1978 GS1000 bored out to 1173 by RC Engineering

[Guest]

http://s88.photobucket.com/albums/k175/jpmason_2006/GS1000b/

As you can see, I've installed a new R/R. As you cannot see, I also installed a new stator. Also installed the familiar green Dyna coils and Dyna S ignition. The timing is dialed in. Got new intake manifold boots with nice stainless allen head fasteners, just waiting for the 29mm smoothbores, which are getting sorted out at Wired George's carburetor ranch in Texas.

Vance & Hines street megaphone is on the way. In the meantime, I'm gonna check the valve clearances and replace the paper gasket with the Real Gasket silicone version. When the carburetors arrive, I'll affix the K&N pods, synchronize and begin scaring myself, I hope, every time I whack the throttle.

Many thanks to the GS veterans who've provided so much useful instruction as I grope my way through this restoration.

More pictures when there's something to see.

Thanks,

Jack

[Tom MLC]

Nice work Jack. Your patience and attention to detail really comes through. Are you riding another bike while working on the hotrod? I got your PM. Gotta make it a point to ride up and see you.

[jimcor]

How's your battery? If I just did the R/R, Stator and ignition system I'd spring for a new battery too.

[Guest]

I'm guessing that with the pumped up motor I should select a number or two higher than the stock B8 on the NGK spark plug temperature scale. The bike came with B9's installed and a couple of packs of B10's in the spare parts bin the previous owner gave me. I'd be grateful for any advice from the drag racing drivers on this subject.

By the way, I installed the rebuilt carburetors this Sunday, screwed on the new K&N pods, installed the V&H four-into-one, put the gas tank back on, primed the carbs and thumbed the starter.

Ignition! Nice growl from the new pipes and steady idle at 1,000rpm! I didn't have a lot of time to test drive at multiple throttle settings, but the bike seemed eager to go. One fine-tuning question:

Should I keep the two carburetor vent holes with or without hoses? And what's the reasoning behind leaving them off when running pods?

I'll post pictures tomorrow. And thanks for the help.

Jack

[KEITH KRAUSE]

Remove the float bowl vent lines, leave the ports open. You'll likely experience fuel starvation if the lines stay on. Some bikes show fuel starvation more than others. Depends on mod's and how the engine flows. I really don't know how to explain it technically. Someone else may know how.
I've read a few opinions on what's happening and I have some of my own.
When going from a stock air box to pods, especially if you run a freer flowing exhaust, there's an obvious air flow increase. The float bowl venting ability differs in various carb types. Some designs are only adequate, while others have more venting ability and can vent adequately even if you go with pods.
With more air and fuel running through the carbs, the stock venting design can't keep up with the added demand and the result is poor venting and that makes it harder for the jets to draw fuel. Since you can't easily enlarge the venting passages/chamber, the best you can do to improve venting is to remove resistance by removing the line. To add, another opinion that was given to me from Dynojet was that a vortex actually forms in the line and that further inhibits adequate venting. Dynojet jet kits recommend to remove the lines, especially on bikes that are in California and/or used on freeways often.
Crosswinds also can effect pod/venting performance. While I'm no expert, I can see how crosswinds would effect the desired stream of air into the pods. No longer the desired stream, a turbulent/erratic flow of air is going to cause vacuum fluctuations and how easily/constant the fuel is drawn up from the bowl. If you add to this the compromised venting I mentioned above, you'll see fuel starvation, though it may be more severe from bike to bike. I've tested several bikes over the years and I don't hesitate to remove the lines anymore because I know what will happen. My '79 1000E with V&H pipe/K&N ovals was greatly effected. Very similar to when you first run out of fuel. I didn't believe it until I tested for myself. I see no problem with removing the lines as far as dirt/water/bugs entering. I've never read of a problem caused by dust/dirt or bugs entering. I can see where water could be a concern but have yet to hear of a problem related to rain. If you use a hose on your bike, just use common sense and don't point the hose right at an open vent.
I let people know about removing the vent lines several years ago and many have come back and said they were amazed that the reason for their "lean jetting problem" was really just poor bowl venting. The VM carbs appear to be effected more than the CV's but many CV carb owners said removing the lines gave a noticable improvement while some said they couldn't notice any difference. The vast majority of those that said there was no difference didn't have a noticable venting problem to begin with.
Your smoothbores are designed for an improved flow. How that factors into the venting/crosswinds opinions above I can't say exactly. It still varies from bike to bike. I can see where they may actually be effected even more than "regular" VM's. They may be effected less. I've assisted a couple owners in the past with their 29 smoothbores and the said they could feel surging that they thought was a lean condition and no richening of the pilot jets or jet needle position helped. After removing the lines, the surging went away. They did have a lean condition but it was from fuel starvation, not lean jetting.
Once in awhile someone shows up at this site and asks questions about smoothbores. I/we ask for them to tell the results of suggestions given here. Most of the time they get help and disappear. So for a lot of us here, our knowledge of smoothbores is limited compared with other carb designs.
I hope you'll share your results after doing some performance/plug read checks at various throttle positions.
You don't mention any vacuum synching of your carbs. They must be vacuum synched well to get accurate performance and plug reads. Before that, be sure your air screws are adjusted using the highest rpm method and your ignition timing is spot on, valve clearances correct too.

