SAE30 16:1 observations

[FreeWheeler]

I have spark which is no big surprise, and mag resistances check ok. There is a cloth coating on the mag windings which looks stained, but it is dry inside and I sealed the wire opening.

Just before it started running with 1/2 power it died out once or twice and restarted but it seems like the trouble started then. It was the day after it quit briefly that I could feel the power just getting slowly worse until it only has 1/2.

 

[FreeWheeler]

Here's a picture of the mag. The resistance checks, but this thing is nasty looking. It was dry when I opened it, but it looks like it got wet at some point. Could this be it?

 

[GearNut]

It does not look much different than the mags in my engines. I think that the brown ugly coating is a lacquer that the factory sprays on them or dunks them into to "seal" them.

 

[FreeWheeler]

GearNut, I think youre right about a coating on the cloth which goes over the windings. The wire is red and where the cloth got soaked with resin, it looks like red rust.

The mag has been ruled out by DAX. I noticed the plug is really wet and I guess that makes sense if it's only firing 1/2 the time. I've tried to read everything I can find on CDI problems. I know it's rare for them to fail, but what else would it be?

 

[Pablo]

CDI's can and do fail.

 

[GearNut]

I agree with Pablo.
CDI's are not bullet proof. They can fail, although when they do it's usually a complete failure; like a wire got disconnected. Do not rule out a partial failure though, stranger things have happened before.

 

[FreeWheeler]

I agree with Pablo.
CDI's are not bullet proof. They can fail, although when they do it's usually a complete failure; like a wire got disconnected. Do not rule out a partial failure though, stranger things have happened before.

DAX sent me a new CDI and I noticed a slight improvement, but it didnt last. I also replaced the plug with a NGK bp6hs. I went to run it today in daylight to see if it really improved, but it only got worse. It started and I was hopeful, but it progressively deteriorated until it wouldnt idle unless the throttle was wide open. Forget about pulling me.

Do you think exhaust is clogged like original guess? Could my float be sunk?

 

[FreeWheeler]

I took the carb apart tonight, removed all the solder from the jet, removed the inlet and checked for gunk. It was still clean as a whistle. I removed the exhaust and it seemed clear.

The only thing I can think is that maybe the little pin that the float spring rotates around was caught in the gasket? When I opened the carb that pin was sticking out on one side and the gasket came off cockeyed. My trouble started after I rejetted. It ran gooder and then I took it apart again and reflowed the solder because I thought I could do a neater job of it. This was when the trouble started. When I did this, I didnt remove the carb from the bike to remove the jet and maybe I did something with the gasket and that pin/bearing since I was working kinda blind.

Is it possible if that bearing was pinched by the gasket, that the float wouldnt be able to shut off the fuel and it would run really really rich?

 

[Dave31]

Are you sure you are putting the retaining clip above the needle? Hmmm, I cannot find any pics but after you install the throttle cable, the needle does not move up in the slide?

The throttle spring in the slide should push down on the retainer, that keeps the needle from moving.

 

[FreeWheeler]

Are you sure you are putting the retaining clip above the needle? Hmmm, I cannot find any pics but after you install the throttle cable, the needle does not move up in the slide?

The throttle spring in the slide should push down on the retainer, that keeps the needle from moving.

Hey Dave31, if youre talking about the barrel slide part, I'm pretty sure that's fine. I'm checked out on adjusting the c-clip which would include getting the throttle pin right.

I dont know what I did to the carb, if anything. I'll test it out tomorrow.

 

[Dave31]

This is what it should look like before you install the spring and cable. So many bikes I have worked on that just dont run or dont run right this is what I find. I was just taking a wild guess....

 

[FreeWheeler]

Yup,thanks, that's how I got it. Wish it were the problem. I realized what Gearnut might have meant by clogged exhaust, clogged in the port not the pipe maybe? I realized this after I hacked my exhaust pipe in two pieces tonight. Now I have to get that welded back. Oh well, maybe I'll have it running tomorrow.

I did one other test earlier and that was to run it without the air cleaner and it ran good enough to haul me. Not fast, but it ran.

 

[FreeWheeler]

I dropped the muffler off at the welder who said get in line, call you in a few days. I removed something which had lots of crud build up in the grids When I blew through the exhaust before taking it apart, it was open but not like after I removed that crudded up thing.

