GX 630 Engine

Steven Button

Administrator


Putting a replacement engine on my Largo skid (Briggs died at 3700 hours) - figured I would document it here, and more to the point, ask for advice on how to get it all done. Perhaps the thread will help others in the future.

Will be putting a different oil filter adapter on this one to allow a side mount muffle to be installed.
 

Hardwaresteve

New member
None, I have built many units and I have never put or seen anything on the shaft or key. The biggest problems you will have is the depth of the motor compared to the Briggs, and you will prob have to get a different pulley or bushing for the pulley, I can't remember off hand if they are different sized shafts. Aside from that the voltage rectifier needs to be as far from any heat sources, like the pillow muffler.
 

tomtucson

New member
I have never put anything on a key / keyway. I have my mufflers remote mounted using flex exhaust and it's about a thousand degrees cooler around the engine and pump. If you have a spot it was very easy and also no more broken exhaust bolts!!
 

Steven Button

Administrator
Thanks guys... I got the correct pulleys and bushing from Paul at powerwashstore.com.

Got the oil filter base switched out for the new one ...



Got the side mount muffler put on...



Will post pictures later taking pulley off the pump.

Anyone know if I can move the fuel line to the other side of the engine? I've not taken the air filter housing off yet to check what's going on underneath yet!
 

Hardwaresteve

New member
Pretty sure it uses the same fuel pump like you see on a Briggs, not sure about rerouting it, but you can pull fuel from further than Honda recommends. Seems like you need a 6mm and a 10mm to get under there to check it out. Looks like your making progress, looking forward to seeing the end result, good luck!
 

tomtucson

New member
How was it changing the oil filter mount? I saw on the honda site that the new engines have a one piece cylinder and head, timing, and are hemis ! Pretty impressive, although the timing is kind of mute with running at one speed. I see the gx690 on machines running 8 @3500, 9 @3000 and even 10 @3000 - seems like some free horsepower.
 

Steven Button

Administrator
How was it changing the oil filter mount? I saw on the honda site that the new engines have a one piece cylinder and head, timing, and are hemis ! Pretty impressive, although the timing is kind of mute with running at one speed. I see the gx690 on machines running 8 @3500, 9 @3000 and even 10 @3000 - seems like some free horsepower.

Oil filter mount was a breeze - literally bolt off, insert rubber seals, bolt new one on!
 

Steven Button

Administrator
Ok... Jumping way ahead (will post pics and progress later, to busy just now). Got it all put together and wired up to the burner, set pressure at unloader, and was running under load for 5 minutes to test.

While testing I was getting alternating screeching and pressure loss... Turns out the 1/4" key stock has come out and the bushing is slipping on the shaft. As suggested, I didn't use any adhesive, just tightened down the set screw in the bushing on top of the key.

What could I have done wrong? Any suggestions on what to do to avoid this happening again - will give it another bash tomorrow.
 

Hardwaresteve

New member
Sounds like the bushing is the wrong size, or the key was wrong size. I think Honda uses a 1" bushing, not 100% sure about that however. Is it possible you can post a picture of how you have the pulley assemble on the shaft?
 

tomtucson

New member
We're talking about a split taper bushing? When they are cranked down on the shaft I swear they would turn the belts without the key. 3 bolts? Did they tighten until they felt like they couldnt go any tighter without strtching/breaking the bolts? If not it sounds like the wrong bushing, any markings?
 

Steven Button

Administrator
When I put the bushing on, do I need to use a rubber mallet to get it on tight? I just had it hand tight... Could that gave been the problem?
 

Hardwaresteve

New member
I have never had to hammer one on...Is this a two piece setup, a pulley that is separate from the bushing? If so the bushing, (small insert) should have three bolts, 7/16" head on them that you tighten the pulley too...working your way around it, don't tighten one bolt all the way then another. As you tighten the bolts the pulley and the bushing are jambed together and the key would be locked in place. The only other thing you could have would be a one piece setup, where you tighten an allen head bolt down onto the key causing it to jamb as well, however I wouldn't recommend that style personally. For a visual reference look at this catalog page 95 is the first style, page 92 has the second.http://www.pressurewashercatalog.com/#?page=94
 

Steven Button

Administrator
Steve, separate pulley and bushing, the bushing gas a set screw as well... You may have given me the solution though. There are 2 bolts on this setup, however, I did not tighten the bolts after I placed it on the motor shaft. I tightened them before sliding into shaft.

If I tighten in the shaft, should that pull it all together to keep the key in place?

Thanks got your time and input.
 

Hardwaresteve

New member
you should only be able to tighten the bolts down on the shaft....if possible take a pic with your cell phone and send it to me, something doesn't sound right, if you tightened the bolts down then the bushing should not have been able to slide over the shaft...unless you left them very loose, and be careful to not over tighten those bolts cause I have broken them off more than once in the past.
 
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