Author Topic: The only thing SCREAMING now is the bike on the highway! (Read 16598 times)

TwoTired · « **Reply #100 on:** February 27, 2007, 01:42:18 PM »

I don't know what scales are available on the switch settings of your unit. Or, if it is calibrated for wasted spark ignition systems, which you have.
The points open once each revolution of the crank. And, autos usually fire every other revolution so 4 cylinder setting operation may be off by a factor two for all readings.

To connect, you electrically clip across a points set. Either point set will give you an RPM indication. But, for dwell, each points set is measured individually.

The dwell relates to the gap setting. This is how you adjust dwell.

If you are going to adjust dwell and dynamic timing, you should review the FAQ and note the article describing shimming of the points plate.
Setting dwell and timing with the points plate moving around is...challenging.

Cheers,

eldar · « **Reply #101 on:** February 27, 2007, 02:25:05 PM »

On some dwells, you use the 8 cylinder reading and halve it. have you done a google on your meter?

medic09 · « **Reply #102 on:** February 27, 2007, 07:49:54 PM »

Okay, so first the "I told you so" moment for Lloyd/TT.

Sure enough, I checked my carb synch and it was off again.

He was right, must be coming down off all those wheelies.

Resynched. Have installed hotter plugs (D7EA). Checked dwell, relying on something in the Clymer's. They note that "on a 4-cylinder scale, the correct dwell would be 46-49" degrees. Just before that they point out that for these bikes what one really needs is a meter for 2 cylinder engines, since one set of points controls 2 cylinders. Why didn't I think of that before I bought a meter? Mike Nixon also notes in his booklet that nearly all these meters are automotive, as TT already did. In any case, since I was hovering around 50 degrees or a little less, and it's not finely calibrated, and the strobe check is good, I figure it must be pretty close. Adjusted idle, but that was before I checked the synch; so I may have to do that again in the morning.

Hard to tell till morning, but I think the hotter plugs idea may be a real step in the right direction.

TwoTired · « **Reply #103 on:** February 27, 2007, 10:32:27 PM »

You see, this is really all just a test for the readers. Every once in great while I actually say something right. The test is for you readers to figure out when it is right?

But, joking aside, give yourself credit, too! You are doing the work, and reporting good progress. The bike's had almost 30 years to get into it's current state. If it takes a few extra days to become primo again, isn't it worth it? And, I dare say you are learning more about the bike, so if something goes awry later, repairs will be made much faster and with less effort. Just remember to share your knowledge with those seeking answers later.

Hey, how'd I get on this box?

Cheers,

lassenc · « **Reply #104 on:** February 28, 2007, 12:18:45 AM »

Check the spring on the chokebar, if you can call it that.

I had lost mine, so 3 and 4th could move freely and would wobble around when riding, causing a problem, when the throttle was fully opened fast.

Just check it

mlinder · « **Reply #105 on:** February 28, 2007, 05:14:01 AM »

He yMedic, I'm going to install D7EA's this morning before I head to work.
Again, mine has no trouble starting, but needs 15 minutes total of warmup time before it actually runs reasonably well.
I have to say, that the new pipes already make this bike run about 3 times better than 4 into 1 I had on here. This was primarily an issue with me being unable to get #1 header to stay tight to the head :/

Fresh air at the beginning of a header screws everything up.

Anyway, yeah, gonna try D7EA's today. Supposedly its 34 degrees out, with a high of 45 today, so I think it may help.

eldar · « **Reply #106 on:** February 28, 2007, 06:22:02 AM »

I put in D7s to combat my rich running. However, you might to keep it as a cold weather thing. If you average temp in the summer hits above 80, maybe go back to the D8s once you get the idle mix tuned up.

medic09 · « **Reply #107 on:** February 28, 2007, 06:37:00 AM »

Quote from: eldar, Master of the K8 Thunder! on February 28, 2007, 06:22:02 AM

I put in D7s to combat my rich running. However, you might to keep it as a cold weather thing. If you average temp in the summer hits above 80, maybe go back to the D8s once you get the idle mix tuned up.

I think that's what TT meant, as well. For now, our highs are only hitting about 50F. I'll switch them back later in the spring.

medic09 · « **Reply #108 on:** February 28, 2007, 08:56:53 AM »

Okay, here's a thought. Lloyd was right that my carbs were out of synch only a few days after synching them. How do I know it won't happen again soon?

Okay, time to go see if it'll start...

andy750 · « **Reply #109 on:** February 28, 2007, 09:03:57 AM »

Good luck Medic -you are inspiring us all :-) and we are learning through you! Keep us posted on progress.

