Author Topic: 1976 CB500/550 Project "Squirrel" (Read 281827 times)

riverfever · « **Reply #1875 on:** July 23, 2017, 08:56:29 AM »

Without a doubt, the performance is better with the 105 mains. Obviously, I don't want anything bad to happen with the motor because of improper a/f ratio but I also don't know if I'm overthinking it.

Typically I run 87 but I do know that at the last fill they were out of everything but 91 so that's what was used for these chops. How would 85 differ in terms of color?

riverfever · « **Reply #1876 on:** July 23, 2017, 09:09:53 AM »

Sean...this is interesting. I'll have to take a better look down inside the plugs because (and I know the picture used in this link is horrible) the tips of the plugs look pretty darn similar to me. Which, as you're implying, can be misleading.

http://kawtriple.com/mraxl/carb/plugchop.htm

Stev-o · « **Reply #1877 on:** July 23, 2017, 09:19:52 AM »

Quote from: riverfever on July 23, 2017, 09:09:53 AM

Sean...this is interesting. I'll have to take a better look down inside the plugs because (and I know the picture used in this link is horrible) the tips of the plugs look pretty darn similar to me. Which, as you're implying, can be misleading.

http://kawtriple.com/mraxl/carb/plugchop.htm

You hanging around the Kaw Triples forum now?! You should buy one.
A lot of good info there, the cutaway examples of the plugs is excellent.

calj737 · « **Reply #1878 on:** July 23, 2017, 09:45:10 AM »

Quote from: riverfever on July 23, 2017, 08:56:29 AM

Without a doubt, the performance is better with the 105 mains. Obviously, I don't want anything bad to happen with the motor because of improper a/f ratio but I also don't know if I'm overthinking it.

Typically I run 87 but I do know that at the last fill they were out of everything but 91 so that's what was used for these chops. How would 85 differ in terms of color?

You did the 105 chops with 87 but the 110 chops with 91?

riverfever · « **Reply #1879 on:** July 23, 2017, 09:45:53 AM »

Haha no! I was just searching and found that article and thought it was good and supported exactly what Sean was saying. I just looked at several plugs from yesterday. I have no way of knowing what chop they were from bc I just have all the used ones in the seat tray but even plugs that appear lean at the tip do in fact have color way down past the threads. Also the second pic from that article calls the plug on the right slightly lean and I would have thought that was very lean. Interesting stuff.

Maybe the plugs from when you screamed "Don't touch it!" Had good color down there bc the thing was running super.

riverfever · « **Reply #1880 on:** July 23, 2017, 09:49:35 AM »

The 110 jets were definitely with 91 as were the 105 pics from yesterday. However, the pics (previous page near top) of 105s likely had 87 octane. Wonder what the color looked like down further?

Stev-o · « **Reply #1881 on:** July 23, 2017, 09:50:58 AM »

Quote from: riverfever on July 23, 2017, 09:45:53 AM

Maybe the plugs from when you screamed "Don't touch it!" Had good color down there bc the thing was running super.

I think so! I do think you are over thinking it. How many miles have you put on it this month?

Are you a teacher or something? Seems you really like tests!

SOHC4 Cafe Racer Fan · « **Reply #1882 on:** July 23, 2017, 10:00:00 AM »

Don't let the chops get in the way of enjoying it, if it is running well and not bluing your pipes.

seanbarney41 · « **Reply #1883 on:** July 23, 2017, 10:14:33 AM »

too high octane and plugs will be sooty but engine will perform ok until the plugs soot up so bad that they foul. The soot can be burned away by a good hard blast...so full throttle plug chops are gonna look ok, anything less than 3/4 throttle is gonna look rich.

I used to always run 93 in my bikes during the summer time, just for the added detonation protection. Lately, I've been useing 89 or 91 and getting better part throttle performance.

I forgot what your engine build is as far as compression ratio...stock?, 87 to 89 should be fine. Higher compression? you may need 91 or higher.

My advice to you is if you are getting good performance, and plug readings show nothing dangerous, put the damn spark plug wrench away and go for a ride.

calj737 · « **Reply #1884 on:** July 23, 2017, 11:34:31 AM »

Quote from: seanbarney41 on July 23, 2017, 10:14:33 AM

too high octane and plugs will be sooty but engine will perform ok until the plugs soot up so bad that they foul. The soot can be burned away by a good hard blast...so full throttle plug chops are gonna look ok, anything less than 3/4 throttle is gonna look rich.

