Carb spring question?? Sync question??
 

We're trying to get Steve29's (who started Disabled PAIR thread)bike sorted out and yesterday removed the carbs to remove air mix screws and slot them for easy adjustment. We also took carbs apart to ascertain jet sizes and needle settings. In the process of pulling the tops off the carbs, I was surprised that the caps did not push out when the screws were removed. The springs were different from OEM because when we reinstalled the caps, we just dropped the springs and put the cap on without the normal having to stuff the spring up the tube and carefully insert when putting the cap on. My question is, could this weak/short spring affect performance?

He doesn't know where or how these springs came to be other than they may have been part of the Dyno Jet Kit. Is this possible that they would include such a wimpy spring with their kit?

Sync question: when syncing with the quick sync set up (where you add the fitting and short length of tubing to the front carb and T into the rear carb/vacuum lin to the tank), do you disconnect the vacuum line and plug it or leave it in-line. It seems that to make sure that the sync is equalized, that the vacuum going from the tank to the rear carb should be separated from rear carbs so the you have equal lengths of tubing from each carb. The problem with plugging off the vacuum line going to the tank is that the engine shuts off after several minutes of idling. What is the proper method because i have done it both ways?

well steve29 got the answer for the carb spring question. Honda's killer spring is an unnecessary nuisance given that the Dynojet wimpy ass spring works better?

Still no answer on the carb sync questions.

Maybe I'm overlooking something here, but I really can't see that it would make much of a difference by leaving the tank petcock connected or having slightly unequal length lines. Once the engine has run a moment and the rpm has settled down, the vacuum should be fairly constant (it pulses with the piston movement anyway, of course). And your sync tool doesn't show a perfectly steady reading either.

It's not like setting valve clearances, where you can fiddle a thousandth here or there till you get it right. You're going to have to settle for some approximation in the vacuum levels -- getting it "close enough." I think any differences caused by the line lengths or the petcock draw would fall within the jiggling of the readings anyway.

But I'll be the first to admit that I may be missing something.

length of the hoses has no relevance and neither does the petcock hose staying connected. I always connect up to my t-fitting and leave the end connected to the petcock that way my gas stays on will sync. If you think about it the system is under negative pressure given enough time you could hook your bike up to a huge compressor tank and it would still read the same. If you are worried about it still you can take a pair of vice grips and a few deep sockets to make a poor mans hose clamp, then start the bike pinch the petcock vacuum line off and continue with the sync, but IMO thats extra work.

oh and as far as the dyno jet spring is concerned they have you drill an extra hole in the slide to compensate for the shorter spring. So in the end it works basically same or at least in my experience no noticeable difference over, except for easier assembly.

I agree with cornandp -- with the short springs and drilled slides, the carbs will work fine.

When I bought my '02 SH, it had Muzzy cans on it. The seller had no idea whether the carbs had been jetted. When I swapped back to the stock mufflers (got them with the bike) I took the carbs apart. Inside were the light springs, drilled slides and DJ needles.

I put it back together with stock jetting (per Greg's suggestion) and the DJ needles/drilled slides -- it runs fine through the rpm range, very rarely pops back through the exhaust, gets average gas mileage and has a decent idle. No complaints.

I love the dog, aren't they great.

Since we got steve29s bike running the best ever yesterday afternoon, so good he chose not to accept my offer to sync the carbs. Given that the bike is running perfectly, I am witness to the fact that the short light, spring works well.

My questions are valid , however spurred by a lack of understanding, not only about how each component works, but how everything functions together. When I look at the airbox, the carbs, velocity stacks, hoses, cables, wires,etc, I am humbled and even aghast at how Honda or anyone else could ever have figured all this mind boggling shit out, manufactured it to miniscule tolerances, and have it all work together. Now i certainly know that that this was a process of evolution over time, starting with relatively simple contraptions and slowly maturing into what we are riding today, but this still blows my mind and I have never taken it for granted, and this respect requires me work on them with the care of an artisan or physician,or maybe even a brain surgeon.

As I mentioned to Steve during our days of working on his bike, There's only a relatively few mechanics who really have a thorough understanding of how the whole vehicle, whether it be a truck, motorcycle or other, functions as a whole,that is how one system affects another, from the suspension, to engine components, to the electrical. I have been fortunate enough to work with one such person whom I assisted for 6 weeks in the process of modifying my tractor(84'Autoar I bought new and put 1.6 million miles on) to accept a large sleeper. These unique individuals are somehow able to so thoroughly understand not only how each system works internally, but also how they all work with each other. The majority of mechanics are more like me in that they become familiar through repitition and, even though very skilled through experience, can never achieve this level of insight. We lesser beings merely take things off and replace them, dismantle and rebuild, but cannot ever seem to reach Nirvana or enlightenment.

Thus my second question regarding the length of the vacuum lines, the one I cut going between the rear carb base and the petcock, and the added line from under the front carb. Given my lack of understanding described above, I was following what i read on this forum citing that the lines needed to be the same length which precipitated my question about how that would be affected by leaving the vacuum line hooked up to the tank(rear carb line would be long and front carb would be short). But you guys obviously understand what I don't. When I isolate and plug the line to the tank, and use only the two equal length tubes from the carb bases, the engine shuts off after a short period. My rational for this was that it was loading up or something similar and this was causing it to shut off, while what is really happening is that it is simply running out of fuel. Thanks for clearing up the fog on this and many other issues so that we unenlightened take off and replace mechanics don't have to totally rely on the trial and error method to keeps these Hawk running. Thanks, Nathan

If you like, you can hook a mitey vac to the petcock and pull pressure on it to keep the fuel running, then sinc as you will.

