[maxmetal]

I can't begin to thank all of you guys to chime in (Al, Richard, Mike, John -- I think I got everyone?).

max,
as far as under load -- the KT smokes the worst at idle AND when use the hand lever to engage drive or reverse. Smokes very little when at max throttle and gear already engaged (like when I am in the midst of mowing I never see any smoke screen trailing behind).

if (and you guys have all done a pretty good job of pushing me towards tackling this) I do end up putting in new rings, when I had pulled the heads earlier this year (thinking part of the problem was leaking head gaskets), I removed carbon and the valves looked pretty well worn. Would it make sense to try to do all of that at the same time or do you think the rings and honing/cross hatching would solve 80-90% of the problem?

When it is idling and smoking and you remove the oil filler, do you see puffs of smoke? If so, blowby past the rings.

Does it seem to suck oil in a trailing throttle situation, and then give a big puff of blue smoke as you feed gas, and then the smoke gets less? If so, valve guides.

Regardless, a light hand hone is sufficient if you decide to fit new rings. But I am also now suspecting perhaps a worn valve guide based on what you wrote above.

 

[IL_Gravely8179G]

When it is idling and smoking and you remove the oil filler, do you see puffs of smoke? If so, blowby past the rings.

Does it seem to suck oil in a trailing throttle situation, and then give a big puff of blue smoke as you feed gas, and then the smoke gets less? If so, valve guides.

Regardless, a light hand hone is sufficient if you decide to fit new rings. But I am also now suspecting perhaps a worn valve guide based on what you wrote above.

max, I'll have to check on the 1st situation -- spent all day trying to do the final clean-up, not quite done yet. 2nd situation, yes, I think that's pretty accurate, if I bring it down to idle from full up, it smokes a ton -- then if I go back up to full, get a big cloud of blue smoke which pretty much goes away once revs are up all the way. At full throttle, i notice no smoke whatsoever.

One thing I did today was tried to leave it in gear, full throttle but lower gear so I wouldn't have the engage/disengage/forward/reverse where it seems putting the load on the engine causes a lot of smoking.

max, if I understand the Kohler service manual, I've got to pull the flywheel in order to get the pistons out -- is this a correct assumption? also wondering if I need to do same to replace valves/valve guides?

 

[IL_Gravely8179G]

Here is a Robin I was talking about.
Robin Subaru V-Twin Engine 22 HP OHV EH65 1-1/8" x 4" Shaft #EH650DC4050

This Co. seems reasonably priced .
I have never used them??

Here is there Honda.

Honda Horizontal Engine GX690 Series OHV 12V ES 20 Amp 1-1/8" x 3-1/2" #GX690-TDW

Hi Bruce, that is the engine I was looking at as well (a few other places have as well) -- in addition to the 25 and 28 hp EH72. Wonder if you or anyone knows what those other numbers stand for (DC4050) because I know that is not the same spec/model if you look it up on Gravely site??? I will have to call either Gravely or Robin-Subaru to see if I can find someone to tell me.

The Honda wouldn't be bad but I do like the thought of repowering with an engine type already used in a Gravely -- having the ability to simply drop it in, bolt it up and bolt on a factory Gravely muffler eliminates some of the hassle of trying to get one made.

 

[yamato72]

For some of us the engine internals can be a scary thing to deal with, especially without someone to mentor us. I have a basket case M18 that came on a 16G parts tractor i got a few years ago, had a broken rod and camshaft. I bought a set of heads with pistons and rods in good used condition, need to have everything mic'd and if it checks out, get a set of gaskets and put it back together. I have put it off for 3 years though but I'll get to it someday. Point is, if I was in your shoes and it was in my budget I would do a repower and the ready-to-go Command would be an option for me, as well as a Vanguard or Honda/Subaru with Bruce helping me over the phone.

 

[IL_Gravely8179G]

For some of us the engine internals can be a scary thing to deal with, especially without someone to mentor us. I have a basket case M18 that came on a 16G parts tractor i got a few years ago, had a broken rod and camshaft. I bought a set of heads with pistons and rods in good used condition, need to have everything mic'd and if it checks out, get a set of gaskets and put it back together. I have put it off for 3 years though but I'll get to it someday. Point is, if I was in your shoes and it was in my budget I would do a repower and the ready-to-go Command would be an option for me, as well as a Vanguard or Honda/Subaru with Bruce helping me over the phone.

Hi Yamato72, agree, I've essentially gone it alone with some very good help/advice from the kind folks on this forum!

