My Turn

Ha. I actually watched one of those movies the other day and my wife said, "WTF is this?"

I finally got around to installing the new jets. I ordered several different ones but decided to try the 90's. The motor seems much happier now. I just took it out for about 25 miles and still have all 4 cylinders running so that's a good sign. Now I need to vacuum sync them.
 
A while ago I ordered a left hand control. Well the one I got is kind of a pile. The kill switch is normally open and I need it to be closed. So tonight I installed a relay and got it working. Tomorrow I'll throw the fresh plugs in and do a run up the Pass and see how the plugs look afterwards.
 
So today I installed 4 fresh plugs and road down the pass a bit and turned around to head back up. I was just below 9000' in 5th gear running 70ish mph wide open with a UNI foam filter and the 90 main jets when I killed it. I coasted into a gas station and pulled the plugs to see how they looked. Here they are.

#1


#2


#3


#4


Now this is the first time I've done this but I thought these plugs looked very lean. However, this is not typical of how I ride this bike nor how I want to ride this bike. So I decided to throw them back in and go for a typical ride. I went up through Woodland and then up to Divide. I turned around at the light and came back through Woodland and pulled in the garage and killed it. Here are the plugs.

#1


#2


#3


#4


Now...I think 1 and 2 look really good but 3 and 4 appear to still be a touch rich. I still have not vacuum synced the carbs. Coils fire 1/4 and 2/3 so I think this is a sync issue with 3 and 4 (possibly a mixture screw issue as well). I think going with 85 mains would be a mistake. I'm getting damn close. Thoughts?
 
That's what I thought Solar. I feel like I've been throwing a decent amount of loot at this thing the last 11 months so I was about ready to put a cover on it for the winter but I'm encouraged by what I saw today so I'll order the gauges and do another plug chop and see how things go. Thanks man.
 
Thanks for that offer Solar. I just ordered a 4 gauge tool because of the progress I saw today. It's something that I'm sure I'll use again anyways since I would like to get rid of the 4-4 exhaust and run a custom 4-1. At this point, I at least think it's safe to ride it since I'm not dropping cylinders anymore.
 
Bit of an update:

I finally got my vacuum sync gauges and got time to fool around with them. When I bench synced the carbs, they were adjusted so that once on the bike the idle screw was backed out so far that it did nothing in either direction and the idle was too high (about 2200). So before I went about syncing the carbs, I wanted to lower that idle and make it so the idle screw would actually function. So what I did was I loosened all of the sync adjusters, started the bike up, and turned each one in half a turn. This lowered the idle and I blipped the throttle. It wasn't quite low enough so I went another half a turn. Now the idle was down to 1200 and I could use the screw to bring it back up to about 1600 and have room for adjustments up or down. I then synced the carbs and decided to take it for a spin. Cylinders 1 and 4 ended up dropping and I got stranded (bike died) until I could get it going again and limp it home. When I pulled the plugs, they were all nasty black and 4 was back to being wet with fuel. Some guys on the Honda forum are saying it's a coil that went out or is working intermittently. I disagree and I verified that I still have good spark doing from the coils at the end of each wire. I think if plugs 2/3 looked like they did the other day when I chopped them (nice and tan), I'd buy that. But since all 4 were wasted (rich and fouled) I think that lowering the slides in each carb to fix that high idle was enough to **** up the A/F ratio again and now those 95 mains are too big. Am I thinking correctly?

I'm just a bit amazed that with all of the discussions regarding carb tuning on CB forums that altitude never is brought up. I guess for most guys that are into these bikes it's not much of an issue (California, Texas, etc.) but when I specifically say that I live at 9000' I still hear that that will not play a part and basic math says it most definitely will.

My plan now was to get more plugs, throw a fresh set in and chop them up here again and see if they're fat. If they are, then I'll throw the 90 mains back in and do it again. Does this sound reasonable? A vacuum sync alone wouldn't cause that rich condition but that's not all that was really done. Sorry for the novel.
 
I don't have a ton of carb experience, mostly model airplanes and lawn mowers, but everything I've ever been taught was that you established the low speed mixture before you adjusted the high speed mixture. Rather than skipping around a lot, I would start at the very beginning of whatever manual procedure there is and make sure every step of tuning is correct before you get to the next one.

You might end up with different jets, etc, but you just saw how important it is to follow the tuning procedure in order.
 
Hey Redheep, everything I've read for these motors says to start with the main jet first and do plug chops at WOT. Next step would be to look at mixture screws.
 
riverfever said:
Hey Redheep, everything I've read for these motors says to start with the main jet first and do plug chops at WOT. Next step would be to look at mixture screws.
Click to expand...


Is that per forums or per repair manual for that bike?
 
I have 2 factory manuals and neither really go into detail about carb tuning so what information I have gathered is via forums and friends that I trust who have successfully tuned multiple bikes.

Redheep...I am able to open that first link but not the second one.
 
I use NGK D7EA plugs and stopped at Apex on the way home to grab some. They only had 4 so I also grabbed DR7EA plugs (these have a resistor in them but should burn the same). I installed the DR's first and went and did a plug chop at the same speed, rpm, altitude, and at the same spot as I have multiple times before. This time the plugs were dangerously lean (for 1 and 2). I went back home and installed the D7EA's thinking I should just have everything the same and did another chop. Exact same results this time. Super lean. I see no reason for a chop a few weeks ago with 95 mains, same plugs, and same location, speed, etc. to now be on the lean side all of a sudden (the only change being a vacuum sync). I guess tomorrow I'll throw the 100 main jets back in and see what the plugs look like. I'm very frustrated at this point. Hell, just the other day when I got stranded, the plugs were so rich they fouled out. Makes no sense to me.
 
What are they basing the need for that jet size on though? What are the variables like altitude, stock air box or pods, stock exhaust or aftermarket? Also some of the carbs on the 550 do have one that all the others need to be set to but on the old 500 carbs (model 627b) all 4 carbs are adjustable so when syncing them you're really just picking one and then adjusting the other three to be of equal value.
 
And stock main jets are 100 but I have tried 90s and that was way lean. 95s were good one week and then lean yesterday. Tonight I'll reinstall 100s and ride it again.
 
River i talked to a friend who has been a m/c mech for ever ( 50) years at leasy he said call him maybe he can help Norm Belther 909 886 7667,,so call him and explain you issues ,
 
I feel like all I do is change plugs and check them. I installed 100 main jets AGAIN and reinstalled fresh plugs and chopped them up here. 1 and 2 look better than yesterday. 3 is a bit more rich and good old number 4 is it's usual Donald Trump self. I have come to the conclusion that there are simply other issues that need to be addressed/fixed before this thing will run properly (like a top end rebuild). The issues in the motor (valves, guides, seals, crappy rings) are just making it impossible for one jet size to cover all the cylinders. There is a part of me that thinks, "Oh this is just not a bike that's going to be able to run properly up here" but then I think **** that...once it's rebuilt I can tune it to run at damn near any altitude. I think I'm at the point where I'm gonna run it the rest of the summer (at least up here) and if it blows, it blows. Then I may be at the point this fall where I take it off the road for a long rebuild.

Thanks Jim. I'll PM you.
 
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