See what I mean about understanding things. Thanks. The question is, is there any advantage for sync to have equal length lines, because accord to Corn's earlier post, it don't make a shit for equalization of carbs? Corn's probably right, so my efforts to equalize everything is just another exercise in futility.hahaha No advantage unless you're OCD, huh.

The length of your hoses does not matter.... The hose does not "use" vacum nor does the pitcock....it has a diapham in it... once it pulls it open (starts the bike) your not looseing any vacum pressure becasuse there is no hole in it. If you have a 50ft hose and put 40hg of vacum on one side.... once the pressure equalizes you'll have 40hg of vacum on the other end. Your gauge doesnt use any either..... its a sealed system.

In this case your only loss of vacum (your hole) is your thottle bodies. What your doing is making your loss of vacum the same amount in both intakes.... by making the exact same size holes ..... aka ...by adjusting your throttle plates

yeah, I guess the best way to sum it up is you are measuring the negative pressure not the flow, since like superman said it is a closed system.

sounds good to me. That makes it easy, just unplug the Ts and hook up the hoses. I have a self made tool that works well since I put wd40 spray tubes in the fish tank hose ends to slow the up and down oil response. Makes it alot easier to adjust before you suck oil into one of the carb holes. ah oh! That's how I do shit, alot of Trial and Error and a little bit of brain.hahaha

thanks for the assistance and the education attempts, but with all due respect, i might require remedial special education services to help me "comprehende". Some people think in pictures, some words, but i need all that and to have my hands involved with alot of repitition before I begin to understand. maybe that's why I've been riding for 45 years and I'm still doing stupid shit and falling off.hahaha

I know one thing for sure. I took me but one ride on the SH to know that the 1000 hurricane I bought new 2 years earlier had to go, so maybe I'm not as dumb as i look, huh.

Must be that extra heavy atmosphere on Krypton...

Have you ever looked under the hood of a 1980's carbureted Civic with the CVCC engine? There are about a gazillion vacuum hoses, many of which feed in and out of a plastic box. Removing the cover of the plastic box reveals a ton of vacuum solenoids, all of which are necessary to meet emission requirements. Then there's the dual float bowl, 3 barrel Kehin carb feeding both the stratified and main combustion chambers....Very clever, those Japanese.

Hey nate. If you wanna try a sync next week we can, then go for s ride. Putting it on the dyno on the 7th. Guess we will know if I'm too rich then. The guy seemed shocked when I told him we set the needles on the 6th groove. I have s feeling based on what some others have said that I'm gonna be rich at wider throttle openings. So maybe I'll have to step down the mains. We shall see...

yeah sure. let me know. we can pull the plugs and check too.

No I haven't, but I'm in awe of the simple stuff so i can't imagine. Who are these genius' that can determine how all this shit works, huh. I'm glad they're able to do it.

I always thought that too and was really confused when I read this:

From what I've read, Kai Ju really knows his stuff, but I couldn't get that to make sense to me. Carb syncing this weekend, so I guess I'll find out.

I wouldn't be able to clear that up definitively other than I have equal length tubes, but I synced them both ways: i.e.,with the vac line to the tank capped off(then you run out of gas within a few minutes), and with it hooked up and this essentially gives you different length tubes. It didn't seem to change the setting. Next week we'll be doing Steve29s again, so i'll do it both ways again to verify. But if you're doing the sync this weekend, you can do the test and let me know. huh. Do you have a store-bought sync tool or did you make one?

I made one and I think I'm going to intentionally shorten one side of the manometer and see what happens. This would lengthen one carb's tube just the same.

i don't know if you read it but mine is tubing mounted in a U-shape and held on with wire tacks. About 3" high. I drew some lines across at the approximate oil level with a permanant marker just for a reference.

The thing i wanted to mention was that when I tried to sync the oil would move so fast that i had to shut the engine off a couple times until i had an idea that works well. I cut pieces of a WD40 spray tube and inserted one in each end of the tubing and it. With the aquarium tubing i used, it is a tight fit so they don't move. These inserts mitigate the flow speed so that you have plenty of time to adjust. I have one of those bendable gizmos with a little socket on the end but I had to have Steve hold the throttle forward while i adjusted. Have fun.

Life kept getting in the way, but I finally got to sync the carbs. Homemade manometer worked great! After syncing, I shortened one tube and didn't notice any change. Like you guys love to say, YMMV.

glad to hear it worked out. Any problems, techniques, or thoughts on the sync. Did you baffle the tubing, hold the throttle forward when you were adjusting? Did you have to change your idle?

MityVac - sounds like a super hero with amazing sucking powers. That would make a good movie or comic book.

No problems really. I rode it around to get it warm, raised the front of the tank just to make it easier, hooked up the gauge, and synced. I didn't have to hold the throttle, though it was hard to keep from pressing on the screw when trying to turn it. I did blip the throttle here and there to make sure it settled back to the same level. I did baffle the tubes. It slowed the rate of change to the fluid levels when making corrections. Once synced, I did have to turn my idle down a little. I used ATF for the fluid. Maybe something a lil thicker would be better.

Or girlfriend.

Lol!!