I used to always run 93 in my bikes during the summer time, just for the added detonation protection. Lately, I've been useing 89 or 91 and getting better part throttle performance.

I forgot what your engine build is as far as compression ratio...stock?, 87 to 89 should be fine. Higher compression? you may need 91 or higher.

My advice to you is if you are getting good performance, and plug readings show nothing dangerous, put the damn spark plug wrench away and go for a ride.

The compression ratio is less an issue for Riverfever; it's the elevation he rides/lives at. He's well above 6,500 often peeking at nearly 9,000 ft. When that happens, octane does effect combustion more.

Chris I'd re-run the 110s one last time on a simple, regular ride with 87 and put a good amount of miles down 75-100 and see how it performs overall. Carry extra plugs and a wrench just in case she bails on you.

RAFster122s · « **Reply #1885 on:** July 23, 2017, 10:49:23 PM »

The tips are not a good read of color on the plugs, it is that of further down the threaded portion that should be read.

This is ethanol free gas, right?

David

riverfever · « **Reply #1886 on:** July 24, 2017, 07:57:17 AM »

When I swapped to the O22A carbs I immediately noticed the bike ran better than it ever has. That was with 38/105 and clips in the second slot from the top. I put 40 idles in believing that things were too lean at idle but noticed that while the bike idled okay it would die when coming to a stop. This has always been an issue but NOT with the 38 idles and the new carbs. Yesterday I put 38s back in and the motor runs great again.

Sean...the hold up for me is that I have been paying very close attention to the tips of the plugs and not the color further down. After all of this work I do not want anything bad to happen to the motor. I'm debating whether I should use clean plugs and get things where I think they need to be and then install brand new plugs and chop them (for idle, wot, and 1/2) just to verify that things do have color at those throttle positions?

Cal...the bike stumbles even at 1/2 to 3/4 throttle with the 110 mains. At wot it completely shuts down.

David...this is blended fuel.

riverfever · « **Reply #1887 on:** July 24, 2017, 12:50:41 PM »

I put away the plug wrench this morning and decided to just go for a ride. Ended up putting 115 miles on the bike. Altitude was between 7 and 9 thousand feet. I would say that I spent a lot of the time in fourth gear between 5-7 thousand rpms. I spent a fair amount of time at that 1/4 throttle position. I thought the bike did great. No stumbling or hesitation anywhere. I kept a close eye on the headers and there is no blueing at all. Just a nice golden tone starting to appear. Again specs are 38/105 (I pulled the 40 idles yesterday) and clips in the second position. For this ride I went up the mountain to the next town higher and over a small mountain pass (probably topping out at 9) and then it dips down in elevation (mostly around 8 thousand). Out and back ride so climbed up on the return trip and then dipped down into town. I was very surprised when I pulled the plugs at home and found them all showing very rich. I'll get a picture up a bit later. My only guess as to why they show so much color after this ride in comparison to the chops is because during the chops the rpms are so much higher. Definitely this is the case at wot but I know it's also the case when I've done a 1/2 throttle chop. Rpms are probably closer to 9 thousand for a wot and still really high for the 1/2. Does that sound reasonable? There seems to be a whole hell of a lot that depends on HOW the bike is being ridden (and I know Cal and I have talked about this and I've been ribbed over babying it before).

I guess what I'm thinking is that I'm still really damn close dependent upon how the bike is ridden. If I go up in elevation I could get by with gearing down and keeping the rpms higher and plugs clean. If I drop to 6 thousand feet I could decrease the rpms slightly and the increased oxygen is probably still going to have me in an acceptable area. Am I thinking correctly?

calj737 · « **Reply #1888 on:** July 24, 2017, 01:39:33 PM »

Sure.

Regarding plug chops and riding, WOT is a throttle position, not necessarily a gear and rev combination. Technically, you could do a WOT chop in 2nd gear as you're measuring the throttle position...

riverfever · « **Reply #1889 on:** July 24, 2017, 01:45:14 PM »

I wasn't very clear there. The only explanation for the difference today was due to lower rpms. That's likely fair to say right?

