UPGRADING MY GL1200 IGNITION SYSTEM

[sparky65]

No updates yet. My bike is down for tire installation, cosmetic touches, carb rebuilding and fine tuning. Will give a road test report once she's up and running again.

Reading your original post where you said spiders in the water drain holes near the sparkplugs just reminded me to check mine soon. On my previous bike a GL1100 it was missing and backfiring now and then. Water was sitting next to a plug. I think I used a chainsaw file poked the drain hole and cleared the drain of pine needle and grunge. Plugs don't like to sit in water. A simple thing worth checking now and then.It cured the miss and backfire.

[wingandaprayer]

We call that CRS, Can't Remember Shit

ha ha ha ha ha

I know this condition ...

[sparky65]

We call that CRS, Can't Remember Shit

ha ha ha ha ha

I know this condition ...

Maybe I'll get a hat with my name on it and a belt buckle the same like my friend BOB so on a bad day I can just look down or in the mirror if I forget who I am. BTW I hinted to BOB I was going to swipe his hat and wear it to confuse him cuz my name happens to be BOB as well. ha ha

[admin]

UPDATE: while inspecting my bike last night I noticed that the choke was staying on partially which would explain why it would start when cold without setting the choke. It seems that since the bike was sitting without running since last August the enricher valves had seized at about 3/4 open on carbs 3 and 4 which resulted in carbs 1 and 2 staying open partially as well. Got them all freed up and working properly and now the bike will start and run very rough when cold without the choke, but, runs much better with the choke on when cold which is about right. Earlier I had thought the coils only had made all the difference when starting cold, but, it seems that it was the choke malfunction that made the biggest difference, although the coils were able to keep firing the plugs in spite of the rich mixture when the engine was warmed up fully. I do plan on increasing the main and pilot jets one size and adding 2 washers under the needles to see what, if any, difference that makes to performance and drivability, as typically GL1200's are jetted on the lean side to decrease emissions. More to come after I do some road testing.

[Frank]

I'll be getting into the carbs on my 85 in the next few weeks so I'm really interested in how this turns out. I can do a set of 4 on a DOHC CB750 blindfolded. On my CV carbs I went from 68/102's to 75/110's, no washers. I bi-passed the air cut off valves (4) and increased my fuel mixture screw to 3 1/4 out from lightly seated. I increased the air flow by going to a Uni foam filter. Although changing exhaust is supposed to have little effect on the performance of CV carbs I was running shorty mufflers so I really can't confirm or deny if it had any effect on the operation. I'm not too big of a fan of shimming needles, always afraid that they will bind I would rather just go up in jet sizes. I'll be cleaning my carbs in Pine Sol, like I do all my carbs, so I'll document it as I go and post all of my results. Using the Pine Sol I won't have to break the individual carbs off of the bank, just remove most of the easily gotten to items so the solution can get in there and I can clean the emulsifer tubes and run piano wire through all the small jet passages. I just did a set of 4 on an 85 Honda VF500 Magna and they came out great. The only carb parts I have ever had to buy to do a rebuild have been maybe some new float valves and replace a few old o-rings, everything else I just clean up and reuse. If I get a leak on any of the carb bowls I use 3-Bond (1194?) just a VERY thin layer, fuel doesn't effect it and the bowl can easily be removed later if need be. It idles just a little rich but anything off of idle and it runs like a scalded dog. Plugs have almost a white color so that tells me they are almost peak without running too lean.

http://forums.commonbiker.com/post/Carb-...0C-6348623

[Frank]

Are you going to bi-pass the air cutoff valve?

[admin]

If I did bypass the air cut off valve I would be causing myself some serious problems as its function is critical to good performance when the throttle is snapped shut then opened again. So, to answer your question directly, no, I will not bypass the cut off valve.

[Frank]

That is a misconception. I'll be bi-passing mine. Was just curious

[PanMan75]

Vic any road testing done?

