Bowl levels are the same, sooooo.....

[Scud]

gsBert, one more thing..I have my tank off and gas is not flowing out the supply tube (tank is full), this tells me that the diaphragm is working right?

Scud

 

[gsBert]

not necessarily scud, suck on the vacuum hose, then it should flow in the on position. that tells you the diaphragm is working. dont worry, you shouldnt get any gas out of that tube...

but mostly yeah, unless it's been assembled wrong. as far as i know only yamahas left the factory that way (dual petcocks, one for each carb on their viragos)

did you get that exhaust on yet? my money is with hoomgar at this point...

 

[Hoomgar]

dont worry, you shouldnt get any gas out of that tube...

Unless the diaphragm is bad in which case you could get a mouth full! My petcock would have wet your whistle if you had done that to it last month and it also shut off when not under vacuum. You have been warned! 8O :lol: :lol: :lol: :lol: :lol: :wink:

 

[Scud]

I will forego the 'suck' test, I feel that the petcock is working ok, besides I acquired a taste for 89 octane about two years ago and have been off the stuff since then

My exhaust system will be here tomorrow according to UPS tracking info.

I ordered valve cover, breather, and exhaust gaskets, and the four half moons from my local dealer four days ago, said they would be here tomorrow at the latest....his track record with me has been off by a few days so we will see. :?

As soon as I recieve it all I will be installing...ahhh...this is like christmas only it costs more... :roll:

Scud

 

[KEITH KRAUSE]

I didn't go back to see what you've done recently, but since you have the valve cover off, have you checked the valve clearances? If so, describe how and at what cam lobe position you checked/adjusted them.

 

[Scud]

Keith, yes, I did check valve clearances and all were within spec if not at the tight end of the range but still good according to my manaul.

I checked the clearances as mentioned in the Clymer manual. I turned the crank with the right side cover off and lined up a line with a V mark (inside the right side cover) so that when I looked at the end of the cams there was a notch that was first pointing in (towards the other cam shaft), then I moved the crank (clockwise with the spark plugs removed) to another mark so that the notch in the cam was pointing out (away from each other). It all looked right and looked exactly as describedin the manual.

I just picked up my valve cover gasket and unfortunately the dealer put a 7 instead of a 1 at the end of the item number so IT IS THE WRONG ONE....surprise....I'll have to wait another 3 to 5 days.

Scud

 

[KEITH KRAUSE]

Ok. Sounds good. Kind of hard to stay up to date with these long threads and get it straight what attempts have been made to solve a problem.
I've been through that wrong number crap at the parts counter. :roll: Since I've always dealed with old models and the parts "seem" harder to locate, I always insist on looking at the part number myself for many years now. Most parts guys take no offense. I look at the computer screen and double check the numbers they write down. Works for me.
Let us know what happens.

 

[KEITH KRAUSE]

Another thing, since you're spending the $ :lol:
If your 112.5 main jets are stock, you'll need larger mains for the V&H pipe. I can't say exactly what size to buy, but at least one full size up (117.5) will be needed, maybe up to 122.5 ? Just a suggestion while you're waiting. Others here with your model and similar pipe may help with exact main jet info?
Hopefully, the pipe won't lean out the jet needle circuit too much and require a change. A 1/4 to 1/2 additional turn out on the mixture screws should help with the pilot circuit.
A new exhaust and new gaskets will certainly help the overall performance. Mark was right to bring attention to the exhaust. I should have, simply because it's bad to have a holed exhaust. But I was focused on your one cylinder running lean. Several holes in the bottom of the exhaust as you described would create a more uniform problem across all four cylinders. But how much each cylinder is effected still depends on just where the holes are and how large they are. This is why forums are great. You get more people thinking, as opposed to private messages.
Be sure to measure/compare the new pipe header to the old and how this effects bolt length. Sometimes you need longer bolts for an aftermarket exhaust, sometimes not. Just don't try to make a too short bolt work. If it's getting near final torque and only a few threads are biting, you're sure to see stripping happen. Some people like to apply some anti-sieze to the bolt threads too. Unless your model calls for something else, usually 8-10 ft/lb torque is enough. Also, tighten very uniformly. That goes for the old bolts too...loosen uniformly/gradually to avoid breakage.

 

[gsBert]

oh yeah, DEFINITELY use anti-seize on the bolts!!!

especially if it's the sort of header youhave to remove to do your oil change. unless its a spring-mounted type.

 

[Scud]

I ordered 115 for the main jet, it is a half step I guess, I will try that and see what happens.

