Iwata Powerjet Pro repairs

jord001

Air-Valve Autobot!
Hi peeps, I've had a Powerjet Pro for a while. It's started making a louder than normal noise of late. It still charges the airtank right up to full but its makes a clacking noise after several seconds until it switches off. It sounds like a bearing going in an engine so I thought its time for some investigation.

I've finally managed to get time to have a look at it so I've taken off the end covers ( its a twin piston compressor ) to see whats in there. When opened you can see the crank fitted on a shaft with a piston on top, nothing else in there. I checked the back one (which is easier to get to) and everything looks and feels fine, the front however has some play in it when imove the crank and I am assuming it's the bearing. There's only a circlip holding it together on the shaft so I'm hoping in the week I will get time to remove the clip and the head to get the piston out and I am hoping it's going to be that easy. I can then check the bearing number and get a replacement.

When I get to do it I will take pics and post them up here in this thread incase someone else has a similar issue in the future. I am assuming that all small oil less compressors are going to be similar so this may save peeps some cash if their compressor goes belly up.

Till next week.....

Lee
 
Cool! Is it a needle roller bearing? And are you talking about the lower con rod bearing?
Another weak spot is usually up in the piston pin, often the pin wears the piston hole and makes slop on small motors/ compressors since its the only steel on aluminum joint and they aren't press fit. Just something to look out for
 
Interesting one Lee! I’ll be saving his thread Mate.


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Cool! Is it a needle roller bearing? And are you talking about the lower con rod bearing?
Another weak spot is usually up in the piston pin, often the pin wears the piston hole and makes slop on small motors/ compressors since its the only steel on aluminum joint and they aren't press fit. Just something to look out for
I love when robby talks about mechanical stuff. I feel like I am in Star wars talking to Jedi Master lol
220px-Yoda.JPG
 
Cool! Is it a needle roller bearing? And are you talking about the lower con rod bearing?
Another weak spot is usually up in the piston pin, often the pin wears the piston hole and makes slop on small motors/ compressors since its the only steel on aluminum joint and they aren't press fit. Just something to look out for

@Robbyrockett2 It looks like a standard bearing around 20mm diameter and yes im talking about the lower conrod bearing or as we would call it over here in England "the big end" and we call the bearing at the piston end if it has one the little end. It feels like play at the bottom so I hope i'm on the right track. Looks like it just presses into the conrod but I won't know properly till I get it off. I will document it as I strip it. Thankfully i'm ok with mechanical stuff and have stripped my Honda 125 down several times as well as my first Mini 1275 and my old Landrover Discovery so I think I will be able to do this hopefully without too much trouble.

Lee
 
Cool, it'll be interesting to see.
I'm sure you're on the right track.
I'm just curious how this one is set up.
Sounds like its bigger than I thought it would be.
So by standard , are you saying its like a ball race?
 
Simple tools are needed. They were allen keys / hex wrenches, Posi + screwdriver, Circlip pliers torch and Specs I couldn't see without them it's small stuff..


First thing was to take out the 3 screws from each side of the case.
pic01.jpg

Then the plan was to take just the one head off but as they are joined i took both off so I didn't have to undo any pipes
pic02.jpg

This is what's inside. 2 simple pistons with non return reed valves on top, nothing too technical.
pic03.jpg

Then I removed the end covers, nothing special here either, 4 screws and a card gasket underneath.
pic04.jpg

This is the bearing that's in question. Same each side They're mounted on a double ended shaft secured by a small circlip
pic05.jpg pic06.jpg pic07.jpg

Once the clip is removed I removed the sleeve from the top of the piston just a push fit.
pic08.jpg

move the piston to top dead center and then slide it off the shaft. It will then easily pop out of the top of the barrel.
pic09.jpg pic10.jpg
 
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So here it is being removed from the barrel. Simple setup, they're mounted on a double ended shaft with the circlips.
pic11.jpg

Here's the counterbalance that's behind each piston and conrod. That is attached with a simple grub screw onto the shaft. There's a flat on the shaft for the screw to tighten against.
pic12.jpg

Here is the piston and conrod. It's a simple flat bearing 608Z. Looks like a interference fit but i will have to take it up the garage to remove it in the vice.
pic13.jpg

The other end was checked again just in case, and there is no play int he bearing. I checked by moving the piston from the top.
The other end ( the one we suspected ) has very slight movement when moved the same way.
pic14.jpg pic15.jpg

I've ordered a replacement bearing from eBay ( I ordered 2 ) as a precaution. I will check when they come next week, until then its a waiting game. I will probably pop up the garage shortly to try to remove the bearing (carefully) Don't worry I will take pics. I just hope its not too stubborn or I break something.

I hope this has helped so far.

Updates soon

Lee
 
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The update is a lot quicker than I expected.....

While I was ordering the bearings i noticed some descriptions were for scooter wheels... I thought I ordered a set for my god daughters scooter last year.. had a set of 4 but only used 2. I wonder if they're the same? Oooo look they are.. I wonder.....
pic18.jpg

Ok so I wandered up the garage and sorted out 2 sockets, one the same size as the bearing and one that was bigger than the bearing so it could drop into it. Then I popped them into the bench vise and after fiddling with them for what seemed like an age I carefully closed the jaws.
pic16.jpg

OMG it came out much much easier than I expected. BONUS!
pic17.jpg

So before I tried anything else I tried one on the shaft in the compressor, it fits..
Then I couldn't get it back off.. Aghhhhhhhh
Finally after removing the counter balance and farting about for 5 mins getting the bearing back off the counterbalance I popped back up the garage and with the vise I squeezed the new green slime bearing into the conrod. Perfect fit!
I came back down to the house, refitted the piston making sure the valve was the right way round for the head. Reverse of the removal procedure I replaced the circlip, the head and the end covers, plugged it into the power and started it up, almost silent as per normal but more importantly no horrible slapping noise as it charged the air receiver. PSssshhtt, it stopped at whatever psi its supposed to stop at. Silent!

IT'S ALIVE !!

Sorry I forgot to take a pic of the new bearing in the conrod but i'm sure you can imagine it.

I refitted the side casing and 6 screws and that's about it.

Job well done!

How long did it take? Well it probably took about an hour. Most of that time was spent trying to get the circlip off without wearing my glasses.. lol
Over all a pretty simple repair and pretty cheap, the bearings are only £2 so about $3 max and just your time as long as you have the right tools.

I hope this helps someone in the future.

Lee
 
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Awesome work Buddy! That was a proper stroke having the bearings from he scooter too. Massive result and a great SBS too. You made it seem easy Mate!


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Thanks Si, That's cos it was easy. Just fiddly on some bits. I hope it helps someone if they have the same trouble. It seems like its there or the small reed valves on top of the pistons that play up.

All I need to do now is find the quick connects for it so it can be used. Can't remember where i've put them :)

Lee
 
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Pmsl, I will sod off of course.....after I've badgered you til you want to bludgeon me with a blunt object that is lollollol

I wouldn't dare bludgeon you, I'd be burned to a crisp by your guards.. i'd ride down on my bike and fix it really quick. :)

Plus I will have some spare bearings when they come.

Lee
 
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