How does the Throttle work on a pressure washer?

[danny_barkley]

I got a Harbor freight Motor to replace the Honda that dunped a valve on my Pressure washer.

But there is some kind of arm gadget on it that I think ramped the throttle when you pulled the trigger. It wasn't plumbed into the wand, it was some arm gadget on the side of the motor.

How do these work and can I replicate it on my HF Predator motor?

 

[crguy]

My Landa pressure washer with a Honda motor runs at a constant speed all the time.

 

[gdocktor3]

I got a Harbor freight Motor to replace the Honda that dunped a valve on my Pressure washer.

But there is some kind of arm gadget on it that I think ramped the throttle when you pulled the trigger. It wasn't plumbed into the wand, it was some arm gadget on the side of the motor.

How do these work and can I replicate it on my HF Predator motor?

Can you take pictures? Are you sure that isn't the manual throttle lever? With like a turtle to rabbit type sticker under it? Now that you mention it though, I think some motors do automatically rev higher when needed. I remember seeing the throttle opening and closing on its own with a spring connected to it on a log splitter.. Or snow blower... Or maybe it was a power washer...

Update - Evidentially Honda motors do have an "auto throttle" feature. Unlike other brands where the motor runs at one constant rpm, the Honda will call for more power when needed. The HF and like brand power washers do not use the auto throttle. If you read the specs on this motor from Honda, you will see the "auto throttle" feature as well as "power washer control" features. I'm no Honda Technician, but I don't think the power washer would work very well with that HF motor. http://engines.honda.com/models/model-detail/gcv190

 

[stikman56]

Can you take pictures? Are you sure that isn't the manual throttle lever? With like a turtle to rabbit type sticker under it? Now that you mention it though, I think some motors do automatically rev higher when needed. I remember seeing the throttle opening and closing on its own with a spring connected to it on a log splitter.. Or snow blower... Or maybe it was a power washer...

Update - Evidentially Honda motors do have an "auto throttle" feature. Unlike other brands where the motor runs at one constant rpm, the Honda will call for more power when needed. The HF and like brand power washers do not use the auto throttle. If you read the specs on this motor from Honda, you will see the "auto throttle" feature as well as "power washer control" features. I'm no Honda Technician, but I don't think the power washer would work very well with that HF motor. http://engines.honda.com/models/model-detail/gcv190

I replaced the tired 6hp Tecumseh after it threw a rod on my Roto-spader, with a HF Predator 212CC engine. I couldn't hear the rpm's change when I dropped the tiller in the dirt. I was impressed with the power it had. I think it might do just fine on a pressure washer, couldn't say for certain though.

 

[danny_barkley]

Update - Evidentially Honda motors do have an "auto throttle" feature. Unlike other brands where the motor runs at one constant rpm, the Honda will call for more power when needed. The HF and like brand power washers do not use the auto throttle. If you read the specs on this motor from Honda, you will see the "auto throttle" feature as well as "power washer control" features. I'm no Honda Technician, but I don't think the power washer would work very well with that HF motor. http://engines.honda.com/models/model-detail/gcv190

The pump is a pump is a pump.

I got some oil to change it out in the pump, and was planning to bolt up to the Predator

Here is a pic of the arm on it that does the auto throttle thing.

 

[danny_barkley]

I'm reading about people that had issues with the governor/auto throttle and I may have some problems getting this to work right.

 

[justme-]

I am a Honda technician... The " auto throttle " thingy pointed to in the picture is the governor arm. All small engines have one. Don't mess with it. Improperly set you will have tons of issues from surging to over speeding resulting it destroying the engine. The governor is already set when you buy the engine. The Honda GCV linked above mentions auto throttle....if you have ever used a lawn mower that has no throttle lever... Just hold the handle, pull the rope and it starts.... That's auto throttle. Nothing special, just marketing terms.

If the pump will bolt on to the predator engine, shaft is same size, and orientation is correct for the pump (vertical pump on vertical engine, horizontal on a horizontal with breather up) hook it up.
Pressure washers have an unloader valve that allows water to recirculate through the pump when the gun is not squeezed. This valve is also used to set the pressure/cut out for the pump/engine combination.
Personally speaking, I never recommend repowering a pressure washer...not generally worth the engine cost and work, as simple as it is, especially setting the pump to the new engine. Done properly requires inline high pressure gauge .

 

[danny_barkley]

I am a Honda technician... The " auto throttle " thingy pointed to in the picture is the governor arm. All small engines have one. Don't mess with it. Improperly set you will have tons of issues from surging to over speeding resulting it destroying the engine. The governor is already set when you buy the engine. The Honda GCV linked above mentions auto throttle....if you have ever used a lawn mower that has no throttle lever... Just hold the handle, pull the rope and it starts.... That's auto throttle. Nothing special, just marketing terms.

If the pump will bolt on to the predator engine, shaft is same size, and orientation is correct for the pump (vertical pump on vertical engine, horizontal on a horizontal with breather up) hook it up.
Pressure washers have an unloader valve that allows water to recirculate through the pump when the gun is not squeezed. This valve is also used to set the pressure/cut out for the pump/engine combination.
Personally speaking, I never recommend repowering a pressure washer...not generally worth the engine cost and work, as simple as it is, especially setting the pump to the new engine. Done properly requires inline high pressure gauge .