I figured that I better check the part number for the valve cover gasket I returned (bad number supposedly) and low and behold when I checked the number at alpha-sport website it defaulted to a new number....the number with the seven on the end....so I figured I was going to get to the bottom of this and took my valve cover to my dealer, he pulled out the returned gasket and it fit perfectly...huh??....had some explaining to do but to no avail, it fit like a glove...how could that be?, I looked at that sucker for ten minutes and no matter how I turned or flipped it it would not line up. He had some smart aleck, painful remark and I left with a bruised ego, but managed to get over it.

So....I put the gasket on, attached the cover and put my carbs back in (felt Like I went eight rounds with a middle weight boxer getting them back in...it was all to familiar after ten minutes..). SO now all I am waiting for is my exhaust gaskets and if they do not arrive today then tomorrow they should be here and I can get it all back together.

I plan on synching first before takin her out for a ride to check plugs etc.

Thanks fellas,

More to follow.

Scud

 

[Anonymous]

Holy crap, I just spent 45 minutes reading this start to finish. The suspense is killing me; did the exhaust fix the problem?

I hate to make this thread any longer, but I have a few suggestions for checking some things that were mentioned along the way.

First, on the compression check. Quick way to check if you have a burnt valve or bad rings: Bring the cyl you want to check to TDC on the compression stroke. Using an air nozzle with a rubber tip, pressurize the cylinder with about 50-psi. listen at the exhaust and then the airbox. if you hear air out of either one that corresponding valve is leaking. Next listen at the case vent, if you hear air escaping, rings are the problem.

Second, Vacuum leak check: with the bike idling, spray carb cleaner on the intake connections, vacuum lines, intake pipes, etc (avoid spraying the exhaust pipes). If the idle climbs, that is where you will find your leak.

Third, it was mentioned that the carbs were dipped and the air screws were not removed. This may not be a problem on this model, but if there are rubber O-rings sealing those needles, they would surly have been damaged if not completely dissolved.

Just my two cents, er' three cents... Maybe help somebody down the line.

 

[Scud]

well.....we will have to wait and see....in about tem minutes I am off for Idaho Falls for an early morning departure.

I spent most of the afternoon installing the new exhaust and synching the carbs, it ran great and idled very smoothe 8)

I will check the plugs when I return from my business trip on the 18th.

Stay tuned...the suspense is also killing me!!

Scud

 

[gsBert]

the suspense is killing you????

can you guess what its doing to me???

get back to us soon with the verdict.
and enjoy the ride

 

[Scud]

wWll do, I will get back to my bike on the 19th.

Scud

 

[Hoomgar]

Your going to have it beat Scud

 

[Scud]

Ha!...I am back and had a chance to take her for a short ride today. Well.....she started right up but when I went to accelerate there was this bog and I could not get up to speed unless I went easy on the throttle....hmm...It acted like there was either not enough gas or too much air......the sheet that accompanied the Vance and Hines 4-1 exhaust said to' remove the airbox lid' for my particular bike (1980 GS 750E), so I did, but after my short ride I thought...what the heck...I am going to put it back on and viola...she ran perfect....pulled hard through all the gears and sounded awesome .


Could it be becasue I live and ride at 6,200 and higher that I need to keep the lid on my airbox?......anyway...I pulled the plugs after another, longer ride and number one is still white, number two is dark tan, number three has lightened up considerably, almost like number one but not quite and four is like three.

I went from a 112.5 main to a 115.0, should I go to what the literature says and get 130.0 mains...seems like a large jump to me, especially after she runs excetionally better when I put the airbox lid back on...not sure I want to trust what they say :? .

Hmmmm......

Scud

 

[gsBert]

well, the lid off the box might flow more air, so yeah, you should go for the larger mains in that case... as far as altitude, that's almost 2 kilometers above sea level, less oxygen therefore you should be jetted a bit more lean than at sea level for optimum performance. the lid off would lean it out, but if they recomment 130s the lid on might just richen it out enough since you still have the stock jets.

seems like you were running lean until the slides rise enough.
could also be the turbulence in the airbox because of the removed lid, but my bet is lean

i'd say keep the lid on and use 120 or 117.5 if you can find them. actually i would put 120s on 2 and 3 and 117.5 on the 2 outsde cylinders as they get better air cooling.

hmmm number one is still white?

im curious, did you see a performance improvement from the pipe? and it's in the ports nice and tight and flush right?

i push my pipes in with a spreader bar so they're in tight then screw them on, then i check for leaks with cigarette smoke before putting the muffler on (yeah, its loud, but the weight of the muffler might make the pipes not get in straight)

back to the white plug. you did put in 4 new plugs right? if not, do that before any other testing and do plug chops at 1/8 throttle, 1/2 throttle and at full throttle to determine if your jetting is right on the pilot, needle and main respectively. warm the engine up with your old plugs first so you dont gunk them up from being on the choke.