[admin]

Haven't had much time to ride so far, but, in the 200 kilometers I've put on to this point I am very impressed by the quick starting of the engine, cold and hot, and it appears that when lugging the engine (I know I shouldn't do that) it does not shudder and shake as much as before which means that the fire must be getting lit much better than with the stock ignition coils. I am very anxious to run the bike through a very heavy downpour (well, not really) to see if the engine will miss and sputter when wet like it used to do with the stock coils and wires (which were almost new and the spark plug drain holes were clear.) To this point I am convinced that these Accel coils and wires are a good addition to my bike, but, it will take a long term test to prove that out.

[admin]

That is a misconception. I'll be bi-passing mine. Was just curious

Hi Frank, just wondering if you are fully aware of the precise function of the air cut off valve and how it affects the engine's performance? It serves a very critical function in the operation of our bikes.

[Frank]

Yes I am Vic. I have even had some extended discussions with Mike Nixon from the Motorcycle Project about it. There is nothing wrong with leaving it if it is in good shape and functioning properly but then again it can be removed without any compromise in performance or function.
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http://www.motorcycleproject.com/motorcy..._paper.swf

[admin]

Yes I am Vic. I have even had some extended discussions with Mike Nixon from the Motorcycle Project about it. There is nothing wrong with leaving it if it is in good shape and functioning properly but then again it can be removed without any compromise in performance or function.
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http://www.motorcycleproject.com/motorcy..._paper.swf

Thanks for the reply Frank. Somehow it seems that you and Mike Nixon have a totally different view on the function of the air cut off valve and that's OK if it works for you, but, I haven't seen a GL1200 that runs properly without a fully functional air cut off valve. I have seen some GL1200's that ran, with quirks, without the air cut off valve and an air cut off valve that worked intermittently, but, those bikes just did not feel like they were running up to par, as far as I was concerned. Perhaps if a GL1200 was jetted way too far on the rich side then, in that case, removing the air cut off valve might possibly work I'm guessing, but, it would make more sense to install the air cut off valve, jet the carbs properly and gain more performance and fuel economy, but, I certainly don't and cannot know everything. Regarding the link in your post, Mike Nixon should also clean up a stated discrepancy, on his site, pertaining to cleaning brass jets with steel wire. If one were to round the end of the steel cleaning wire and push it through the jets there would be no issue, but, if one would cut off a piece of steel wire with regular side cutters, diagonals or the like they would create a razor sharp edge on the wire that could leave a scratch on the inside of the jet's orifice which could severely affect the rate of flow going through the jet which may translate to a richer or leaner mixture which may affect drivability and become an issue that would be extremely hard to diagnose. We all make errors in communicating our acquired knowledge when we share it on the internet, so, I hope that you and Mike Nixon are not offended by my difference in perception. I just want GL1200's to run as best as they can for as long as they can and that is precisely why I created this forum, many years ago, to help guys and gals who are lacking in GL1200 knowledge to get their Wings running great and properly without having to spend a fortune at a shop that doesn't really give a damn about our precious GL1200's.

[Frank]

Oh hell no Vic, if we all agreed on everything it would be a pretty dull world. I enjoy a good discussion about almost anything. I do a lot of things that are out of the box, maybe I heard it somewhere, maybe I read about it and sometimes I just have theory's that I have worked up or calculated out. I wasn't really out to create a discussion on the subject I was just curious if it was something that you had heard about and were going to be doing while you had your carbs off. The emissions controls brought about several changes that motor manufactures had to deal with. Crankcase blow by gases, fuel gas canisters, catch tanks.....and lean conditions for carbs. My experience with air cut offs has has lead me to bi-pass them (and jet up) then tune for a rich condition at idle. Anything off of idle and it leans back out yet provides plenty of fuel for a slight performance increase. I have gotten a hold of some documents by Honda Racing, put out in the early 80's, that shows the steps that they went through to tune CV carbs and one of those steps was to bi-pass the air cuts. I understand in your position that you can do little more than endorse a stock set-up. Too many things can go wrong when the general public tries to do anything out of the box and then that just creates even more problems. As you know I often share my out of the box projects and I then share the results, sometimes they are good and sometimes, well.....not so good, ha

I do find it interesting though that you dismiss my thoughts on the air cut offs yet made this statement: I do plan on increasing the main and pilot jets one size and adding 2 washers under the needles to see what, if any, difference that makes to performance and drivability, as typically GL1200's are jetted on the lean side to decrease emissions.

