Author Topic: 1976 CB500/550 Project "Squirrel" (Read 282002 times)

SOHC4 Cafe Racer Fan · « **Reply #1825 on:** July 04, 2017, 07:43:26 AM »

Ron,

Your friends were correct, but so were you in your comments after the search -- although I would have kept those to my inner monologue.

I was in LAX going through customs (returning from vacation in London with my girlfriend and family). Customs separated me from my 4 traveling companions to search my bag and ask me questions. It was a 3-ring circus because they were also searching people with make-shift, taped up boxes as luggage that spilled their contents everywhere. I took it upon to start asking them some questions -- Is it normal for you to separate a family group traveling together? How am I going to find my travel companions? Then, they asked me what I did for a living? (At the time I was a lawyer at a firm and was defending the LA City mayor and councilmembers, and the Beverly Hills Police Department. For some reason they no longer had any interest in my bag, and sent me on my way. Of course, volunteering that you are a lawyer (rather than being asked) usually gets you in more trouble, like the sort you encountered.

riverfever · « **Reply #1826 on:** July 04, 2017, 08:06:51 AM »

Yesterday I got the needle clips swapped back to the 2nd slot. I did not get to fire the bike up though because I got a call to go fish some private water and couldn't resist. Today I will take the bike out for a quick warm up and then come back and sync the carbs again and see how things seem. I haven't tried this combination yet so I'm hopeful.

riverfever · « **Reply #1827 on:** July 04, 2017, 09:04:36 AM »

Testing Flickr here:

IMG_0349 by cneumann2000, on Flickr

These are idle chop results after a 5 minute idle.

calj737 · « **Reply #1828 on:** July 04, 2017, 09:32:45 AM »

You've upgraded to a SOHC 5?

riverfever · « **Reply #1829 on:** July 04, 2017, 10:29:02 AM »

The name of this build has been changed to The Compensator. I just had that there as my control to refer to.

I went out this morning to warm the bike up and that horrible stumble at 1/8 and 1/4 throttle position is gone. Carbs synced up nicely. I have three sets of clean plugs and will head out and do a 3/4, 1/2, and 1/4 chop and see if the results come back tolerable for this situation. Fingers crossed.

riverfever · « **Reply #1830 on:** July 04, 2017, 01:34:32 PM »

Just did a series of chops at 3/4, 1/2, and 1/4 ranging in altitudes from 7200 to 7800 feet. Trying to get pics uploaded now but I feel like 3/4 and 1/2 are too lean and I can't believe I'm typing that. The chop from 1/4 throttle was at 7800 and it looked stunning. I do not think I'd feel comfortable riding the bike down the mountain though for fear of it being way too lean. Right now, I think the motor will be super happy from 8,000 to 10,000 feet. I'm actually considering ordering 110 mains in the hopes that they richen the mixture at 1/2 and up. It would be nice to get to a point where I could go further into the mountains as well as go down to Colorado Springs and not worry about doing any damage. The issue at 1/8 and 1/4 throttle is totally gone.

Here are some pics. These are 3/4 throttle 1-4:

IMG_0387 by cneumann2000, on Flickr

IMG_0388 by cneumann2000, on Flickr

IMG_0389 by cneumann2000, on Flickr

IMG_0390 by cneumann2000, on Flickr

Here's 1/2 throttle 1-4:

IMG_0391 by cneumann2000, on Flickr

IMG_0392 by cneumann2000, on Flickr

IMG_0393 by cneumann2000, on Flickr

IMG_0394 by cneumann2000, on Flickr

riverfever · « **Reply #1831 on:** July 04, 2017, 01:36:31 PM »

Here's 1/4 throttle 1-4:

IMG_0396 by cneumann2000, on Flickr

IMG_0398 by cneumann2000, on Flickr

IMG_0399 by cneumann2000, on Flickr

IMG_0400 by cneumann2000, on Flickr

SOHC4 Cafe Racer Fan · « **Reply #1832 on:** July 04, 2017, 08:53:32 PM »

Quote from: riverfever on July 04, 2017, 09:04:36 AM

Testing Flickr here:
IMG_0349 by cneumann2000, on Flickr

These are idle chop results after a 5 minute idle.