As for carb synching - if they werent that much out second time around then chances are this wasnt the real problem. If you were to synch your carbs 5 times over 5 weeks I bet you would see small differences each time. Point is there is always going to be some variation. If its a lot of variation then you have an unknown variable that is affecting the measurements. It could be the measurement device, ambient temp, air pressure, or the carbs themselves (and there are a few parts there that would affect it).

good luck,
Andy

mlinder · « **Reply #110 on:** February 28, 2007, 09:06:36 AM »

Quote from: medic09 on February 28, 2007, 08:56:53 AM

Okay, here's a thought. Lloyd was right that my carbs were out of synch only a few days after synching them. How do I know it won't happen again soon?

Okay, time to go see if it'll start...

GOod Luck!

Was raining/slight snowing this morning when I left for work, so didn't change plugs yet. Will do at lunch time here in front of my work

medic09 · « **Reply #111 on:** February 28, 2007, 09:22:11 AM »

Quote from: andy750 on February 28, 2007, 09:03:57 AM

Good luck Medic -you are inspiring us all :-) and we are learning through you! Keep us posted on progress.

As for carb synching - if they werent that much out second time around then chances are this wasnt the real problem. If you were to synch your carbs 5 times over 5 weeks I bet you would see small differences each time. Point is there is always going to be some variation. If its a lot of variation then you have an unknown variable that is affecting the measurements. It could be the measurement device, ambient temp, air pressure, or the carbs themselves (and there are a few parts there that would affect it).

good luck,
Andy

I realize that, too. When I rechecked them, they were more than 20mm off the index carb. I had them within about 4mm. No matter how much I steady the screw, when I tighten the retaining nut it changes the setting. AND if I tighted the nut the least little bit too much, it seems to torque the linkage and mess up the whole thing!

So, I've got them back within that 4mm +/- tolerance. We'll see. I'll have to recheck the idle now.

medic09 · « **Reply #112 on:** February 28, 2007, 09:26:18 AM »

SORRY, that was CM not MM! And I've been working within tolerances of less than 2cm variance.

Yeesh, imagine if I switched measures like that while doing drug calculations...

eldar · « **Reply #113 on:** February 28, 2007, 10:34:26 AM »

Well you want to try and get them within 1 inch if possible. That is the bad thing about mercury sticks though. They bounce around so much that it is hard to use them. This one place where I think vacuum gauges and the carbtune are better.
Most people go by this rule, "if you pull your carbs, you need to re-sync." Now I dont know if it is all that bad but if you ahve to pull multiple times, then it is probably a good idea.

medic09 · « **Reply #114 on:** February 28, 2007, 11:52:58 AM »

I use a Carbtune. The 2 cm tolerance I settled for is a bit under an inch. The question remains how to keep it there.

Just had my wife's bike out for a quick run. The wind nearly blew me sideways. My Honda ready for another test run, but I don't think I'll go very far today.

mlinder · « **Reply #115 on:** February 28, 2007, 01:54:57 PM »

Things any better?

I put in the D7's. kick starts without choke after 4 hours of sitting. Needs about 2 minutes to get a clean throttle pull, and 4 minutes of riding to get to operating temperature and smooth riding now.
The D7's helped for sure, though at least half my problems were solved by going to the 4 into 4 exhaust that Paulages had.

medic09 · « **Reply #116 on:** February 28, 2007, 02:20:34 PM »

The wind is blowing so hard I was discouraged from riding my bike very far. I don't like moving in a straight line while pushed over into a 45 degree lean.

It did start up a bit easier, especially using TT's suggestion about part-open throttle on start. The D7s helped some, too. Still not easy starting (more than one attempt from cold standing), but easier than it was. Takes a bit to warm up, but at least it's achievable now. Rides just fine once I'm on the road. I'm not sure that I'm quite happy with the idle, but I'll wait a bit before fiddling with it any more. It seems to need to idle higher than I would have thought. I think I'm going to need a few days of riding and running it now to see what have I missed...

We're getting there!

I really appreciate all the generous help on this forum. I learn a lot, and I enjoy my bike much more.

mlinder · « **Reply #117 on:** February 28, 2007, 02:30:55 PM »

Quote from: medic09 on February 28, 2007, 02:20:34 PM

The wind is blowing so hard I was discouraged from riding my bike very far. I don't like moving in a straight line while pushed over into a 45 degree lean.

