3410 Problem taxing my capabilities (updated 8/9)

[BrianP]

Okay, so here we are in the month of August and I’m still mowing our 1 acre lot with my dinky 20 inch hand mower. The South Carolina heat (not to mention the humidity), makes this a real test of endurance…or stupidity, I haven’t decided which. To recap; my 3410 had developed a marked refusal to rev much beyond an idle and when I tried I was rewarded with a fusillade of backfires that no amount of carburetor or point adjustments would cure. A new old stock carburetor did absolutely nothing. Like Craig (aka Isleblue65), I’ve been banging my head against this brick wall for over a year! Finally in a last-ditch attempt to get at the root of the problem, I embarked on a full-blown engine rebuild. While the block was being treated to a .020 over-bore and valve guide knurling, I launched into an all out assault on the tins (the shroud, various air deflector bits, even the air cleaner), taking everything down to bare metal. Then I sprayed them with VHT primer, followed by semi-gloss black. I spent most of July prepping the block which I also rattle-canned semi-gloss black. Then came the task of re-assembly. Family complications delayed me so much that I almost forgot how some of the assemblies went together. But I have prevailed and here are a few shots of the completed engine.

Here's another shot...

Fortunately I have a walk-out basement with a garage door where my shop is located. I went out to my equipment shed and shoved my engine-less chassis into my shop and slammed the overhead door on the heat.

Then as I was folding the wires and throttle cable back out of the way to re-install the engine, I stumbled across what I believe to be the source of the problem. Being in my basement, I've always been concerned about fire, so I pulled the gas tank and fuel line out before rolling in. As I inspected things, I suddenly froze.

This is the wire that feeds 12v to my external coil. Holy short circuit Bat Man! :O I had gone to great lengths to run the wire out of harm’s way (behind the gas tank straps), when clearly the opposite was true. Guess I was lucky the short didn’t do more damage. Since I'd run the wire from my 12v source to the switch on the dash the same way, I immediately checked that wire too.

Reveling in my "ah ha" moment I am now pressing forward each night after work, which is quite taxing since I can only work for an hour or so, which is hardly worth getting dirty for. However my grass is getting high and I'm going to fire this thing up this weekend... or else! Here's how far I've progressed tonight:

Since I'm now working in fits and starts, I wanted to let everyone know I hadn't given up. Yeah, the starter's not in yet and I still have lots of wrench spinnin' ahead, but I'm really stoked now! I'll update this thread as soon as I make some more progress. ^ ===================8/8/08=====UPDATE========================= My plan to do some assembly during the week netted me mixed results. Tuesday night I had to work late, so I only had Monday, Wednesday and Thursday nights to work on my 3410. Monday night I re-connected the driveshaft to the engine then moved on to begin tightening the engine mounting bolts. Then I realize I'd forgotten to install the starter belt, and had to take everything apart again. B) Anyhow, this shot shows the coil now mounted and wired up permanently.

Here’s a shot of the starter (including the belt),with the wiring all back in place once again.

In a previous post (regarding external coil wiring), a fellow member mentioned that the line to the switch (and in turn the coil), be fused...you know...uh...just in case there was a short or something. 8 [url]http://www.simpletractors.com/club2/topic.asp?ARCHIVE=true&TOPIC_ID=80667&SearchTerms=coil[/url] as you can probably guess, I wasn’t a big fan of using an inline fuse at the time. Okay, lesson learned. This time, I’m erring on the side of caution and am protecting the circuit with an in-line fuse.

I’ve also run the wiring for the coil along the same path as the factory wiring. I even wire tied the new wiring to the original factory loom.

Hopefully this will put an end to my wiring problems. All that’s left to do is install the gas tank and battery and see what all my hard work has netted me. I have to work Saturday, so I won’t have any more time to play with this further until Sunday. I'm not the fastest worker when it comes to this hobby, but hopefully slow and steady will win the race. ===================8/9/08=====UPDATE========================= I got home from work around 2:30 and jumped right in to my project once more, determined to attempt a start-up. I mounted the muffler (temporarily mounting the hood to check for clearance), and the muffler bracket. By this point it was time to roll it out into my driveway to hook up the fuel tank and battery.

The rubber fuel tank straps broke when I disassembled everything, so in the meantime I’m using a length of plastic coated copper wire as a substitute. I put in a small amount of gas, just enough for a test-firing and maybe a short run-in period. I did this so I wouldn’t have a whole lot to drain back out in case I have to pull the tank again.

I also trimmed all of my wire ties close to prevent interference or damaged flesh.

Even the one way under the dash! ;)

Then I used some split-loom to protect the wire going to the points. I even used an insulated conduit clamp (as suggested by a fellow member), the last one left in my organizer. All-in-all a pretty neat looking installation.

Finally, I filled the crankcase with oil and attempted to fire it up. I flipped the coil switch and turned the key. My reward was the GEN light comming on and nothing else. Not even a solenoid click. Crap! By now it was almost 5pm so I ran inside and grabbed my meter. Sure enough, the battery read only about 9 volts, which I thought might at least do something, but it was no-go. So, back inside once again for my trusty battery charger.

My Dad worked for Delco Battery for 30 years, so I’d become well versed in putting a weak battery on a slow charge overnight rather than try boosting it to start it right away. I was running out of juice myself by this point, so I selected the 2 amp setting and picked up my tools. I checked the meter and she was putting in about 4 amps.

Since I now had fuel in the system, I didn’t want to roll it back into my basement shop (or push it uphill to my garden shed for that matter), so I grabbed some plastic and wrapped things up for the night. :D

Hopefully I’ll get a chance to try cranking it over again Sunday afternoon.

[MPH]

Looking like good progress Brian. Even if you found the real problem later least you now have a brand new rebuilt engine to be running with.^

[goatfarmer]

Fantastic work! dOd My 3410 would also act that way, start chugging, and missing, no power. I ended up replacing the engine with a newer Briggs 11HP, but stuck the cast iron 10HP in the shed. Later I picked up a 2110, that had a blown engine. I put the old 3410 engine in it, and changed the points and condenser, That engine has performed flawlessly for about 6 years now! I guess it likes this tractor better.....

[powerking_one]

Brian, You may want to trim those wire ties(flush cut). I guy I used to work with a HP years ago learned his lesson one day (he used to cut them on an angle leaving a about 1/4"). One day while pulling one of his wire tied cable bundles under the computer room floor, his hand slipped catching on one and put a 3 inch gash across the top of it. He still has the scar. (IMHO) I would also put an insulated wire conduit clamp (or 2) on the blue points wire attaching them to the cylinder shroud screw or other bolt holes in the front of the block. Tom(PK)

[BrianP]

Tom, Thanks for the input. The wire ties will definately be trimmed flush before my test firing. I had a similar experience years ago so I can relate to how sharp they can be. I usually leave the final nipping off for last just in case I have to pull one taught after the final tweaking of the wiring. The insulated wire condut clamp is a good idea also. It's a real bear trying to get this done with all the interruptions I've hade lately, but I'm coming down the home stretch now.