We both are attacking the same problem just in different ways. I'm not a big fan of shimming needles since most of the time that is done with a Dyno Jet kit and I'm not a big fan of Dyno Jet, ha I haven't found very many people that had better luck with them than if they had just selected some different jets. It's hard to tell what sizes they are since they use their own sizing system. I really am curious as to what you might do and the outcome.

[admin]

In the past I have done a lot of drag racing and street tuning and I have first hand dynamometer tuning experience with air/fuel ratio meters along with exhaust gas temp analyzers so I have picked up a thing or two along the way that has helped me to tweak an engine and gain better overall performance. Many times I have seen seat of the pants tuning or bench racing tuning to be way off base whereas dyno tuning with proper analysis equipment will yield far more accurate or more clearly seen results and, ultimately, quarter mile times are the most accurate means to determine if tuning results are a positive or a negative. Although ultimate performance and superior drivability don't always go hand in hand. So to address my comment regarding, "increasing the main and pilot jets one size and adding 2 washers under the needles to see what, if any, difference that makes to performance and drivability, as typically GL1200's are jetted on the lean side to decrease emissions" is just a starting base to meet the operational changes that my engine has incurred since I upped the ignition spark output with the addition of the new and improved coils and plug wires. The jetting may be perfect as it stands right now, but, the increased jet sizing may yield a greater or decreased power output and I really won't know until I try. The washers under the needle clips may help midrange throttle response, but, it could make it worse. Carb tuning is quite possibly the very most terribly understood technology because it more of an art than a science and it requires a lot of diligent patience and expertise to finally make them run their very best. I have seen far too many guys tune their carbs only to have their bikes make more noise but less power output and these guys thought that more noise meant more power. In my case if I do not perceive any appreciable seat of the pants performance improvement after the jetting recalibration I will head for the dyno and meters to see what is really happening with the power output and the results may tell me to go richer with the jetting or leaner to obtain best overall power output. All this must seem silly to the average GL1200 owner because as long as their bikes starts, idles and runs fine then everything is perfect, whereas, I am always looking for that last 100th of a second off the quarter mile time or a plus number on the dynamometer. If my carb tuning doesn't work out then I might lean towards the fuel injection and turbocharger in my garage attic and at that point I can then engage in a full time hobby that will consume all my time and money, but, at least it will be a lot of fun until my engine dies and I am forced to install my spare engine with the ported and polished heads. I guess I'm dreaming in color at this time because my wife wants our house renovated first and, besides, she just doesn't understand the need for a fuel injection system and a turbocharger on a bike that already scares the hell out of her when I turn the wick up all the way, but, she just doesn't understand what it feels like to own a fully adjustable, home built (with my own hands) custom fuel injector controller and I have, in my garage attic, a complete fuel injection system with a turbo ready to attach to my GL1200. I better stop now because I am starting to drool just thinking about how that engine would sound and run with those custom components on it. Back to reality, for now, I will post when I make the changes to the tuning of my bike's carbs and I will then share any performance improvements or detriments so others may benefit and learn from my experience and no, I do not recommend disabling the air cut off valve on a street driven GL1200 unless you are racing because you would then be creating more problems than benefits and the bike would not be running at its best especially if you richened the jets to compensate for the ill effects. Hopefully you'll be coming to our site's Sudbury meet in August so we can discuss in person. See you there if you make it out.