Before I dive in......

Danzig · Post by **Danzig** » Sat Oct 14, 2006 3:43 pm

today....................

Carb pulled off again and recleaned again with 110 psi shop air, nothing was found for dirt, lint, nothing, I even looked at each piece under a very large magnifying glass at the machine shop. Nothing changed guys, except for resetting the carb to this which again isnt correct. The low/mix idle screw is now set out 2 turns. The high speed mix is now 3/4 open. This is the only way I can get the sled to idle without full or partial choke. The sled now however is harder to start. Plugs havent changed color but very minimal, the mix now looks a little richer, plugs are blacker. I hope I am not being too picky. I really dont know how well this sled should run or sound, I have nothing to compare it too.

Heads were pulled also, pistons dont show any signs of heavy carbon deposits. I have to assume the rings are loose because the pistons do show movement when wiggling them inside the cylinder side to side. Both pistons are pit free, no burns from pre ignition. The heads did have some heavy greasy film in the dome area where the spark plug screws in. This was all cleaned off with spray carb cleaner. Heads were then re-installed. I could not check compression today, the I loaned the tester out to a friend the other day. I will check this tomorrow, I really dont think the compression dropped any though. I also looked inside the 4 ports on each cylinder and nothing really looked to me to be all that bad, just some black oily residue.

Danzig · Post by **Danzig** » Sat Oct 14, 2006 8:44 pm

I think I am gonna check on the spark timing between the 2 cylinders and see if I am a bit out of time, I went back into some archive posts and found that possibly what appears to be a carb problem may be related to timing problems.

This is starting to suck really bad.

JDFanPa · Post by **JDFanPa** » Sat Oct 14, 2006 11:31 pm

proper gap on points and proper timing will make a night and day difference as far as starting if they were off...............2 turns on the low side sounds fine.....the 1 1/4 is baseline not written in stone

Danzig · Post by **Danzig** » Sun Oct 15, 2006 4:33 pm

Today the points and timing were checked and set.

The manual calls for a flashlight tester. I used a Fluke meter instead on the 200ohm scale. I found the timing was way off. The points were coming open about .043 advanced. Which mean that after finding top dead center on the cylinder and turning the crank shaft counterclockwise the points did not close till until -.043 on the indicator. Negative -.043 means that I turned the crankshaft counterclockwise. I then also checked point gap resistance at the same time with a Fluke meter or multimeter. With the points open at top dead center, the reading on the Fluke was 1.2 ohms. As soon as the points went to just closed the reading on the meter was .4 and the dial indicator was at -.043. The next step was to check point gap, points are roughly .015 wide open, from what I could tell I am dead on for point gap both cylinders, they didnt give you much room with harmonic balancer being in place, those windows could be just a bit larger. Next step was then to loosen points with the white wire or for #1 cylinder, points were then set to just start to open at -.023 +/- .005 on the indicator. The same was done for cylinder #2.

The white wire leading to the points is for cylinder #1 and the red wire goes to points for cylinder #2.

After more looking into this, the harmonic balancer has slash marks in it, 3 slash marks for #1 cylinder and the same for #2 and the case also has an arrow on it . I also noticed that when the points just start to open that the middle mark on the balancer and the mark on the case line up.

I did have one problem, that when setting #1 cylinder, you are supposed to set the points and then time it by moving the stator, one problem here, the right side bolt on the stator would not come loose, it was stripped out by me today trying to loosen it, the only thing here that I could do for now was to move the points and try to time it that way. Setting #2 cylinder was set the same way, I do know that when setting #2 you do not move the stator.

Now after all this was done, I fired it up and then set the carb again. Now the carb is at 1.75 turns out on the low side and the high speed is at 1.25 turns out.

As far as running, well I do need another set of plugs, I lost total spark on one plug, I did find a used replacement which was a B9ES. The sled is now running one BR9Es and one B9Es.

The next adventure will be to get the harmonic balancer taken off, then get out that stripped bolt that holds the stator on. I will also get another set of points and condensers. Does the sled have the K or D series points?

As far as how it now runs.........I will say its ok, still not satisfied yet. It will Idle at 2600 rpms still, most likely till it runs the tank out of gas still. To start the sled whether its hot or cold the choke must be pulled out and one pull it will fire then die, push the choke all the way in and it will fire up and rev to about 3500rpms and then idle down to the 2600rpms.

Still open for any comments or concerns.........

JDFanPa · Post by **JDFanPa** » Sun Oct 15, 2006 6:40 pm

You have to move the stator to adjust timing moving the points changes the gap only. Your not gonna get the full benifite until you can move the plate and get timing right First you set the point gap right on both points then do the timing. I know your most likely aware of this just letting others know. You were right on with the dial indicator and how you did it just that by only moving the points your timing is probably very close to .043 still and the gap might be off now. Im sure you know how advancing the timing effects starting a car just imagine what .043 is doing when your pulling a rope you will be happily surprised when its set to spec.

what you did with the ohm meter over the tester is cool. I bought a points light thing off ebay and it never works right. What I do is use a strip of thin notebook paper stuck between the points. Rotate the motor counterclockwise to spec then turn the stator until the paper is loose as soon as you see it move/drop lock the screws and your done. I know its not as perfect as the flashlight tester but it is close.

Danzig · Post by **Danzig** » Sun Oct 15, 2006 6:43 pm

The thickness of your average paper is .004. Just an FYI.

A human hair is about .007

400brian · Post by **400brian** » Mon Oct 16, 2006 1:37 am

I've heard some folks say the best tool for setting timing is a buzzer, the advantage being that you can watch what you are doing, and just listen for the change in tone as you rotate the stator plate. In any case, being as I have an ohm meter as part of my aging Heathkit engine analyzer ( tach and dwell meter ) I had figured to use it like Paul did.