RC211V!
https://en.wikipedia.org/wiki/Honda_RC212V

Camrector · « **Reply #1833 on:** July 04, 2017, 09:17:27 PM »

Just out of curiosity river, with such changes in altitude can you ever really dial it in?
Are roadside Jet changes something you have to deal with? I'm at 600ft above sea level and that doesn't change for about 500 miles give or take a couple hundred feet.

SOHC4 Cafe Racer Fan · « **Reply #1834 on:** July 04, 2017, 09:25:37 PM »

It'll definitely be a challenge -- even EFI bikes struggle with the altitude there.

riverfever · « **Reply #1835 on:** July 05, 2017, 07:39:21 AM »

I don't think so. I'm just looking for a decent middle ground. Yesterday was the best this bike has ever run in 4 years. I ordered 110 mains last night and will put them in as soon as they get here and then see which looks better all around (110 or 105). I've always wondered if it was silly to have this bike here and it may be.

I think originally, and I got carried away with things (you guys are really good at spending my measly pittance), I wanted something that I could ride and determine if motorcycling was going to be something that I enjoyed. If it turned out that I did, my plan was to then look for something that would be more appropriate for this area (KTM Adventure, BMW, etc.). Unfortunately, I haven't been able to actually ride the thing that much until very recently. So I'm hoping that's about to change so I can start to enjoy two wheels again (I miss cycling) and then start looking for a used a 990 in a year or two. I just didn't want to buy one on a whim and then find out that motorcycles scared me.

Camrector · « **Reply #1836 on:** July 05, 2017, 07:53:13 AM »

Not many things better in life than riding a moto on a twisty road, heading to a trout stream.

RAFster122s · « **Reply #1837 on:** July 06, 2017, 04:07:10 PM »

Cal, thanks for the lesson, I went the wrong direction. Guess it was dropping down by 5 on the jet size, but I have not looked it up...
You are on it.
I thought it was a 77-78, should read the thread title , huh?
Did not recall the bike correctly, thought it was a mild built 550...
Apologies, was not intending to misdirect just remembered Mark's advice about jetting and thought it might be beneficial to look up or ask HondaMan his thoughts since he is in the mile high city and he and his brother or one of them owned a 550 for a while.
Since he solved the puzzle it might help if things were beyond clip height or other adjustments to Fuel Air...
Had it backwards on altitude, not been thinking clearly as having problems with insomnia.

David

quote author=calj737 link=topic=127186.msg1930588#msg1930588 date=1499166039]
A couple things wrong with that RAFS: at higher altitude, there's a lower air pressure which would want less fuel, not more to maintain the same A/F.

Chris' bike is not a 77/78, its a 500 motor with a 550 head, O/S valves, and early model carbs. Stock airbox, but a MotoGP 4:1. So there's no "stock jetting" that will be relevant. His issue is a great deal more to do with needle and screw adjustments than jets. As his issue surfaces at different throttle positions- finding the correct blend of settings to carry him through is the challenge. Yeah, altitude is causing a tad of issue as well since he bounces between 4,500 and 9,000+. Welcome to mechanical carbs

[/quote]

riverfever · « **Reply #1838 on:** July 06, 2017, 05:27:41 PM »

I'd like input on two things.

1. If you look back at the pictures I posted above from the 1/4, 1/2, and 3/4 chops you will notice that #4 always looks different. At 3/4 and 1/2 throttle it's more noticeable but this plug ALWAYS is different and at lower throttle positions (like 1/4) #4 is the only plug that is wet with fuel. It's not wet after 1/2 and 3/4 chop but it is darker. I have verified fuel level in that bowl and it's good. Have nice blue spark. I have always dealt with issues on cylinder 4 and as I thought about things today, the only constant is that carb body. Much earlier in my thread I posted a picture of the inside of that body and it is badly eroded. I am concerned that additional fuel is getting past the main jet o ring and messing up things in that cylinder. After a 5 minute chop I cannot touch headers 1-3 but 4 is significantly cooler. James is looking for a 627B body for me.

