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Ken Tarver
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« on: May 28, 2009, 01:55:56 PM » |
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Dag, made a copy of your 6 gauge sync tool.
Attempted to balance 1, 5, 2, 4, 6 to match 3, which was drawing 15 in/Hg.
Bike ran like crap and fuel mileage was extremely bad.
A few days later I saw post by fudgie and you about the sync numbers, stating 8 in/Hg was normal.
So I re-synced 1, 5, 2, 4, 6 to 8 in/Hg, the #3 still has a 15 in/Hg.
So is this the correct result? 5 of the intakes having 8 in/Hg and the #3 has 15 in/Hg
The bike does idle and run very well now, and the mileage on a quick trip to Nashville and back averaged 38.5 mpg with a combination of freeway and secondary roads.
Bike is de-smogged, 6* trigger wheel, stock pipes.
Thanks Guys
Ken
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Dag
Member
Posts: 1779
I have a love affair with a bumblebee
Country Rep. Norway
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« Reply #1 on: May 28, 2009, 03:07:54 PM » |
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When looking at my video you can see its between 8 in/Hg I have not found that written anywhere, but mine runs smooth as silk.
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The question is not what you look at...but what you see...
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fudgie
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Posts: 10613
Better to be judged by 12, then carried by 6.
Huntington Indiana
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« Reply #2 on: May 28, 2009, 07:10:58 PM » |
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Huh, a 15 in/hg. Interesting. Well if it runs alot better then I saw your good. Check the plugs a run or 2 later and see how they are. If all is good then run it! I wish I got 38 mpg!
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 Now you're in the world of the wolves... And we welcome all you sheep... VRCC-#7196 VRCCDS-#0175 DTR PGR |
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Ken Tarver
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« Reply #3 on: May 28, 2009, 10:08:55 PM » |
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Yes sir, I see your video Dag....and have also seen it before. ALL of your gauges are pulling 8 in Hg. I did look in the shop manual for a specification indicating 8 in/Hg. I didn't find any reference to it, so, if you don't mind the question, how did you come up with that? Was it experimental trial and error? At the start up of my sync process, the #3 was reading in the range of 15 in/Hg. ALL the way through the adjustments of the other carbs, the #3 continued to stay somewhat close to 15, with some swing in the reading as adjustments were made on each of the other carbs. When I got all of the other 5 carbs at a reading of 8 in Hg, the number 3 CONTINUED to pull 15 in/Hg. Am I missing something? Or is there a problem somewhere causing the # 3 to be at 15 in/Hg? Has anyone else using 6 gauges had a similar result? By the way, I did check each gauge, one at time on #3 to see if they were calibrated the same, they are. Fudgie, yes it did run very well!! And the three tanks I ran to N'ville and back were 38.3mpg, 38.9mpg, 38.4mpg, for an average of 38.5 I've never before got that consistency in mpg in back to back fill-ups. THANKS guys for all your input and knowledge, this is THE place to go for information on the Valk! Ken  |
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Madmike
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« Reply #4 on: May 28, 2009, 11:21:45 PM » |
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My understanding of carburetor synchronization is that you are not trying to achieve any given amount of vacuum but rather trying to get them all pulling the same so that the butterflies or slides are all in the same position and and hopefully then will be in the same position if you move the throttle control throughout it's range of motion. What you are actually looking for is zero ¨differential¨ when comparing the carb(s) with adjustable control linkage against the master carb which has linkage that cannot be adjusted.
If you hook a slack tube manometer - similar to the 6 tube manometers that several fellows have made and posted here on this board - between #3 and any other carb, #3 will pull on one side of teh column of oil (or mercury) and raise the level to a certain height, the other carb will pull on the oil in the other side of the tube and raise it to a height. You then adjust the adjustable linkage so that the oil is at the same height in both sides of the tube, these carbs are now balanced or synchronized.
The spec for satisfactory synchronization is that the vacuum between each carb and #3 be within 40MM of Hg as per page 3-10 of the Honda service manual.
Have you had your carbs off the engine and separated??