For those of us old enough to have been schooled in points ignition systems, it was generally accepted that you could not accurately set used points with a feeler gauge.
We used to prove that with the dwell meter. My point is this: if you want your ignition system set to the most optimal, you need to pull the flywheel and take a good look at your points, if they show any wear, the contacts need to be at the least filed flat , or better yet, replace them with new.

As to Paul's question of what type of ignition he has. Does the flywheel say "ND" on it?
( nippondenso ) According to my SM, your '73 X8 should have a Denso system.
'73 X8 Serial number 2,551-20,000

Danzig · Post by **Danzig** » Mon Oct 16, 2006 3:29 pm

My fluke meter has a tone control on it too..........so I do have the buzzer also to boot!! :rolleyes:

Post by **ICCSF 108** » Mon Oct 16, 2006 3:37 pm

I'm not sure on the CCW points motors as we never worked with them very much but on the Hirths, Sachs, & JLO's we could never adjust the timeing by moving the plate as the holes in the plate to move the timing were to sloppy & it would always change the timing between the 2 cylinders, so what I did was just move the points by just bending the stationary part of the points either togather or apart (very slightly), by doing this your not changing the gap THAT much from the points setting specs. & I could get the timeing dead on - on both Cylinders. Also a buzzer or as we called it a buzz box is the best way to adjust timing as you will hear the opening & closing of the points way faster & easier than you will see it in a light. Also the timeing on some motors with points is set at retard & on some are set at full advance so make sure you read what is correct for you make & model of motor.

Just my $.06850

Kenny

Danzig · Post by **Danzig** » Mon Oct 16, 2006 8:51 pm

I am curious why a dwell meter wasnt incorporated in when changing or adjusting points.

Post by **ICCSF 108** » Mon Oct 16, 2006 9:55 pm

Correct me if I'm wrong but doesn't a motor have to be running to use a dwell meter?
& weren't GM products the only vehicles that had a window in the distributor cap so you could use a dwell meter to adjust the pionts while the motor was running??
Also wasn't a dwell meter not used on dual points dist. unless you blocked off one set of points from firing??
Also when working on the clock or by labor flat rate why would you spend more time cking something that was already within specs??
Remember the K.I.S.S. method of thinking!!! Maybe that is why all the motor MFG. except Cuyuna & Xenoah went to CDI by the Mid 70's.
Just my $.06850 worth
Ken

Danzig · Post by **Danzig** » Mon Oct 16, 2006 10:13 pm

A motor does not need to be running to set the dwell, it only needs to turn over.

GM is one brand specific that had the window on the distrbutor, again the motor does not need to be running, just turned over. A sled with electric start could substitue for this I suppose.

Very easy to block off one set of points either unhook the white wire or red wire leading to the points you want to block off or unhook the points/condensor also.

I didnt know while working on a sled I was being timed, wow if this were the case I owe myself some back pay then. No warranty either.

I also would not work in a garage that based the job is based off flat rate, flat rate is for the dealerships as far as I am concerned.

Post by **ICCSF 108** » Tue Oct 17, 2006 12:11 am

Well Paul I have never worked a shop that went by the book or used flat rate either but when your useing an hourly rate to repair something like we used to in our shop I just couldn't see over charging for doing needless work either.
I guess what I'm trying to say is that if a particular snowmobile motor calls for a point gap between 0.012-0.016 so you have .004 to play with for error why would it be so important to put a dwell meter on it??? I would think a person would want the over all timing on both cylinders to be exact & not worry so much about .001 or so differance in point gap. good question for some others to comment on here I would say????
Yes your right about a motor not needing to be running to ck the dwell, BUT if I remember right ( & I have to admitt that it's been many years since I used a dwell meter, like maybe around 30, & maybe the Dwell Meters out there today are a lot better than the hand held ones we had in the early 70's) the old hand held ones if the motor wasn't running had a whole lot of deg./dwell bounce when the motor was being cranked vs. running.

Now I don't have the answer to this question & maybe you or someone else does, but would the deg. of dwell for .016 point gap on a snowmobile be the same as on an automobile using the same points gap???????

Kenny

Danzig · Post by **Danzig** » Tue Oct 17, 2006 12:31 am

You have alot of good points Ken.

The last time I used a Dwell meter was in 1986, working on an AMC engine, yes I was 16yrs. old then too, started turning wrenches at age 14, this is what happens when your father is/was GM technician. It was the hand held type also as you described. Back then you know what I am going to say next, those distributors were pulled out and an HEI was put in place in the GM field. GM is my backround of choice.

I do know in the automotive field that the point gap doesnt need to be perfect but close,I believe on most auto's point gap was .032?? Oh well, pointless here.

I dont have an answer to your last question either.

400brian · Post by **400brian** » Tue Oct 17, 2006 2:04 am

As I've mentioned recently, we have my brother's wedding coming up this weekend, and we have two '55 Chevys to get running. Anyway, I've used a dwell meter in the last week, and a Heathkit oscilloscope just tonight.

I know you can get a dwell reading spinning the engine with the starter, but I've never needed to try it.

My Heathkit dwell meter is set up for 4, 6, or 8 cyl engines, not sure how you would take a reading off the individual cyls of the CCW.

However, just tonight, I was reading the manual for the scope ( I bought this off ebay a couple of years ago, and haven't really used it before ) and it mentions using it on 2 cycles, so I guess I could analyze the sled if I wanted to. My biggest problem with the scope is that my limited training was 30 years ago, and experience would be a big plus here.