It did start up a bit easier, especially using TT's suggestion about part-open throttle on start. The D7s helped some, too. Still not easy starting (more than one attempt from cold standing), but easier than it was. Takes a bit to warm up, but at least it's achievable now. Rides just fine once I'm on the road. I'm not sure that I'm quite happy with the idle, but I'll wait a bit before fiddling with it any more. It seems to need to idle higher than I would have thought. I think I'm going to need a few days of riding and running it now to see what have I missed...

We're getting there!

I really appreciate all the generous help on this forum. I learn a lot, and I enjoy my bike much more.

Riding my bike was almost a chore before yesterday. Due to the help I've received from people on this board, it's now a joyful experience.
I still wonder if your hard start problem is due to float height. Not having enough fuel down there could cause the problem, I'm pretty sure.
I will have to keep an eye on these D7's, the weather is fluctuating wildly right now, I rode in to work this morning in the rain, with a couple of snowflakes floating down. RIght now the forcast says it's 42 out, but I dont believe it, closer to 50, with the sun shining and a few rain drops (wtf?), and would hate to overheat the engine with hotter plugs, though I still think I'm in the safe range with the temperature we are at here. I think at 60+ I'll switch back to D8's.

eldar · « **Reply #118 on:** February 28, 2007, 02:46:21 PM »

Well if you run rich, your engine will not generate as much heat. I ran D7s all last summer and never had an issue. But then, I was running rich. Unless it gets very hot or you idle a lot, it should be ok. But you can always move back to the D8 once things are fully tuned.

TwoTired · « **Reply #119 on:** February 28, 2007, 04:26:36 PM »

Part of the decision to switch back to colder plugs should be made using the plug deposits as a guide. If you routinely run with white or no deposits on the plug insulators, you are already running lean or too hot. A hotter plug will put you closer to preignition conditions when the air is warmer and the engine's cooling fins don't work as effeciently. (colder air makes the fins more effective at wicking heat away from the combustion chamber.)

However, if you have tan or darker brown deposits, you don't need to worry much about going to colder plugs until the weather gets pretty darn hot out.

A couple of points for the casual reader to think about. We're talking 750s here or engines that the manufacturer specified D8EA heat range plugs. And, where the bike has been modified with induction or exhaust changes that effect carb mixtures.

Cheers,

medic09 · « **Reply #120 on:** February 28, 2007, 07:26:49 PM »

A few little 'addenda'.

I just got the shop manual that I bought on Ebay. Way overpaid, but worth having the print manual in front of me. Bonus - I think the Dec. '77 edition has even better illustrations than the earlier editions with the updates. Helpful for a novice like me.

So, looking through it I notice they recommend the same as TT, trying D7EA plugs for colder climes. For "High Altitude Adjustment" they only recommend adjusting carburetor idle speed. I found that interesting, since Triumph recommended (in the manual for my yet to be rebuilt 75 Trident) rejetting.

For adjusting carb idle, the manual recommends starting with #2. I know that's our index carb; but would it make much difference? When I set the idle today, I started from one side and worked across. Started at #4, actually.

For rebuilding the carbs, they recommend not to remove the slow jet ("The slow jet must not be removed..."), since it is pressed in. Hmmmm.....

eldar · « **Reply #121 on:** February 28, 2007, 07:37:44 PM »

Well they us #2 as the index since you adjust the carb sync to that carb. So it stands to reason that it is best to start there for all adjustments. Wether or not it makes a difference, I dont know but if nothing else, it at least gives you a starting point. On this question, I think hondaman or mreick would give the best input.

And as tt elaborated on, plug selection should be determined by your state of tune and the subsequent plug readings.

upperlake04 · « **Reply #122 on:** February 28, 2007, 08:11:05 PM »

Right, #2 is without adjustable linkages, and #1,3, and 4 are synched to it. Pic number is mislabled.

medic09 · « **Reply #123 on:** February 28, 2007, 08:22:51 PM »

Quote from: upperlake04 on February 28, 2007, 08:11:05 PM

Right, #2 is without adjustable linkages, and #1,3, and 4 are synched to it. Pic number is mislabled.

Right, that's why it's the index for synching. But why should it be the index for idle adjustment?

upperlake04 · « **Reply #124 on:** February 28, 2007, 08:33:06 PM »

Medic - are we talking about idle mix adjust on each carb or idle speed ,all carbs together with the thumbknob between 3 and 4?

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Author Topic: The only thing SCREAMING now is the bike on the highway! (Read 16598 times)

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