I am leaning more and more towards re-power; what I am hoping is I can keep the KT17II "alive" through winter and its snowblowing duties -- and in that timeframe, get the details all sorted out for re-power. That would include everything from purchasing the engine, to muffler, electrical layout, etc. Ideally, I get through winter, spring breaks and I have all the hardware needed, pull the Kohler and install the ????

For those that are interested, here is what additional things I've been able to find/research thus far.

1. If going the Robin-Subaru route, there is a Gravely part # (08256000) but more importantly, there is a Robin-Subaru spec # -- the original was EH650DB7510, which was superseded by EH650DB7520.

I called Robin-Subaru today and even though EH650DB7520 does NOT show up on their website anywhere, it DOES show up in their internal system. It is a CURRENT part #! And, they have 3 in-stock!!! When I asked, I was told this wasn't some old engines they had sitting around but was a current engine and -- it comes with a 5 year warranty. In my mind, that and the muffler situation are the 2 things really pushing me in this direction.

Re factory/Gravely muffler for the Robin: can still get one! I confirmed that today too. To me that's a big deal to simply be able to bolt on a factory designed muffler that will work without any hassle of having to get one fabricated.

And regarding the muffler and the Robin-Subaru engines -- that muffler SHOULD work on the V twin series. The Gravely spec is really an EH64, it is 20.5 HP (which is a tiny bit more than the EH64). EH65 is the 22 HP version and EH72 is the 25 HP carb version with the EH72FI being the 28 HP fuel injected version. All of these engines have same block and same physical dimensions -- so presumably that Gravely muffler would fit on any.

For me, the thought of going Honda or Kohler Command Pro really rests on the fact you have to fabricate or have fabricated your own exhaust system. Those only have 3 yr warranty IIRC. And regardless, NONE will work as far as I understand it -- with the existing engine adapter that is on my 8179G with the KT17II. So no matter what I do, I have to have something made that will work.

I did talk at length with Bruce Guthrie (Gravelymay) about this. If I understood him right, he's got a "filler plate" that works for the Honda, along with a seal. I was originally of the understanding from guys here on this forum that he had or could make an adapter plate for the Robin -- I don't believe he's done so and I don't know if that is possible. Bruce knows way more about this than me. He said he had a different adapter with plate that would work and ultimately, if that is the case, I don't care if it is 2 pieces as long as it would do the job right. He told me he just sold one for a Robin re-power and was looking forward to hearing from the guy how it worked out. If Bruce gets confirmation that all went well, I am pretty sure I'll move in this direction.

I believe many of the other parts (like throttle & choke cable and such) are still available through Gravely, although I am guessing that's not such a big deal.

BTW, is there anyone out there with a Robin engine adapter that either wants to sell it -- or has had it scanned and an engineering drawing created so that it can be milled by someone with the right equipment? If so, send me a PM because I would sure be interested. Hopefully all of this will come together so that in Spring I can get on with a re-power.

 

[Steveamy40342]

 

[IL_Gravely8179G]

Hi Steveamy40342!
That was fast -- I tried to send you a PM but the system said I couldn't because you have to free up space (too many other PM's I guess).

If you want to PM me with an email, we can take this conversation off-line -- am VERY interested (obviously).

Thanks!

 

[maxmetal]

max, I'll have to check on the 1st situation -- spent all day trying to do the final clean-up, not quite done yet. 2nd situation, yes, I think that's pretty accurate, if I bring it down to idle from full up, it smokes a ton -- then if I go back up to full, get a big cloud of blue smoke which pretty much goes away once revs are up all the way. At full throttle, i notice no smoke whatsoever.

One thing I did today was tried to leave it in gear, full throttle but lower gear so I wouldn't have the engage/disengage/forward/reverse where it seems putting the load on the engine causes a lot of smoking.

max, if I understand the Kohler service manual, I've got to pull the flywheel in order to get the pistons out -- is this a correct assumption? also wondering if I need to do same to replace valves/valve guides?

It sounds like intake seals/guides.

I would imagine that you can get the intake valves out without pulling the flywheel, but I am not sure.

The low delta-vee approach might be to refurb the intake guides and put her back together. That might be all it needs.

 

[Steveamy40342]

If you want to PM me with an email, we can take this conversation off-line -- am VERY interested (obviously).



Thanks!

Done!

 

[IL_Gravely8179G]

Done!

Steve, don't know if you've checked your personal email but I mailed the check yesterday and await the adapter's arrival -- thanks!

On another topic as I prepare to make this engine change -- I don't intend (nor do I think it necessary) to put in all new wiring.

