Rancher 55 Top End Rebuild Without Base Gasket?

[jimbo2032]

Hey folks, I have a 55 rancher mfg'd in '00. The last time I used it I noticed it had almost no grunt to it while cutting even though it sounded great while WOT in the air. After attempting to tune the gremlins out I decided to test check the compression and found that I couldn't even get the saw to hit 90 psi.

So I got one of those meteor cylinder kits off ebay with the open/closed/hybrid port that someone posted here a while back. What I didn't get was the base gasket. Would I be okay to put the saw together without this? What kind of sealer should I pick up to use there instead?

-Jimbo

 

[dougand3]

I use Permatex Motoseal from any auto parts store in a base gasket delete rebuild. Hondabond and Yamabond have good reviews. IIRC, you don't want squish under .020". I know FarmerTec/Huztl top ends have a big squish, so base gasket delete is fine. Don't know about Meteor.

 

[71dart]

The 55 OEM cylinders are usually fine to leave the base gasket off, BUT, I always check squish. Especially with an aftermarket kit. Also that way you know where your squish is set.

 

[jimbo2032]

Well, I learned something today. I'd never heard the term 'squish' before, but it was in fact the measurement that I was concerned with.

Is this a proper way to check for squish?

 

[71dart]

Since you'll have the cylinder off anyway, you can install the new piston on the rod and before you put the piston rings on, set four 1/2" pieces of solder attached with a little dab of grease to the top of the piston (2 parallel to the piston wrist pin and 2 perpendicular to the pin). Be sure they're placed at the very edge of the piston. Then slip the cylinder on and bolt it down. Roll the engine over with the flywheel back and forth to mash the solder then pull the cylinder and use calipers to measure the mashed solder. That's your squish. Sometimes there's a little variation between the four but just use the tightest one. Also it helps to have a few different thicknesses of solder and start with the thinest.

 

[idiotwithasaw]

Can you post a pic of your original cylinder. Maybe it could be cleaned up?

 

[Warped5]

Since you'll have the cylinder off anyway, you can install the new piston on the rod and before you put the piston rings on, set four 1/2" pieces of solder attached with a little dab of grease to the top of the piston (2 parallel to the piston wrist pin and 2 perpendicular to the pin). Be sure they're placed at the very edge of the piston. Then slip the cylinder on and bolt it down. Roll the engine over with the flywheel back and forth to mash the solder then pull the cylinder and use calipers to measure the mashed solder. That's your squish. Sometimes there's a little variation between the four but just use the tightest one. Also it helps to have a few different thicknesses of solder and start with the thinest.

One small point of clarification ... when you use your calipers to measure the thickness of the solder, use the area of the caliper jaws out near the tip where they are thinner.

 

[jughead500]

this is .032 solder from auto zone.


i usually twist two pieces together for 4 spots on the piston.when its fully crushed both pieces make a nice larger surface to measure with calipers.

 

[jimbo2032]

I've got a couple of pounds of solder lying around from my last job. I could find the permatex motoseal at Napa, but they did have permatex no. 2 non hardening so I picked some up.

Here are the pictures of the cylinder and piston, they are pretty galled up with deep scratches.


I also sprayed everything down with some Zep purple degreaser, and then rinsed well with hose water and then alcohol to dry everything up. I am planning on just using 2-cyle oil to lube the bearings and reassembly. Is that okay or should I get a specific lube?

 

[Warped5]

2-cycle oil is just fine.

 

[71dart]

It's hard to say from the pic but that cylinder may clean up.
I don't know about permatex no.2. Is it fuel resistant?
2 cycle oil is fine for reassembly. Now's a good time to replace the rubber seal that the impulse tube slips into on the cylinder and be gentle on the carb screws as the plastic they screw into likes to strip.

 

[idiotwithasaw]

I would try and clean it up, hard to tell sometimes if it's a score or transfer unless you have cleaned it out. You don't have anything to lose, you already have another cylinder. Clean it up, and post an after pic.

 

[jughead500]

i think that the permatex no2 is the black goop and isnt fuel resistant

 

[jimbo2032]

I cleaned up the cylinder with some degreaser to get the carbon out, but I can't tell much more than before. What would be the best way to clean it up? I don't have a dremel, only a drill with a wire brush. Would a chemical treatment do the trick?

On a side note about chemicals, be careful with that Purple Zep Industrial Degreaser. I didn't wear gloves while working with it full strength and wasn't particularly careful about keeping it off my hands and had somewhat of a reaction. Skin first was hanging very loose like my grandmothers used to, and then got very tight to the point where it was hard to see the fingerprint ridges on my palm. Very shiny also. A little better this morning, but from what I've read it could have been much worse. Make sure you guys are wearing gloves when working with harsh chemicals.

I got it all back together. Replaced the carb, carb gasket, intake tube, impulse pipe, bulkhead, fuel line, both filters, chain, and the four allen screws I managed to strip while disassembling. I tested compression and it was still at 90 psi, but I figure that will go up after a few hours on the saw as the ring seats itself. Didn't get it running yet though. It seams that a 3 dollar part is going to hold me up for another day. When the engine kept flooding I took a look at the spark plug and noticed that the ceramic insulator was rattling around inside the plug. I guess that means it's time for a new one.

Once I get the plug replaced I will pretty much have a brand new saw!

 

[71dart]

Search for the 2 part video Mastermind did on cleaning up cylinders.
Sorry to hear about your hands!! Gloves are a good idea.
90 psi is low. Are you sure your compression tester is accurate? Did you check your squish numbers?
Also, there's a reason your piston and cylinder are scored and it's a good idea to figure out why they're scored so it doesn't happen to your new p/c.

 

[idiotwithasaw]

90 sounds way too low, the plug may be leaking. Did you use assembly oil.

 

[idiotwithasaw]

Agreed you need to find the cause, you need to vac and pressure check it. Check all your rubber parts for tears or holes.

 

[jimbo2032]

Alrighty then, what a day! I was attempting to take off the clutch assembly to check the crankshaft seals for an air leak, and the darned thing slipped off my workbench and hit the concrete floor, cracking the case at the front near the anti vibration mount... Everything else looks fine.

I have found a replacement used crankcase for about 35 bucks, and a seal kit for another 10. With the full understanding that at this point I could have bought a new saw by now for what I have in parts, how difficult and expensive is this going to be to replace?

 

[mountainlake]

You have to find out why it was running lean, air leak, clogged carb, bad fuel line or just tuned to lean which I think is the cause in a lot of cases from operators who think the extra RPM will make more power when in fact it takes away power. Steve

 

[jimbo2032]

I've already replaced the carb, carb gasket, fuel line, fuel filter, plug, and air filter. If I replace the crankcase I'll replace all the other gaskets at the same time, in addition to the piston and cylinder that I've already replaced. Pretty much I'll have replaced everything except the ignition system after this. It seems every time I touch this thing the complexity goes up an order of magnitude...