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MP
Member
Posts: 5532
1997 Std Valkyrie and 2001 red/blk I/S w/sidecar
North Dakota
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« Reply #5 on: May 29, 2009, 04:00:01 AM » |
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Man, if it runs good, and you get that kind of mileage, leave it alone!
MP
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Ken Tarver
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« Reply #6 on: May 29, 2009, 04:34:52 AM » |
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yup madmike.....that was my goal in the post at the top of this stream. I wasn't concerned with the specific reading of any gauge; was just adjusting #1, 5, 2, 4, & 6 to match #3.
As a result, bike ran crappy and mileage went to hell.
Later re-adjusted #1, 5, 2, 4, & 6 to a vacuum of 8 in Hg as suggested by some other folks days ago, the # 3 remains at 15 in Hg.
Bike now runs super, mpg is good & consistent. I was just wondering why the difference in #3 staying at 15 while the others are balanced at 8, and the bike runs better than ever.
By the way, I have used a manometer, to me, the gauges are simpler and easier to work with.
Ken
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Dag
Member
Posts: 1779
I have a love affair with a bumblebee
Country Rep. Norway
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« Reply #7 on: May 29, 2009, 05:21:11 AM » |
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It sounds strange to me... Have you checked the #3 gauge? It could be somthing wrong with it.
#1, 5, 2, 4, & 6 to a vacuum of 8 in Hg and the # 3 remains at 15 in Hg don`t sound right to me.
The problem could also be if anything else that's out will throw out the vacuum each cylinder is pulling.
Have you checked the valve clearances?
You did the sync at 8 - 900 RPM?
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Ken Tarver
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« Reply #8 on: May 29, 2009, 06:01:24 AM » |
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Before starting, I checked each gauge to see if they all read the same using the same source of vacuum, the #3 intake. One (1) gauge was out of range with the other 5, so took it back to store and exchanged for another gauge, it checked out ok and read the same as the other 5. But I will re-check them.
Valve clearance has been checked.
900 rpm....yes, and adjusted rpm as needed between each adjustment of carb.
Oh yeah, Madmike, have not had the carb bank off and separated.
Ken
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Madmike
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« Reply #9 on: May 30, 2009, 09:20:41 PM » |
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Does the vacuum on the #3 gauge show a change if you vary the throttle??
If you have an infrared heat gun it may be interesting to see what the temperature difference is between #3 and the other cylinders right at the exhaust header where it meets the head.
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Patrick
Member
Posts: 15433
VRCC 4474
Largo Florida
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« Reply #10 on: May 31, 2009, 06:09:36 AM » |
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I can't tell from the posts what is really wrong,,but,, it appears that there is.. The only spec Honda gives is 1.6 in/hg difference between cylinders.. Most stock bikes will pull 16-18 in/hg at idle..A bike with valve timing changes will be different.. I guess my main question would be,, how much twisting did you have to do?? It really shouldn't take much at all [twisting/turning] to adjust these carburetors.. It appears that you now have 5 cylinders that are in sync with each other and only #3 that is different, so the engine probably does run smooth.. 38 MPG is acceptable,but, fuel mileage is really subjective, as everyones right hand works/twists differently..How about humoring me and trying this the old fashioned way by using just one of the gauges..Attach tubing to each cylinder , plug the free ends, and run them to a convenient location. Then take your readings from each cylinder, one at a time, ensuring that the free tubes are plugged and not drawing air.. The engine can stay running when switching tubes as the vacuum leak while changing tubes will not bother anything..