My 8179G has the mechanical hydraulic pump (run off the trans), it has the seat switch, time delay and F-R interlock switch. It has no oil gauge or light and the Kohler was points/condenser, not electronic ignition.

I was looking at the wiring diagram for the 20G w/the Robin and it looks like it has a 6 post ignition switch -- mine is 5 post. Do I need to change the switch?

Also, I see the following to/from the engine: Oil Pressure (don't have now), Fuel Solenoid (don't have now, mechanical pump on the Kohler), Regulator (same), Magneto Kill (don't have now) and of course Starter (same) and starter solenoid (same). I'm assuming I should not have to do anything or change anything related to the relay, seat switch, interlocks (F/R and PTO) and time delay. Just need to have an idea of what's ahead re the wiring needed for the above. Would seem simple but I just don't have the experience to know what to do.

Thanks!

Can someone give me some guidance on this?

 

[chevy19533]

Steve, don't know if you've checked your personal email but I mailed the check yesterday and await the adapter's arrival -- thanks!

On another topic as I prepare to make this engine change -- I don't intend (nor do I think it necessary) to put in all new wiring.

My 8179G has the mechanical hydraulic pump (run off the trans), it has the seat switch, time delay and F-R interlock switch. It has no oil gauge or light and the Kohler was points/condenser, not electronic ignition.

I was looking at the wiring diagram for the 20G w/the Robin and it looks like it has a 6 post ignition switch -- mine is 5 post. Do I need to change the switch?

Also, I see the following to/from the engine: Oil Pressure (don't have now), Fuel Solenoid (don't have now, mechanical pump on the Kohler), Regulator (same), Magneto Kill (don't have now) and of course Starter (same) and starter solenoid (same). I'm assuming I should not have to do anything or change anything related to the relay, seat switch, interlocks (F/R and PTO) and time delay. Just need to have an idea of what's ahead re the wiring needed for the above. Would seem simple but I just don't have the experience to know what to do.

Thanks!

Can someone give me some guidance on this?

Here are some pictures that should help from my robin 20g. Let me know if you need any more

 

[gravelymay]

I don't believe you will need a new switch.?
The big cable to the starter only gets power when the switch is turned to start.
So you can run a small wire to the big cable connection on the starter and to the small clip to the starter solenoid.

The wire that supplies 12 volt to power to the coil now.
Can be used supply 12 volt to the fuel shut off valve.
When you turn the power off the engine will die.

Now the wire that now is hooked to the voltage reg .
Can be hooked to the new voltage reg same wire.

This way you don't bother the wiring or safety circuits ..

some engines you need to ground some wires for the engine to run.

Thanks Bruce g.
423 716 4611

 

[IL_Gravely8179G]

I don't believe you will need a new switch.?
The big cable to the starter only gets power when the switch is turned to start.
So you can run a small wire to the big cable connection on the starter and to the small clip to the starter solenoid.

The wire that supplies 12 volt to power to the coil now.
Can be used supply 12 volt to the fuel shut off valve.
When you turn the power off the engine will die.

Now the wire that now is hooked to the voltage reg .
Can be hooked to the new voltage reg same wire.

This way you don't bother the wiring or safety circuits ..

some engines you need to ground some wires for the engine to run.

Thanks Bruce g.
423 716 4611

Bruce, thank you, that is very helpful. I have wiring diagrams for both -- and as I mentioned to you on the phone, unless that Kohler conks out during the winter I am planning a spring changeover to the Robin. I am doing my best to have as much figured out before then (including parts) so I can get this done with little time lost. I figure I'll have a good 2-4 weeks once Spring arrives -- have to let the ground dry out enough before I can ride the Gravely on the lawns. Once I have a chance, I'll go back to the wiring diagrams (and also look at my Gravely) to make sure I am 100% on what you told me to do above.

Hope you had a great Thanksgiving!

 

[IL_Gravely8179G]

It's been a while since I've posted -- a quick update along with some questions as I continue to "line things up" for a spring-time repower. I haven't fully decided what to do with the Kohler KT17II; at the moment, I am thinking of selling it intact but realize that parting it out might yield far more $$$ towards my looming repower.

I've ordered from Richard's these Gravely parts:
Robin-Subaru muffler
Seal
Key
Interior Snap/Retaining Ring

Along with the adapter, bolts, washers/thrust bearing I acquired, I am close to having all of the parts I know about needing. I tried to order the throttle and choke cable from Richard's -- the throttle cable wasn't available and turns out that even though Gravely thinks they have the choke cable in their warehouse, they don't! Jamie tried several times to order and each time they sent the wrong part. We gave up. I'll see if the existing cables will work -- if not, I will have to make some new ones but don't know at the moment.