if you wanted to go overboard:
you might want to get an air/fuel meter and weld some mounting nuts on your old pipes to screw in the o2sensor. (i'm gonna do that on my bike)
put a nut on each headpipe and plug them with bolts (not too long) you plug the o2 sensor in each pipe about 1.5 feet from the port and determine the mixture SCIENTIFICALLY while riding at different throttle openings. then you jet accordingly. it's actually pretty cheap if you get a new non heated o2 sensor and just plug it into a recording/graphing voltmeter if you have one... i can get you the voltages for rich, lean and ok if you want, i still have them somewhere from my racecar days...
else, an air/fuel meter is pretty cheap (around 30-50$) and if you can do the drilling/welding youre set.

it's weird that #1 is still white. if they were new plugs, they should all look alike. i know you did a compression test and that was good. did you do a leakdown test? cyl #1 might have a non completely closing exhaust valve, if you pressurise the cyl at tdc you should not hear air escaping out the tailpipe (dont put 250 lbs of pressure into it! 40 or so should be enuff)

this is an interesting problem you have, it keeps me busy and thinking, distracts me from my bike which is good. bring me the bike, lol, we'll work it out.

seriously, we've ruled out the exhaust IF its bolted on right AND you used NEW plugs. it wasnt a waste of cash as your new pipe rocks! and we've eliminated that. (exhausts can be a problem, my jetting problems on the 1150 have been solved by using a new pipe, the old one was f@#!ked up and the bike no longer smokes after putting on the 4:1 from my 750) so that is a good step forward. as well as an easy one.

i'm curious about one other thing now, (im assuming its carbs or an intake leak or a exhaust valve), a good way of eliminating the carbs is jet #1 richer and leave the rest alone (stick a 120 in carb 1), does the plug stay white?
if yes, jump on the leakdown test, if that works out, you have an intake air leak. (if the exhaust for #1 is in tight of course, and since your pipe bends right, #1 is easy to undertighten, check with cigarette smoke or a candle flame)

i know this is long and i just gave you a lot of things to try, but it HAS to be one of those 3, so start wrenching again, and let us know.

 

[KEITH KRAUSE]

Without reading back, you did say the carbs are positively clean and the floats levels are set? If so, then I'd adjust the mixture screws for highest rpm and then re-check/synch the carbs.
As for your main jet, 115, a 1/2 size up, isn't enough as I said earlier. I'd guess 120 or close to. This is with the air box lid still on.
I don't know why V&H goes around telling customers to remove the air box lid just because you install their pipe. Sure, removing the lid will increase power IF you re-jet correctly, but they shouldn't assume anything. Removing the lid will insure the need to raise the jet needles. It's a much leaner condition than just the pipe. You can still have trouble re-jetting, but removing the lid will probably increase the difficulty.
As for what jetting your bike will need, you have to test by throttle position, note performance/take reads. Mark your throttle housing and grip and test for the needles at 1/3 throttle for a couple miles. Chop off and read. Full throttle for the mains. About 35 mph steady in 4th gear on level ground (minimal throttle position) will give you a decent pilot circuit read. Also pay attention to how the bike warms up, how it idles, how it re-starts when hot, any decel' popping, etc. Do what the performance/plugs say.
Be SURE the carbs are vacuum synched before taking reads. Before synching, the valve clearances must be correct and the ignition timing correct and the mixture screw adjustments.

 

[Scud]

gsbert - I did see an improvement with the pipe, more power for sure, and yes, I put in new gaskets and torqued accordingly, at least they all seemed to seat nicely in their respective ports.

I did not put in four new plugs but will after I get my new 120 mains, I will then vacuum synch and do the plug chop. Good idea about warming up with old plugs, I will do that to.

My old pipes I took to the dump, they were shot....

I did not do a leak down test, while I had the valve cover off I checked all valves and they were all within spec and almost identical to one another.

I like the idea of jetting number one richer and leaving the others alone, after all, I am getting faster at taking the carbs off and putting them back on! (love that stock airbox..)


Keith - Yes, carbs are spot clean and levels are on (I checked them again while they were off last time). I will indeed order the 120's after this post from Dennis Kirk.

I know, why would V and H want you to ride around without your airbox lid on, I mean it gets dusty around here at times in a town of 800.

Once I get the new jets and plugs I will do as you mentioned with regards to the throttle chop and read plugs.

As I told gsbert, I checked the valves when I had the cover off and they were all within spec and almost all identical. I have a morgan carbtune that I have used seeveral times already and feel confident in my ability to synch with it.

Thanks guys, I will start on the project again when the jets arrive and will let you know what I find. And again, thanks for all the information.

Oh yea, and thanks Earl for the PM

Scud

 

[KEITH KRAUSE]

If the PM from Earl involves trying to get the bike running well, shouldn't we be working together and sharing info. We all learn from this.