A rider ...

[pd]

I ruffed in the exhaust spacer / insulator this evening . It's a bit crud yet , but it seems like it'll do . I'll give it a spit and polish tomorrow .
It was too dark for a pic when I came in for the night . I'll have to post something tomorrow .

Pete .

[pd]

I didn't get to 'finishing' the insulator today , but I did get a little father before the neighbors came by to visit .

Just to give you a bit of history , this is what I started with :



These are what I removed from ^ :



To get what I have now , fit to the exhaust port with the manifold in place :



It still needs a finishing touch and longer mounting studs , but you should get the idea .

Hopefully it will accomplish it's intent .

Pete .

[carryall]

I never realized how large the exhaust port is on a servi motor in relation to the cylinders size.  Another "thought" about your seizing I had was...It sounds counter intuitive but, too high a ratio of oil in the pre-mix fuel will also cause an engine to run too lean, and run hot.   

[pd]

You're up kinda early .

 I've had seizures while running Opti-2 @ 50>1 as well as Lucas @ about 30>1 .

It's been a bit frustrating , but , it ran longer than 10 minutes when it came from the factory . It'll run longer than 10 minutes , again , someday . I'll just keep trying .

Pete .

[carryall]

Ya, I figured you'd have thought of that.  That would have been too easy, right?  Like you were eluding to, the different expansion co-efficients of the cylinder and your after-market piston and/or rings would need all the fore mentioned to be checked at their known operating temps to really narrow down the culprit.   Speaking of "shot in the dark"... Getting up early lately because I want to take the bike and night-vision binoculars out after midnight couple times this week for the Perseid Meteor shower,  so I figured I'd get up early and/or take a nap and do it, weather/cloud cover permitting.  Supposed too be twice normal rate per hour.

[pd]

The after market piston may be less than OEM , but

I heard that early Friday morning will be peak for the shower . I might be up early enough the catch some of the action .

Pete .

[Ricks]

Pete, what is the point of this?  I think you are trying to solve a problem that doesn't exist.  Simplex spent good money engineering and developing their engine over a 25 year period.  I would suggest taking the motor completely apart, measuring all the components and build it back to specs.  There is no reason your motor will not run as good as the hundreds of Simplex motors out there.  There has got to be a reason you are having these problems, the answer is to find it.

[pd]

"There is no reason your motor will not run as good as the hundreds of Simplex motors out there. "

That's exactly what I've been telling myself and I've been trying to find the answer as to why it doesn't for the last 3 years , Rick .

New bearings , ignition coil , seal , connecting rod , piston , pin and rings ( twice ) and a new carburetor . I sealed the holes in the intake throat twice , just to be sure . I insured there was no possibility for a leak at the seal bushing .
Base gaskets and compression plate gaskets .

I did a pressure test . Something I've never seen done here before .

The point of this exhaust insulator is to try eliminating an exhaust leak at the cylinder . The manifold is/was warped for a second time ( visibly so ) . It's likely been warped and I hadn't noticed .

I have to tell you that I'm having a hard time with this motor like I've never hard with any other in my life . That's an awful lot of motors , both 2 and 4 stroke . My other bikes ( both 2 and 4 strokes ) are also antiques , but I have them running as good or better than new . But , not my '57 .

Have I thrown in the towel ?

Pete .

[carryall]

   I, (along with others I'm sure) have experienced the "mechanical mystery tour" before PD!  (wasn't that a Beatles album?)  All you can do is try finding the "obvious", and then speculate at the what other possibilities it could be sometimes... Understandably,  It can really try your patience.  Regardless, Hope ya get it figured out.

[pd]

LOL . Yeah , The Beatles ... Magical           Ku Ku Kachoo 

Hopefully I can pull off a bit of magic and get this motor running .

Pete .

[pd]

Question :

Has anyone ever removed the OEM exhaust studs ?

I put a vise-grip on a couple and could not budge them . I thought that I had them out before , but

Pete .

[ndian22]

Pete if you can get two two nuts on the stud & tighten them together, then using a small wrench on the nut closest to the motor ease the stud out. Be careful or you will snap the stud off, which often happens even when you're careful. If you're unsuccessful with the afore mentioned process use a propane torch (the blue wrench) to heat the stud while applying pressure with the wrench as outlined first.  I've probably used this technique a thousand times mostly with success but I've snapped some off as well. The small diameter studs of unknown metallurgic quality are the worst & I'd say that's what you're dealing with. Be patient and if moderate force doesn't budge it then a good penetrating oil applied a couple of times a day over several weeks will typically do the trick, again using the same techniques I've outlined. 

Rick C. 

[Ricks]

I use the same method as Rick C, except if I have to go to the heat wrench, I heat up the aluminum around the stud and not the stud itself.  When I was a young man, I worked in an exhaust shop for a year, and this is how we removed studs from exhaust manifolds, and we rarely broke one.

[carryall]

   I have done it "both ways" (stud and engine case)  Worst case scenario, if it still wont budge (or it broke!) I have "tack welded" a nut to the end of the stud and used an electric impact driver to work it back out. 

[Ricks]

   I have done it "both ways" (stud and engine case)  Worst case scenario, if it still wont budge (or it broke!) I have "tack welded" a nut to the end of the stud and used an electric impact driver to work it back out. 

Worst case scenario is drill it out.  If it snaps, I would drill a small hole right in the center of the stud.  Then step the drill size up slowly, to the point most of the stud is gone, like 75%,  then try an EZ-out.  Be careful not to snap the EZ-out, as they are darn near impossible to drill.