Hard starting & cold blooded, What to do?

[Jim Becker]

Since it starts with the throttle closed, it is probably drawing fuel through the idle circuit when it starts. Leads me to think the problem is the main jet or some passage in the main fuel flow path.

On the timing question, I always set timing with the engine at 0 rpm. Impulse should click right on the TDC notch. Once the magneto comes off the impulse coupling, it may already be advanced a little (I think this is the published lag angle, but haven't researched it.). It will continue to advance at higher speeds. If so, and you set the timing for 0 advance running any speed high enough to keep the impulse out, you will probably be giving away some advance.

Distributors are supposed to start advancing at 200 rpm.

[Lurker Carl]

I am not a pro, only an amateur with years of experience. I seldom perform rebuilds for others, mostly just to keep my own motley collection of junk running.

[John Niekamp]

Jim,

I think you are correct on the main jet, the more I think about it the more this makes sense. Man just one small piece of dirt or probably in my case a gooey piece of silicon residue causing all of these problems.

Now that would REALLY make me mad, get ticked off and buy a new replacement carb, just for a piece of forign matter.

To be honest, I wasn't even real sure on the correct process in timming it. (at that time, I didn't even have a book, just what I got from Rudi's server and on here) I just hoped this was correct and figured that since it didn't kick back on the starter for being to far advanced and didn't get hot due to being to far retarded, so I thought it was darn close. I know that several years ago, I fought an old 39 Case tractor getting the mag in time, I just couldn't get it through my THICK hard head about the impulse. I just KNEW the book was wrong, which it wasn't


John

[John Niekamp]

Well just to let everyone know, when I got home form work tonight, I first checked the timing. I was sticking on my reflective tape for the digital tach on the pulley and guess what I found The SECOND mark. It was completely covered with paint, (probably ever since it was new) I saw what appeared to be a burr, done some scraping an dug out the old hard paint. The mark wasn't nearly as deep as the first either and I can now see how I overlooked it.

I also brought home with me from work the shop's analog/mechanical tachometer. With it and my digital tach, they agreed with one another on engine speed. I then ran the engine up to what I found in my book at 375 RPMs and it was on the first mark, ZERO, then at full throttle the second mark came up on the pointer. (by the way, the engine fired right off, with no problems, but again it was in the high 40's)

DOES this sound correct now on the timing? I didn't have to move the distributor any, from when I first timed it last year. I still haven't checked the dwell yet, but I really don't think that is a problem anyhow.

Then I went to the fuel supply, I disconnected the fuel line and had a nice steady flow of gas. So the last thing was left, was the carburetor itself. I took it all part and it was as clean as it could be. I took a piece of my piano wire and ran it in all the passages, NOTHING came out, blew it all out and put it back on, checked the float bowl level and it looked just about the same as Luker Carl's picture did, it started and ran like a top, but It still has the (not as bad) hesitation on acceleration.

My only other guess is, GAS, so tomorrow I will go and get some brand new gas and see what happens. So if the new gas doesn't help any, I am just going to have to live with it and be happy and just make the kids shovel snow in the winter,

I still notice that I have a problem with the touch control, but I'll leave that problem for another day.

Just messing around and according to my tach, I was able to idle the engine down to 104 RPMs, (any slower if would die) thought that was kind of neat. You could almost count the blades on the fan as they went around.

What are these actually suppose to idle at I am not fiinding it in my book or just not seeing it.

John

PS: I still notice that I MIGHT still have a problem with the touch control, but I'll leave that problem or tpoic for another day.

[cublo]

I have read that cleaning jets with wire is a no-no, as the wire (if harder than brass) can damage the jets. Hal in CT

[cublo]

I don't like to admit it, but I have had to use ether to start an engine now and again over the years. One thing I keep in my mind is that if it doesn't fire IMMEDIATELY with the ether, there is almost surely a problem with spark. As a note, ether is a powerful solvent that will wash the oil right off your cylinders, and that can cause real wear problems. In high school I had a '65 GTO with a 389. I gave it too much ether on a cold winter day, and the motor stuck solid, and wouldn't turn even with a good battery and a jump. The next day after the ether had dissipated, it turned over ok. Maybe just a tad smokey after that episode? I can't recall

[John Niekamp]

Well guys it's fixed

Evidently the problem all along was in the fuel. I drained the old gas in a gas can and then the flow bowl and sediment bowl. Then I compared the two gasses in a glass jar, and the old gas was quite a bit darker, where the new was almost clear.

Then the REAL test was when I took a small sample of the old gas in a bottle cap and tried lighting it. it barely light I first tried with a torch striker the sparks wouldn't even ignite the gas. I actually had to take and place flame on it to get it to burn.

NO wonder it didn't run right, I am surprised it ran as well as it did. I swear the gas wasn't older than at most a couple of months and there was no evidence of any moisture.

The Cub started and ran like a sweet dream and there was absolutely no hesitation what so ever. It started no matter where the throttle control lever was place. No choking after the first initial start. Then had to quickly remove the choke.

Now I know I have the peace of mind the timing is correct and everything is nice and clean. I just can't believe gas no older than this would have caused so much troubles. I have other engines that have sit for years and will run on old gas. This is the first for me, maybe they just don't make gas like they use to. Well to some degree this is true, no more lead.

Well I guess this will close this topic and my THANKS TO ALL OF YOU good folks, once again you have saved me. (Now my interest will be on the touch control)


Once again, a very happy Cub owner

John Niekamp

[cublo]

Glad your Cub is running! And it wasn't the Cub's fault. The modern fuels, with MTBE and Ethanol and who knows what else are a sorry substitute for what our Cubs were sipping back in their prime. It goes bad faster, and I know several friends who have had similar problems with fuel right from the pump. Arrgg. Where's Ethyl when you need her? Hal in CT

[danovercash]

Anyone seen the Sta-Bil commercials on tv? Been using it religiously for years.

[John *.?-!.* cub owner]

Never seen the commercials, but I use it the year round. I haul my gas in cans, usually getting 4 or 5 at a time, and I add it to the cans before I fill them.

[John Niekamp]

Anyone seen the Sta-Bil commercials on tv? Been using it religiously for years.

Never thought of ever needing it, UNTIL NOW

Ya know what's even weirder I have a 10 year Honda commercial four stroke lawn mower and today, after all this ordeal. I tought I would see if it would even run after sitting all these months, with old gas in the tank, started on the first pull and didn't miss a lick.......GO FIGURE

I can just barely remember ole Ethyl, but it does bring me to another thought. What about the fuels of today, NOT having the lead in it? Anyone use anything for upper cylinder lubricant? I don't really worry about the slower running engines like the Cubs, but in my old truck I use a additive called "Lead Subistute" I don't know if it helps or not, but I hate to have to tear down a perfectably running engine, just to put in some hardend valve seats, when it only cost a $1.50 a pint, every couple of tanks.

John

[danovercash]

Bet it won't iffin you use gasahol/ethanhol. Honda carbs don't like it, doesn't agree with the o ring material. Honda's start sweet, but I would rather have an IH/Lawnboy self propelled electric start anyday. (See pix on site below)