[txironhead]

Got new intake manifold boots with nice stainless allen head fasteners, just waiting for the 29mm smoothbores, which are getting sorted out at Wired George's carburetor ranch in Texas.
>>>>>
I'm gonna check the valve clearances and replace the paper gasket with the Real Gasket silicone version.

First, where is Wired George located? I'm in Texas and would like to check it out. Is there a website?

Second, where did you get the Real Gasket?

[Guest]

Thanks for your explanation, Keith. I will keep you posted and others who may be interested in 29mm smoothbores. They're new to me as well, and I'm interested in how they'll perform.

Snapped some photos this morning but I left the memory card at home. I'll get 'em posted when I return this evening.

For Txironhead, Real Gaskets is located in Tennessee, and their product is well regarded judging by what I've read on the GS Resources. Their website is realgaskets.com

As for Wired George, there is a wider range of opinion about him on this site, but from my experience, his rebuild work appears very meticulous, his carburetors function well and he seems to know his way around Japanese multicylinder bikes. His website is wgcarbs.com

Good luck.

Jack

[hp1000s]

To Keith's point....I read his vent tube findings in another post a long time back. I had what I thought was a lean surge: proceeded to richen and richen and richen, till it fouled plugs...still surging! Ditched the vent hoses, which were there when I got the bike years ago, put the carb settings back where they were when I started, and voila', no more surge...Thanks, Keith.
Hugh

[KEITH KRAUSE]

To Keith's point....I read his vent tube findings in another post a long time back. I had what I thought was a lean surge: proceeded to richen and richen and richen, till it fouled plugs...still surging! Ditched the vent hoses, which were there when I got the bike years ago, put the carb settings back where they were when I started, and voila', no more surge...Thanks, Keith.
Hugh

You're welcome.

[KEITH KRAUSE]

As for Wired George, there is a wider range of opinion about him on this site, but from my experience, his rebuild work appears very meticulous, his carburetors function well and he seems to know his way around Japanese multicylinder bikes.

I want to say something here that needs to be said. Sorry to momentarily change this threads subject.
I got into it with him a while back. I did not mean for the whole thing to get as serious as it did. But I take some things seriously enough to say what's on my mind and stay with it when I know I'm right.
Negative things typed will always stand out more than positives and I understand that and how things can escalade.
George seems to be very capable as you say. I said the same thing in the other thread. I have no doubt he can clean and rebuild carbs just fine. He SHOULD have a good idea of where to start if asked to re-jet but I've found some of his past re-jetting advice to be way off based on proven/verified testing from myself and other members here. I've read some other threads from him in the past and he has some good experience to share. George apparently has a pretty good business going by doing carb work. He wants to make money and there's nothing wrong with that.
I also have experience with carbs. He says he's rebuilt more of them than me and I would assume, running a business, he's right. That doesn't mean he does it any better than me or someone else. At some point, you don't get better, maybe faster? Whatever. The main difference between us is that I try to get others to do their own work. You can see how this is against his interests.
My problem with him is that he misleads potential customers.
>He says he sends you carbs that are vacuum synched on a test bike. He's saying you won't need to vacuum synch them once they're on your bike. The adjustments will stay the same or close enough.
>Since mixture/pilot air/pilot fuel screw adjustments must be made before the vacuum synch, he's obviously saying that those adjustments too, will be good on your bike even though they were also determined on a test bike.
>He also says any jetting or RE-JETTING is installed and then tested on his test bike. This jetting should/will work on your bike, with the emphasis on will.
I find the three above statements to be misleading and ridiculous. You cannot accurately do any of the above unless the carbs are on YOUR bike with your particular set up/engine condition/elevation/climate conditions. You can guess but no more than that. You have to test instead of taking anyones word for fact.
I see why he advertises this way.
His potential customer is mainly inexperienced owners. They don't feel comfortable doing their own carb work, be it cleaning, rebuilding, or jetting.
If the owner realized that the carbs, after he's set them up, may very well STILL need an accurate vacuum synch, accurate tuning screw adjustments, changes to the jetting, possible float level changes, etc.....
that owner may decide "what the heck, if there's a good chance I have to do those things anyway then I might a well try the cleaning and rebuild too". George doesn't want that obviously.
Many owners are on a budget and figure they're saving the price of a vacuum gauge when they try to decide what to do. I'm here to say that they'll need that vacuum gauge or have the bike synched at a good shop if they want the bike to run its best, not just good enough.
George should send you clean and rebuilt carbs. The jetting/adjustments will be guessed at from his experience. When you install them on your bike, your bike may very well run better than it did. It also may be the first time your bike has run at all. It may need minor adjustments, it may need much more than that. You may feel the bike runs great but if you have no experience with a bike like yours, in correct tune, how do you know? Because it doesn't stall? It doesn't spit out the carbs? It warms up fine and idles OK? It doesn't pop? It gets good mileage?
You can have great mileage but what good is it if you're running very lean? You have to test before considering the bike tuned correctly. You cannot take someones word for fact. Not on this subject.
I just want people to make a decision based on truth, not misleading advertizing that tells them what they want to hear.
If that ticks someone off, then so be it.