I plan to purchase the engine in the next few weeks -- one big advantage I see to the Robin is that there is now a 5 yr warranty on it.

Here's where I'm getting stumped -- the existing Kohler is a points/condenser engine while the R-S is electronic ignition. I can post the wiring diagrams of the 2 engines. I came across this thread:
[URL="http//www.mytractorforum.com/24-gravely/220579-rewire-motor-different-tractor.html

Similar issue of moving from an old-style engine to new --

The R-S wiring has connection for oil warning (no such lead/wiring on the Kohler) and of course the whole points vs electronic ignition.

If I post images of the 2 wiring diagrams, would someone that knows how to do this be able to help and tell me what I would need to do. Funny enough, I feel pretty confident when it comes to the mechanical aspects of this repower but I am truly kindergarten level when it comes to the wiring/electrical side of things.

I'm doing my best to learn as I go so I can gain some much-needed knowledge. I'm sorry for my ignorance.

 

[Gravely16G]

I'll be following this. I'm thinking if I ever repowered I'd want the robin 28 hp but would keep the old engine and block & Either work on rebuilding it or keep it for parts

 

[IL_Gravely8179G]

I know it's been a while since I posted and wanted to get back to an update along with a list of questions to ask the experienced guys here.

I've been able to keep the Kohler KT17II "alive" throughout winter and into spring making sure to change oil often and also switched to 15w-50 Mobil 1 synthetic which really does reduce the oil consumption. I'm burning about 12-16 oz for every 60-90 min of run-time so I check it every hour and add as-needed.

Today, 2 things happened:
1. went to the Robin-Subaru US HQ in Lake Zurich, IL (not far from home) and picked up a new Gravely-spec engine! For anyone interested, the orginal part # was EH650DB7510, superceded by part #EH650DB7520. It is a 650cc engine (about 22.4 hp) but sold as 20.5 (don't know yet if that has to do with how the engine RPM's are set from factory or not).

2. it's been raining like mad here the last several days and it dried out enough to cut my Dad's grass (1 1/3 acre) and mine -- except I didn't get mine finished because as I was cutting, the tractor literally just stopped running. No backfires, no coughing 1st, no nothing. One minute running fine, next second totally dead. Would crank but not re-start. I am hoping to diagnose and fix -- mainly because I want to get 1 good dry grass cut in before I attempt this transplant. Am thinking it is one of the safety switches gone bad or possibly points way out of adjustment.

A quick shout-out to the Robin-Subaru folks in Lake Zurich. They were great. I was able to call and find out that they had 3 Gravely-spec engines in inventory. They referred me to one of their big distributors with a personal contact, who normally would not sell direct to a consumer (they typically sell to dealers/shops) -- Oscar-Wilson in MO. They were terrific and were able to order the engine, I paid via CC and picked it up in person this morning (came in a small enough box to load into the back of my SUV, about 22x24x23.

I will post pictures as I go through this process.

The Gravely part # for the 20G w/Robin is Model 987072.
Unfortunately, the wire colors on the Robin engine don't match exactly the wiring diagram. There is only a 4 wire harness to worry about with the following colors:
Green/white stripe
Red
Black/white stripe
Yellow

I haven't traced everything but "think" the red goes to the regulator, the black/white s/b the magneto kill, the yellow sb fuel solenoid and green/white s/b oil pressure light (which my 8179G does not have). It looks to be a pretty standard Packard 56 4 terminal female connector (2+2).

I already tried the engine adapter I bought from Steveamy (thanks again) and it bolts right up perfect. I don't yet know how the throttle/choke will work out but hope it's not too big a deal to route/connect.

Chevy1953 posted a few pics of his real 20G Robin powered Gravely and he has the 5 terminal switch (just like my 8179G). Any thoughts on wiring?

Other question that is really pressing -- a few weeks ago I tried to thoroughly clean the engine/trans so I could get a better look at wiring, routing etc. It appears that the trans is leaking oil right at the bottom of the case where the halves connect. I have never gotten this deep to have to pull the wheel, axle, etc to split open the case -- wondering if folks here have thoughts on this? Do you think a gasket replacement will work or do you think that after 30 years the various seals all need to be replaced??? And then if I am opening the case and pulling the engine anyway, what about the PTO clutch?