RAFster122s · « **Reply #1890 on:** July 24, 2017, 07:35:16 PM »

No, mixed riding and varying throttle and low throttle riding builds up deposits that show an average in some cases but often they really tell you little unless they are oily, which tells you you have oil control problems.
The whole point of putting new plugs in before a read is to isolate the running at that throttle position to put its deposits upon the plug, Not to hope the plugs are burned clean before you run your plug chop test.
So, unless you are using new or plugs with the porcellin cleaned, then your plug readings will not reflect the operation range you are looking to get a read upon.

If it is running well then don't mess with it further and enjoy it. Do not mess with what is not broken.

riverfever · « **Reply #1891 on:** July 26, 2017, 12:02:14 PM »

Okay I understand. I took the bike out for another ride this morning. I went from town up to about 9200 feet. I do have a very slight bobble at 1/4 throttle so I decided to drop down in altitude and see what happened. Before dropping down I pulled the plugs at about 7700 and they were every bit as rich as yesterday. I kept the rpms closer to 8 grand today and dropped all the way to 5700 feet. I rode for several miles and stopped to check the plugs and they were much cleaner and the bobble at 1/4 was gone. Unfortunately, I think I may be at a point of compromise here.

SOHC4 Cafe Racer Fan · « **Reply #1892 on:** July 26, 2017, 02:24:19 PM »

Quote from: riverfever on July 26, 2017, 12:02:14 PM

Okay I understand. I took the bike out for another ride this morning. I went from town up to about 9200 feet. I do have a very slight bobble at 1/4 throttle so I decided to drop down in altitude and see what happened. Before dropping down I pulled the plugs at about 7700 and they were every bit as rich as yesterday. I kept the rpms closer to 8 grand today and dropped all the way to 5700 feet. I rode for several miles and stopped to check the plugs and they were much cleaner and the bobble at 1/4 was gone. Unfortunately, I think I may be at a point of compromise here.

Sounds like it. There's a reason why Pikes Peak is a mutha of a 🏁 racecourse.

riverfever · « **Reply #1893 on:** July 28, 2017, 01:51:06 PM »

I wanted to post a picture of the plugs from a ride the other day. This was a ride between 7-9 thousand feet. Really considering moving the clips to the first position to see what happens. This seems very rich to me.

IMG_0529 by cneumann2000, on Flickr

SOHC4 Cafe Racer Fan · « **Reply #1894 on:** July 29, 2017, 06:59:01 AM »

That is pretty wet.

riverfever · « **Reply #1895 on:** July 29, 2017, 11:06:39 AM »

What a puzzle all of this tuning stuff is. I did make the change and clips are now in the first spot. The stumble at 1/4 throttle is gone but taking off from a stop is very lethargic. Feels like you're taking off in second gear. This morning I put the 40 idles back in and it helped out when taking off from a stop but it feels like it could still be a bit better. I did an idle chop with screws out 3/4 and results were pretty lean. At this point I don't think I'm going to do anything else until I take the bike out for a typiucal 15-20 mile ride and see what the plugs look like in that mid-throttle range. If I'm too lean there then I know the answer is clips back to second slot and 38's and just overly rich up here but able to drop down in altitude.

riverfever · « **Reply #1896 on:** July 29, 2017, 04:21:32 PM »

Need opinions please. This is after a 16 mile ride between 8000-8500 feet with most of the time spent at 1/4 to 1/2 throttle.

IMG_0587 by cneumann2000, on Flickr

It seems that 40/105 with clips in the first slot has me on the lean side and likely not being able to drop down to 6000 feet for a ride. While 38/105 with clips in the second slot has me on the rich side but being able to drop to 6000 feet easily. I suppose I could spend more time and try 42/105 with clips in the first slot but I don't know that I will. Of the two options I guess I'm more inclined to go with the tune that has me on the rich side up here and just know that I may have to change plugs more often.

RAFster122s · « **Reply #1897 on:** July 29, 2017, 06:03:42 PM »

Is your first spot from bottom or top of the positions available?

riverfever · « **Reply #1898 on:** July 29, 2017, 06:36:47 PM »

IMG_0357 by cneumann2000, on Flickr

calj737 · « **Reply #1899 on:** July 30, 2017, 03:54:28 AM »

What about going the other way completely? 100 mains, clip in 3rd/4th slot? Use 40 mains for your around town, the richer needle but smaller jet might be the sweet spot for 1/2-4/4 throttle at changing altitudes. A larger main never giving too much gas but the needle adding enough to prevent too lean

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Author Topic: 1976 CB500/550 Project "Squirrel" (Read 281827 times)