[Guest]

I hear what you're saying, Keith. One of the reasons I'm so fond of the early air-cooled GS fours (I've had two 750s and now have two 1978 1000s) is that they're relatively simple machines, and even a timid mechanic, which is how I'd characterize myself when I first began working on my own bikes about ten years ago, if he acquires proper tools, works patiently and makes judicious use of the encyclopedic wisdom found here and in the factory manual, can solve just about any problem and do all the scheduled maintenance himself.

All except the carburetors, in my case. I have an exaggerated fear of fiddling with them, maybe because very small changes can create large effects, and usually for the worse. Anyway, the plan is to rebuild one set of 26mm Mikunis this winter and banish the fright forever.

Anyway, enough with the psychotherapy, how about a few photos:

http://s88.photobucket.com/albums/k175/jpmason_2006/GS1000c/

I've been busy at work so haven't had much chance to test ride the new setup. The Vance & Hines header and baffle didn't come close to mating out of the box, so I went to a muffler shop and had them widen the inner circumference of the baffle pipe slightly on this extraordinarily phallic pneumatic device. The junction of the header pipe and the baffle is too loose now, so before I do any fine tuning I've got to shim it with muffler tape and clamp the connection tight.

I did ride it around the block and I gotta say, this bike has got a beastly motor. While my stock 1000 goes from polite to nasty rather abruptly at 6,000 rpm, this thing starts to grunt just off idle, and by about 3,000 you're Evel Knievel looking for a ramp and a fountain to jump.

Wahoo! Just in time for the midlife crisis!

Jack

[pano]

Man, that bike is sweet!

[BadBillyB]

I'm guessing that with the pumped up motor I should select a number or two higher than the stock B8 on the NGK spark plug temperature scale. The bike came with B9's installed and a couple of packs of B10's in the spare parts bin the previous owner gave me. I'd be grateful for any advice from the drag racing drivers on this subject.



Jack

Jack, there is no reason to go to a colder plug with your motor. The B8ES is perfect. Did you ever check and see what cams came in this motor?? Should be markings on the end of the cams. Good reason to check the valve clearance and install the new gasket. Might want to look for some 33 smoothies for that big motor if you ever get the itch for some serious top end power. Now thats a good winter project.......BadBillyB

[KEITH KRAUSE]

I sure am hearing about a lot of header-to-muffler fit problems with the V&H megaphone. My pipe (12005) fit very well (bought 7 years ago/before the "minor" changes to the flanges and apparently overall fit) and this news is effecting my decision to buy a new spare. I did have to find the "sweet spot" by rotating the muffler to a certain position before the pipe would slip together then re-aligning it so the muffler bolt bracket would line up to be tightened. But it seems like others are having fit problems that need modding.
I'm sure that someday soon you won't be able to get a nice new pipe for our bikes and I thought I'd buy a spare for the possibility that mine starts looking bad or whatever. I ride the bike all the time and it's nearly impossible to clean some areas properly, so you will get some rust damage or possibly worse. I plan to keep the bike forever so I would like the insurance of having a new pipe to use.
You would think you could just buy one, check it out cosmetically real quick, and then box it up until the time you need it.
Now it seems that after receiving it, you'll have to take off your old pipe and install (force/modify?) the new one on just to be sure it's going to work. You sure won't be able to return it if you find out it won't fit many years later. Then you'll possibly need new exhaust gaskets when you re-install the old one. All because you can no longer trust a "good" company like V&H?
I don't know if they're just saying "the classic/older bike owners will just have to take what we give 'em or go without", but it's very disheartening.
Why can't they just get the measurements right? Maybe if we all e-mailed them to say they have a problem? Maybe they don't know or think it only happens to a few pipes? Seems to me it's happening all the time.

[KEITH KRAUSE]

Jack, let us know how it runs and if you need help with the jetting.
Get a couple of plug reads at full, 1/3 and minimal throttle positions. Do what the plugs say, they're your window to the motor.
It would be very hard to gauge how well the bike really should be running if you're not used to riding that kind of motor. It may run great but it could have more potential and you wouldn't realize it.
Just a side note about your pic's...I've never seen the oil cooler lines routed that way. Looks like they're rubber and very close to the exhaust? Just an observation.