This all refreshed my memory of when the problems started. I had removed the top screw, trying to see if I could get it apart to keep clean. I didnt replace the screw for a few days and kept riding. The top screw holds that cylindrical grid crud catcher. When I removed the pipe yesterday, it made a clanking sound like something inside was loose and it was. This loose part had dropped to the lower end of pipe. I dont know if that was the cause of loss of power, but it isnt in there now and wont ever be a problem.

Here's why I think the crud catcher could be the problem: It is supposed to be at the engine end of the pipe and it had dropped to the bottom. The velocity of the exhaust is much higher at the engine end which means crud builds slower, so it takes a long time before it causes a problem. This thing restricts flow to begin with and if it is near the exit end of the pipe, the slower flow at the exit end will actually encourage crud buildup plus the grid is a bigger obstruction to a slower flow.

We'll see when it gets back from the welder.

 

[GearNut]

The "crud catcher" inside the muffler is a catalytic converter. If yours dropped down inside the muffler it would partially block off the holes in the baffle tube seriously affecting the flow through it. It is usually held in place by a little screw on the side of the muffler, closer to the engine end. If that is the screw that you removed, I bet that was your problem.

 

[FreeWheeler]

The "crud catcher" inside the muffler is a catalytic converter. If yours dropped down inside the muffler it would partially block off the holes in the baffle tube seriously affecting the flow through it. It is usually held in place by a little screw on the side of the muffler, closer to the engine end. If that is the screw that you removed, I bet that was your problem.

The welder called and I picked up the pipe and installed it. It ran better, but it still isnt breathing. The only way it even has enough to pull me down a flat street is with the air cleaner removed. On top of that, on one trial I forgot to turn on the fuel and when the bowl ran out it ran great, so that points to running way rich. I have no clue why it is so rich.

 

[FreeWheeler]

I took the pipe off again and sprayed a can of WD-40 down it and shook it up. When I pulled my thumb off the outlet, it was totally black gunk running out. I also sprayed the air cleaner and squeezed out all the oil. It looks and feels like new. I'm not too hopeful, but wont know until I try it again. If all this doesnt work, then I need to look at the carb or the mag wires again I guess.

 

[FreeWheeler]

I got a glimmer of hope today, but not for long. It starts right up, always has, but no power to pull me. I warmed it up and started going down the street when I felt some power come back, but it was intermittent. It started coughing and backfiring, pop, whoof, bwaaaan, stall, pop, whoof, bwaaaannn. It had enough to pull me up a small hill and I thought something cleared and then it was back to no power.

 

[GearNut]

I'm thinking (agreeing with you) that you have more of a carburetor problem than a flow restriction problem. The business end of the spark plug is still black, yes?

 

[FreeWheeler]

Plug still looks very rich and wet. I have the c-clip on the last notch up and ran it without the air cleaner. It acted like it was starving at times and then rich, so I blew out the petcock. I also adjusted the tangs on the float valve, more down, and float sits level with jet, will shut off sooner.

In another thread, the possibility that the slide guide pin got sucked through the engine since carb barrel doesnt have one now, was mentioned. This NT carb looks almost like it came without slide guide, very clean barrel. I'd think if it broke off, it would look rough not so machined off and recessed. There are marks from the slide going up and down in the same spot where the guide would be, which says it might have had a slide guide at one point. Could have been the first engine that sucked it up. Compression is good and strong.

 

[FreeWheeler]

Got it running good again!!!

This thread should be closed after this last "observation". While trying to troubleshoot why it ran like crap, I switched back to 24:1 synthetic homelite. I went to the opti website and read the explanation of that product vs. various generations of lubricating oils. This bike started with the generation 2 synthetic and then I switched to 1920 technology in the non-detergent no additive SAE30 and it's now back on synthetic. For all I know, the peaks and valleys of this motor have been rearranged in ways that shouldnt happen and I got lucky in the end. I wont be using generation 1, 1920 technology, unless it is life or death.

The initial boost in performance switching to 16:1 was there, but it didnt last and there have been major advances in lubrication and metallurgy since 1920.

I'm considering opti2 to put the "final polish" on my engine, but that is a new discussion.