As I type this, it sounds like I am in for several intense days of work along with having to order a bunch of parts that I don't currently have. Wonder what I am looking at for all of this?

One last note for everyone as to why I'm bothering -- I do need a machine that can cut grass and blow snow (currently do 3 big driveways in winter: mine which is 140 ft long and 40ft wide by the garage; my neighbor's which is over 200 ft long with a turnaround circle and parking area; my Dad's, he's a block away and I drive on the street to him, he's got about 50 ft in front of his garage and a good 100 ft of driveway length).

Because of the above, I ruled out getting a commercial zero turn for the lawn because I still need a big enough machine for winter. I started looking at the Deere x738, which is 4wd/4ws, 25hp water cooled. The machine alone is over $13K. Started reading reviews and found a guy that had needs like me, had 60" deck (which he proceeded to say cut his grass like crap), blower and cab. For a grand total of almost $25,000!!!!! He said in winter he got 3" of wet snow and in 45 min had to stop 6 times to clear the chute because it was jammed. And the impeller was . . . . plastic. So after reading enough of those reviews, I thought why would I spend that kind of coin (not that I would) only to be SUPER unhappy.

The Robin-Subaru cost me about $1,300. I know I've got some other $ to put into the Gravely but when I'm done, it will still outlast and work better than pretty much anything I could get for a reasonable cost.

Sorry for the long-winded post. Hoping to hear from some of the guys here that have been through this before and can guide me with wiring properly and whether I should just bite the bullet and dig into the trans/PTO as well.

Thanks!

 

[Canary Al]

This will be great fun to watch.

As for deciding to rebuild your Gravely? Obviously the better choice given your needs.

Good for you it has made it through the Winter and Spring.

 

[IL_Gravely8179G]

I've been doing more reading, I believe I have a 5 pin switch
a Stens 430-249/Gravely 019223, pins on it are:
B - Battery
A - Accessory
R - Regulator
S - Starter/Solenoid
I - Ignition


Because I'm moving from a coil ignition to magneto, can I swap out that 5 pin switch for this one?:
Stens 430-070 (crosses over to:GRAVELY 044767)
B - Battery
A - Accessory
R - Regulator
S - Starter Solenoid
M - Magneto

In another thread, I found that the M terminal grounds to the case when in the off position. If so, I would think this would make my wiring confusion much easier to figure out. I'd simply have to move/make sure all wires going to each of the B, A, R & S terminals are in the same place and then run the magneto wire direct back the the M terminal. For some reason, I'm sure I'm missing something.

????:dunno:

 

[IL_Gravely8179G]

This will be great fun to watch.

As for deciding to rebuild your Gravely? Obviously the better choice given your needs.

Good for you it has made it through the Winter and Spring.

Al, thanks for your optimism, I'm going to need it!

Quick update of what I've found so far on wiring -- nothing (and I mean nothing) matches up to what Gravely shows for the Robin-powered 20G nor even what Robin-Subaru shows in their database!

Gravely shows a 6 pin switch but they apparently used a 5 pin switch.

Called Robin-Subaru and talked to Engineering. They looked up specs, and believe it or not, what THEY show in their diagram and what I physically traced on the new engine does NOT match up.

The 4 wire connector out of the engine has the following:

Red - traced back to the carb/fuel solenoid

Green - traced back to the middle position of the regulator (3 wires there, 2 outside wires are black, middle wire is green going to the connector)

Yellow - connected to a small gray wire which appears to go back to oil sensor

Black w/white stripe - was not able to follow this very far, connected to a thinner ga black wire but I didn't want to remove all of the engine shrouding to see where this went.

I've sent an email to the Robin-Subaru guy (even he was surprised when talking with him today when I told him the 4 wires colors I had -- because they did not match what he showed in his spec database for the engine, which I have confirmed IS the Gravely spec engine. He also showed btw a 5 pin magneto style switch being used).

Anyone feel confident based on what I posted as to what I should connect to what on my 8179G?

Again, also thinking I should swap out the existing 5 pin ignition/coil switch for the 5 pin (Sten 430-070/Gravely 044767) magneto switch. :dunno::dunno::dunno:

 

[lt4xtreme]

I believe the 6 pin ignition switch is the same as the 5 pin grounding to case but instead of grounding to case it grounds to the extra 6th pin. I have one of those switches so I'll look at it tomorrow. I do know the same 5 pin connector fits it and the 6th pin is off to the side and uses a separate connector. I think the 6 pin switch was used to provide a more reliable grounding circuit instead of relying on the housing grounding to the dash and the dash grounding to the frame and so forth.