New simplex owner

[Mo in Mo]

Not sure when it was printed its a copy of a original. I got it from someone else who has a 37.

The bearings and seals are replaced in the housing. The bearing at the base of the crankshaft is gonna take some motivation!!! The outer housing and the bearings fell off the shaft, when I removed it but the inner part is not moving. I guess after 80 years its just a little snug. The flywheel had slight resistance I'm guessing this is why. I have sprayed it with some penetrating fluid and gonna wait till tomorrow to see if I can get it off. The wife was slightly angry that the house smelled after baking the engine. I thought the smell would be gone after 4 hours while she was gone, I was wrong!!!

[Ricks]

A Tip:  use your gas grill outside, if you have one.

[kartjockey]

Mo, once you have all of your components cleaned up for inspection you will want to pay close attention to your rotary valve running clearance.   Critical to how easy your engine will start.  Check for wear the area in the block it spins in and the O.D. of the rotary valve.

[Mo in Mo]

When you guys put in new bearings, do you pack them with grease. I know you would on normal uses, was unsure in this application.

[Mo in Mo]

So I have been struggling for the last 2 weeks to start the bike. I have had some carb issues (float, needle, jets) and other things creep up (it is 80 years old so its expected). I believe that is all cleared up finally, but the bike will not start. I have tried numerous things. I get a spark when the plug is out of the cylinder. I have then tried to put a little starter fluid in the motor and then try to start it and it wont even fire. I'm next going to check the compression with a gauge but would should the ideal reading be for the bike?

The points may be a little off but since I'm getting a spark they have to be at least opening and closing. When I look through the inspection port they do open and close as designed and I used a feeler gauge to adjust, so if they are off it would only be by a slight bit. Should it be this hard to start a bike that is suppose to be "Simple"

 

[pd]

I've heard that some have ran on compression as low as 60 pounds . I can't imagine that they would have much , if any , power . The lowest that I've had my motor running is about 80 pounds .

What color is the spark ? Weak reddish or strong whitish blue ?

I suppose it's possible that the points might be a bit dirty . I use a clean dollar bill drawn between closed points to insure clean .

It's also possible that the spark plug is bad and will fire outside the motor , but will get 'blown out' ( so to speak ) when in the compression chamber . In other words , the spark is too weak to do any good or nonexistent . That's not real common these days , but definitely happens . A new plug is in order .

Those are just a few things that might keep the motor from running .

Pete .

[Ricks]

These bikes will flood very easily, and then will be impossible to start.  To check for a flooding condition, loosen the compression plate cover.  If fuel runs out, you are flooded.

What carburetor are you using?  What are the settings on the needle valves? Is the carburetor rebuilt?

We need some more information to get you pointed in the right direction.

[Mo in Mo]

The carb is a Tilloston MS 93B. I did rebuild it with the kit from Wayne. The first problem I had was jet was plugged, then the float wasn't adjusted properly (Flooding). Then the needle wouldnt move, since it was new it fit too tight. I have since fixed all of that. It is not flooding now. I have the manual and it said to adjust 1 1/2 turns out on the lean knob and same on the jet. It said after it was running you could then fine tune it.

I have a brand new "old" spark plug. I found someone who has over 10,000 old spark plugs, he is a "spark plug expert," I didn't know one existed but he knew everything about spark plugs.

The spark was blue. I cleaned the points with a business card.

I have been trying to start it in the garage, not running down the street. I have a drill that I have attached to the flywheel nut and spinning it that way. I figured it would be easier to get the carb adjusted that way. Since mine has no clutch just thought I would have better luck getting it fine tuned that way. I could be way off on that approach.

Sorry I didn't include that on the last post. Any other advice on what might be the problem. I have asked a bunch of guys at work and we are all kind of scratching our heads together, which is like one normal person.

[Ricks]

Did you check the rotary valve clearance?  What is it? 

Did you bore the cylinder and put a new piston in it?  If not, is the cylinder round?  What is the ring gap? 

Take a compression reading and let us know what you get.

[pd]

If the spark is bluish , the the points and coil should be good .

A compression test could be telling .

Pete .

[Bob53]

Hi Lester, Make sure and check the rotary valve clearance. Bob Kerr here in OK says this one of the problems of the simplex engines. They don't make enough suction to suck gas into the cylinder to run correctly. If this has too much clearance or wear it will make them hard to start and won't develop the power it should. What part of MO are you from. I'm about 40 miles northeast of Tulsa, OK. I've got a few pictures of the early direct drive bikes. Counting yours I know of 5. I have a frame, front end, handlebars and gooseneck, tank, headlight, generator, wheels, and seat. Long way to go. Probably never find an engine. But I'll keep looking. Could you post or send me some detailed pictures of your front and rear brake setups so I'll know what to look for. Thanks, Bob

[Mo in Mo]

How would I check the valve clearance and what should it be? Could I use a feeler gauge like you would for the points?

Bob I sent you some pics of the front and rear brakes, just let me know if you need any further. I live in the middle of the state just outside Jeff City.

I tried to check the compression,but I'm gonna have to attach the belt and go down the street, when the weather gets better. I only got a reading of 20 psi. So I think my drill is not powerful enough. Hopefully that has been the problem all along, at least wishful thinking!!

[Ricks]

How would I check the valve clearance and what should it be? Could I use a feeler gauge like you would for the points?



Bob I sent you some pics of the front and rear brakes, just let me know if you need any further. I live in the middle of the state just outside Jeff City.

I tried to check the compression,but I'm gonna have to attach the belt and go down the street, when the weather gets better. I only got a reading of 20 psi. So I think my drill is not powerful enough. Hopefully that has been the problem all along, at least wishful thinking!!

I use a telescoping bore gauge and micrometer to measure both the bore and the rotator valve.

Like I asked earlier, did you measure the ring gap?  Did you check for the cylinder out of round?  Did you have it bored and a new piston installed?  Need more info.

[Mo in Mo]

The gap is .05 on the piston rings when in the cylinder, according to the manual it should be .04 to .06. When out of the cylinder its .25

I didn't have it bored or a new piston installed, it isn't out of round.

The rotator valve clearance from the housing is .02

I think this is all within range, not sure on the rotator clearance as the manual doesn't say. I will put back together and try running with it to get an accurate pressure reading. Since I only got 20 psi on the tab with the drill method. While the drill seemed like a good idea, I don't think its going fast enough to get a good reading. Which could also mean not pulling the fuel.

[Ricks]

The gap is .05 on the piston rings when in the cylinder, according to the manual it should be .04 to .06. When out of the cylinder its .25

I didn't have it bored or a new piston installed, it isn't out of round.

The rotator valve clearance from the housing is .02

I think this is all within range, not sure on the rotator clearance as the manual doesn't say. I will put back together and try running with it to get an accurate pressure reading. Since I only got 20 psi on the tab with the drill method. While the drill seemed like a good idea, I don't think its going fast enough to get a good reading. Which could also mean not pulling the fuel.

Are these numbers correct, or did you leave out a zero?  As in .005 ring gap, and .002 rotary valve clearance?  If you left out a number, those clearances are excellent!  If not, there is no way it will ever run.

The drill method should provide plenty of cranking speed to start or take a compression reading.  This is how many people test these engines on a bench.  If you are only getting 20 psi, there is something very wrong.  Just thinking out loud here, but did you put the piston in the correct direction?

How do you know the cylinder is round?  What method did you use to check it?

Did you put new rings in it?  If not, maybe the original has lost its tension.

Did you hone the cylinder?

Don't get discouraged, we will get you pointed in the right direction!