2. Today I revisited the idle tune after messing with the clips and syncing the rack again and I had to make changes. IMS screws for 1-3 are 1/2, 5/8, and 5/8 OUT (I had the IMS screw totally closed for number 4 and the plug was still almost white). According to the CARB FAQ, these screws are most effective from 1 to 2 1/2 turns out. I am concerned if I need to consider going to 40 idles.

What do you all think of both of these? Likely I need a different carb body and next size bigger idles? Thanks.

calj737 · « **Reply #1839 on:** July 06, 2017, 05:32:29 PM »

When you vacuum synched them, were they close in their current readings?
I would encourage you to revisit the valve clearances (or did you just do that after resetting your timing?) before vacuum synch.

As long as you know all four cylinders are firing and drawing equally, then it's logical to suspect the carb body itself.

Here's an idea I've recently contemplated: run different jets in each carb to see which configuration is preferred. Saves some time between switching all four!

One good plug chop tests an entire range in 1 run!

riverfever · « **Reply #1840 on:** July 06, 2017, 05:47:15 PM »

Sync was the closest I've ever had it and all carbs were at 8.5-9 (not sure if that measured in pounds or inches). I reset the valves when I swapped those head pucks and before the timing. I know you and I talked about that fourth body months ago and that this day may come. Think it's here.

SOHC4 Cafe Racer Fan · « **Reply #1841 on:** July 06, 2017, 05:54:15 PM »

I saw you were looking for a spare carb body. Was that carburetor having difficulty maintaining vacuum to synch with the others?

riverfever · « **Reply #1842 on:** July 06, 2017, 05:57:44 PM »

No I wouldn't say there was anything unusual there. I'll try to post that pic of the inside again. It's ugly. Squirell is backed in a corner and not digging it.

riverfever · « **Reply #1843 on:** July 06, 2017, 07:08:59 PM »

IMG_0408 by cneumann2000, on Flickr

SOHC4 Cafe Racer Fan · « **Reply #1844 on:** July 06, 2017, 08:16:07 PM »

Crusty the Clown 🤡. Yes, I think you need a new one. Are the other bodies fine in comparison?

riverfever · « **Reply #1845 on:** July 06, 2017, 09:47:04 PM »

I pretty much knew it. I have two members looking for me and will hopefully know something tomorrow. The rest of the bodies were fine. Not sure what happened to this one but that's how it was when I purchased the project.

Can anyone tell me if the IMS screws are less than a turn out, if that's indicative of a need to move up on the idle jets? Latest idle chops seem to point to that. It appears that I'm not quite out of the tuning woods just yet but now I'm really close and, better yet, have a significantly better understanding of how all of these things (like the different circuits of the carbs, timing, etc.) interact. The last few weeks have been very educational.

Stev-o · « **Reply #1846 on:** July 07, 2017, 04:30:41 PM »

Quote from: SOHC4 Cafe Racer Fan on July 06, 2017, 08:16:07 PM

Crusty the Clown 🤡. Yes, I think you need a new one.

+1 Crater Lake! WTF?! Bill B has 1.......

riverfever · « **Reply #1847 on:** July 08, 2017, 09:11:08 AM »

I'm waiting to hear back from Bill and James.

I have a set of O22A carbs that I could use but it would be a lot less work to just find a replacement 627B one and swap it in.

riverfever · « **Reply #1848 on:** July 09, 2017, 11:08:38 AM »

In the event that I am not able to find a 627 replacement body, I will use the O22A rack that I have. Just want to confirm there are no issues wth me using my known good guts from the 627 carbs in those other bodies. Anyone?

riverfever · « **Reply #1849 on:** July 10, 2017, 01:18:39 PM »

I gave up searching for a replacement 627B body and just decided to revisit the O22A rack that I had. I swapped everything over yesterday, and was able to get them bench synced and back on the bike today. With the 627 carbs, the fourth header never got as hot as the others and that plug was always wet. I still need to warm the bike up with a ride and then vacuum sync the carbs but it sounded like a totally different bike when I started it. It ran for less than a minute and that fourth header was hotter than it's ever been so that's a really positive sign.

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Author Topic: 1976 CB500/550 Project "Squirrel" (Read 282002 times)