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Madmike
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« Reply #11 on: May 31, 2009, 09:19:03 AM » |
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I can't tell from the posts what is really wrong,,but,, it appears that there is.. The only spec Honda gives is 1.6 in/hg difference between cylinders.. Most stock bikes will pull 16-18 in/hg at idle..A bike with valve timing changes will be different.... I think you are correct............. What I am wondering is if #3 is controlling the closed position of the other carbs - It is closed and the others are slightly more open. If this is the case then is the engine idle being set with that relationship rather than the idle speed setting control?? I guess that this could be verified by backing out the idle adjustment with the engine running and see if the idle speed drops off or not - will the idle drop off until the engine stalls? I don't understand how running a 6 cylinder engine with 5 balanced cylinders will make it outperform having all 6 cylinders balanced. |
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« Last Edit: May 31, 2009, 09:38:40 AM by Madmike »
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Ken Tarver
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« Reply #12 on: June 03, 2009, 05:21:50 PM » |
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Hey Guys I guess you think I dropped off the face of the earth, as I haven't been back to the last few post from you. I got busy with other stuff and didn't get a chance right away to re-check stuff. To Dag.....I re-checked EACH of the 6 gauges separately, each one pulls the same vacuum when tested on the same source of vacuum. So all the gauges are good. I haven't got to it yet, but will re-check the valve clearance soon. It was checked about a year ago. To Patrick.....ok, as a reminder, I got good performance from the bike using all 6 gauges. Intake #'s 1, 5, 2, 4, 6 at 8 in. Hg & #3 at a constant 15 in. Hg So I then tried as you suggested using just ONE gauge to check each of the 6 intakes, for a comparison to the sync readings when all 6 gauges were used. here are the results using one gauge: #2 8 in. Hg #1 8.5 in. Hg #4 8 in. Hg #3 15 in. Hg #6 7.5 in Hg #5 9 in. Hg As you see, using the one gauge is close to the same readings as when using all 6 gauges. I did not re-adjust any of the carbs using the one gauge, only making a comparison. To Madmike....the number 3 does have needle fluctuation when the throttle is twisted; the other 5 do also. Sync was done at 900 rpm....adjusted as needed between carb adjustments. Waited for fan to cycle off before adjustments. Will also be soon checking for O-ring leakage. thanks folks.....your suggestions and assistance is appreciated Ken  |
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Madmike
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« Reply #13 on: June 03, 2009, 06:57:35 PM » |
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Have you had the air filter out of this?? Any chance ther eis something obstructing the inlet to #3 from the air filter housing??
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Ken Tarver
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« Reply #14 on: June 04, 2009, 08:23:05 AM » |
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Madmike
haven't had the filter out lately, but is time for a change, so will check the intake out for any blockage
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Ricky-D
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« Reply #15 on: June 04, 2009, 09:59:36 AM » |
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Having the five cylinders somewhat matching and the #3 cylinder almost double that of the others says to me that #3 cylinder is doing most of the work at idle. The other cylinders are just doing a small part.
In regard to the issue of better or worse running resulting from synchronizing (good or bad) the easiest way is to index your throttle.
That way you can actually see what the throttle setting is when cruising.
You will find that at cruise speed the throttle is at least 1/8 to 1/4 open. The motor is virtually off the idle circuit and only partially benefiting from the low speed jet and the is coming on the intermediate circuit and slide needle.
The point I'm trying to make, is that at those throttle settings, synchronization has virtually no impact on the performance of the motor.
The slides are controlling the motor once you've cracked the throttle. The butterfly(s) is what you control when twisting the throttle. The "seat of the pants" dyno is a poor judge of performance and it usually reflects what we want the results to be. My bike always runs better after a wash job and really hauls ass after a intense detailing session.
I suggest turning the idle down to reduce the numbers on #3 and turn up the remaining five cylinders to achieve harmony. Idling will be much better and stronger and less subject to poor idling characteristics.
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2000_Valkyrie_Interstate
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Ken Tarver
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« Reply #16 on: June 07, 2009, 10:45:09 AM » |
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Ricky-D
thanks for tip on turning down the idle some to bring down the number on #3, then adjusting the others higher. I haven't got back to work on it yet, and it will be probably another week before I do.
I'll post the result.
Ken
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Kingbee
Member
Posts: 486
VRCC# 576
Northern Illinois
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« Reply #17 on: June 07, 2009, 01:11:37 PM » |
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Plain & simple rule of carb synch. All 6 cylinders should match - The specific Hg reading is unimportant, period. Once you crack the throttle, due to our carb linkages, the synch is out the window anyway.
Don't bother reminding me you shouldn't hold a movie cam sideways.  |
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