Hi,
Thanx for the great info.

I never used a Lawn Mower with no throttle, so there ya go, I'm ignorant.

So I decided to repower this washer because the Italian pump on it is supposed to be so good. Otherwise I would have booted it to the curb.

Everything does mate up perfectly, checked that before I bought the motor.

So it should work OK?

 

[justme-]

So it's an "AR" pump...like all companies they make some good and some junk. My rental units are AR brand pumps....made in China. But the have a 5 year warranty under rental duty or I wouldn't have them.

Bolt everything up, hook up water, and see how it runs. There is nothing engine side to adjust or touch, the only question is setting the unloader to let the pump and engine work well together.
Simple answer tho is if it runs and doesn't cause the engine to hesitate or stall don't worry about it. If it does cause that PM me and I'll help you sort it out as best as possible.

 

[danny_barkley]

So it's an "AR" pump...like all companies they make some good and some junk. My rental units are AR brand pumps....made in China. But the have a 5 year warranty under rental duty or I wouldn't have them.

Bolt everything up, hook up water, and see how it runs. There is nothing engine side to adjust or touch, the only question is setting the unloader to let the pump and engine work well together.
Simple answer tho is if it runs and doesn't cause the engine to hesitate or stall don't worry about it. If it does cause that PM me and I'll help you sort it out as best as possible.

Hopefully I got a good one.

I'll attach photos.

I had bought some oil for it, do I just take the cap off the top, measure how much oil comes out and replace it?

Glad I posted here and got you on this to help me out!

 

[justme-]

That would be the best way if it has an opening vent, many home duty units are sealed. In general home duty units will never get it need that oil changed as they wear out or get broken before it's needed.

In all honesty this is a typical home duty AR pump available on many big box store pressure washers. It's a higher lever of home unit over the devilbiss spider looking vertical ones or the really tiny ones. The original unit probably retailed for around $450 with the Honda.

If you want to make it last get a screened hose washer for the inlet. Make sure not to start it without water flowing, and keep it from freezing. Pressure washer pumps are not really repairable. Many require special tools or knowledge and quite simply if one internal part fails, others are damaged.

 

[fatfillup]

Industrial pressure washer pro here. Justme was pretty much right on. There are other Italian made pumps other then AR. General, Comet, Interpump, Legacy and a few others come from Italy.

Justme was absolutely correct that most companies make some good and some cheap pumps. I would say without exception, any pump connected to a consumer grade motor is a cheap pump. Some are better then others. What is more important is how you treat it. First and this is critical, don't let the pump run in bypass for more then 30 seconds. Bypass is with the machine running and the trigger shut off. Heat will build up in the pump and prematurely wear the packings. Second, don't let the pump freeze with water in it, it will break. Third, don't ever loan it out.


As to auto throttle, there are some mechanical devices that connect to the pump and will operate a cable to idle the machine down when the trigger is shut off. More trouble then they are worth and don't know a manufacturer that uses them anymore.

Let the motor run at a fixed speed, they don't mind. You can slow the motor down if you want less pressure.

 

[fatfillup]

Pressure washer pumps are not really repairable. Many require special tools or knowledge and quite simply if one internal part fails, others are damaged.

I agree that home owner pumps are not repairable, but industrial pumps are quite repairable.

 

[danny_barkley]

Thanx guys. I already do religiously all the stuff you guys are talking about.

I was disappointed when the top end on the motor bit the dust and figured with all my HF coupons and sales it would cost me like $80 to put the Predator motor on it which has a great reputation.

I had heard that this pump is rebuild-able and good for 800 hours. So that's why I gambled on it.

 

[danny_barkley]

Here's the oil drain.

There was only 1.5 oz drained, temp is about 90 degrees

How should I fill to the proper amount.

 

[danny_barkley]

Here's the oil drain.

There was only 1.5 oz drained, temp is about 90 degrees

How should I fill to the proper amount.

I took off the top cap and the side "sight" cap

Rolled it around for quite a while a few times and let it gravity drain directly out the hole

Did this a few times over about an hour

 

[redmondjp]

You put the sightglass lens back on, level the unit, and fill until you are about half-way up the sightglass (typically, it could be slightly less - check instruction manual). Don't overfill.

 

[danny_barkley]

You put the sightglass lens back on, level the unit, and fill until you are about half-way up the sightglass (typically, it could be slightly less - check instruction manual). Don't overfill.

No sightglass

 

[redmondjp]

No sightglass

Oh sorry, misinterpreted what you said.

How high up on the side is that plug? If it's not right at the bottom, typically you leave that plug open, and fill from the top until it starts running out the side opening.

 

[danny_barkley]

Oh sorry, misinterpreted what you said.

How high up on the side is that plug? If it's not right at the bottom, typically you leave that plug open, and fill from the top until it starts running out the side opening.

That was my plan if someone doesn't come up with a better/right plan!

It's where you would expect to find it on a transmission, about half way up the side.

But I think if you look online, the "drawings" have a sight glass there.

I was surprised how little oil I got out of it. But it's been apart a while so who knows. I'm just now getting back on this project...

Just re-read what I said and what you responded too. Sorry, I wasn't clear. I meant "sight" cap like you would find on a car transmission. That was not clear of me.