located about a 1/3 of the way up from the bottom of the tank

trigger_andy · June 01, 2016, 02:24:48 PM

Hmmm, ok, Ill have to try something other than this knotty Beach round and Birch. :D The Beach was left by the last owners of ths house, Im assuming as its not splitting, but I could be wrong.

I'll have to take some pictures of my set up but as its a Trailer mounted Splitter its not really practical to have the Tank any higher than it is. I also think my bodged knife is maybe not thin enough? Basically all the parts where scrap, free or nearly free.

Thanks for the reply. Let me know if you see something obvious.

Quote from: Ivan49 on June 01, 2016, 01:17:14 PM
You must have something else wrong on your splitter. I use a 3 inch ram and I can split knotty oak with mine. I use the 16GPM 2 stage pump on mine also. Your tank should be higher than your pump to get proper oil flow. On mine my my pump is located about a 1/3 of the way up from the bottom of the tank

wndwlkr65 · June 01, 2016, 02:47:41 PM

Glad you got it working, on the kick down relief valve just turn it in fairly tight & if your motor starts to bog down just back it out till you like it. with that motor you could run in high flow low pressure alot, it will make your cycle time faster. without a pressure gauge the only way to tell is to watch the ram move. as far as your tank mounting my tank is 19" below my pump & I have never had a problem. If you find wood it won't split try moving the wood off to one side & take a little at a time & work your way around it. Looks like a nice homebuilt splitter !

trigger_andy · June 01, 2016, 03:31:04 PM

Thanks for the reply.

I'll take your advice on. Thanks again.

Quote from: wndwlkr65 on June 01, 2016, 02:47:41 PM
Glad you got it working, on the kick down relief valve just turn it in fairly tight & if your motor starts to bog down just back it out till you like it. with that motor you could run in high flow low pressure alot, it will make your cycle time faster. without a pressure gauge the only way to tell is to watch the ram move. as far as your tank mounting my tank is 19" below my pump & I have never had a problem. If you find wood it won't split try moving the wood off to one side & take a little at a time & work your way around it. Looks like a nice homebuilt splitter !

Gearbox · June 01, 2016, 05:19:12 PM

Befor you spend $$ clean up the welds on that wedge . fill in the welds and grind smooth fill again till there is nothing for the wood grain to catch on

Al_Smith · June 01, 2016, 08:08:55 PM

Your wedge design could stand some improvement.If you had left the narrow portion then put the "wings" farther back it would have been about right .With only a tad over 3 inch bore you need more of a knife edge prior to spreading the round apart .

I don't know what type valve you have but most have relief built into them.You might try lowering the pressure until you can get the pump to shift to lower pressure.

trigger_andy · June 03, 2016, 04:36:22 AM

Thanks for the tip.

I'll do that.

Quote from: Gearbox on June 01, 2016, 05:19:12 PM
Befor you spend $$ clean up the welds on that wedge . fill in the welds and grind smooth fill again till there is nothing for the wood grain to catch on

trigger_andy · June 03, 2016, 04:38:10 AM

Thanks for the info.

I may redesign it at a later stage or buy a made one, there seems to be plenty in the US but little to none suitable in the UK.

In the mean time I'll follow Gearbox's suggestion and just try and improve on what I have.

Cheers,

Andy

Quote from: Al_Smith on June 01, 2016, 08:08:55 PM
Your wedge design could stand some improvement.If you had left the narrow portion then put the "wings" farther back it would have been about right .With only a tad over 3 inch bore you need more of a knife edge prior to spreading the round apart .

I don't know what type valve you have but most have relief built into them.You might try lowering the pressure until you can get the pump to shift to lower pressure.

trigger_andy · June 03, 2016, 02:11:33 PM

Well I narrowed the Wedge and ground down the Welds and the Splitter is going though everything. :O Even cutting 3" of Beach across the grain. Happy days.