80 GS750 lives- now the hard part

[Texatl]

Still messing with the idea of a jet kit, BUT... something about the way its running has been nagging at me.

I messed with it for a while today- very very frustrating. Went anywhere from 1 to 7 turns out- and not ONE freakin difference.

I've checked the boots- good. How can this be that hard? I know I have a hard head, but please help me understand- HOW can taking the airbox off make the bike NOT respond to throttle. I have done this all kinds of engines, and they at least run and respond. Example- take the air cleaner off anything- it should still run and respond to throttle. So how are the pods any different?

I'm not saying it should be perfect and not effect it at all- BUT why won't it respond at ALL???!?!?!?

It idles really high- 4K and sometimes when I let off the throttle the RPM's spike as tho it just got its gas finally.

Ugh- I freakin quit. If this bike didn't have a title, I'd burn it to the ground and not stop until it was a pile of molten metal and rubber. But since it has a title, I feel that part can be useful for something.

I quit.

[TheCafeKid]

Still messing with the idea of a jet kit, BUT... something about the way its running has been nagging at me.

I messed with it for a while today- very very frustrating. Went anywhere from 1 to 7 turns out- and not ONE freakin difference.

I've checked the boots- good. How can this be that hard? I know I have a hard head, but please help me understand- HOW can taking the airbox off make the bike NOT respond to throttle. I have done this all kinds of engines, and they at least run and respond. Example- take the air cleaner off anything- it should still run and respond to throttle. So how are the pods any different?

I'm not saying it should be perfect and not effect it at all- BUT why won't it respond at ALL???!?!?!?

It idles really high- 4K and sometimes when I let off the throttle the RPM's spike as tho it just got its gas finally.

Ugh- I freakin quit. If this bike didn't have a title, I'd burn it to the ground and not stop until it was a pile of molten metal and rubber. But since it has a title, I feel that part can be useful for something.

I quit.

Dude. It doesnt respond to throttle because the fuel air mix is totally screwed up. If you havent put jets in it, your are NEVER EVER EVER going to get that bike to run right. Period. That bike is so lean right now, the only thing letting it run period is likely the choke circuit. You have to rejet. Its not an optional thing. Of course the screws arent going to make a difference because there is no difference for it to make. The amount of fuel coming in by having those screws out is so minimal that its not going to be an audible change.

[dtkid]

As I think was emphasized previously, these machines won't run without the proper mixture. When we stated that, previously, I didn't mean they wouldn't run good; I meant that they would not run.

[Texatl]

I read what you are saying- but it does not make any sense. Taking the air cleaner off an engine renders it useless???? In my small brain that does not compute.

All I'm saying- it should still respond to something. Not perfectly- but something.

I'm not trying to be difficult, but I really want to understand. It doesn't help that I'm getting impatient, this has been the longest period off a bike in the last 5 years. PMS at its worst.

[TheCafeKid]

Everything in the carbs and combustion chamber relys on a controlled amount of air vs a controlled amount of fuel. By removing the air box, you have taken off the restriction that helped controll the amount of air the carbs and motor are able to take in. This introduction of this uncontrolled air screws up the delicate air/fuel ratio, making the mixture inducted into the combustion chamber incredibly lean. So, it may run at idle, (and I say MAY) but here's what happens next. You feed some throttle. The butterflies in the carbs open when you turn the throttle. The motor now sucks EVEN MORE air. But you've not increased the jet sizes, so the poor carburetors cannot pass the extra fuel needed keep the air/fuel mix at even a burnable mixture, let alone an optimal mix. So the bike croaks. Its that simple.

[Texatl]

OK- so I did explain before I am a carb neophtye and I am trying to wrap my brain around all of this.

I guess I'll see how it goes when the parts come in. Until, and because I am tinkerer- I am going to run a wee bit of a test. Just fiddling. But could be interesting red neck engineering at its best.

FYI- I found the jet kit on eBay for 99+shipping (like $6 I think). MAW has it for $106 +shipping. No longer in stock on Amazon.

[Texatl]

Redneck engineering paid off- and the test concluded that you are all correct and "Masters of the GS Universe". I am man enough to admit I was wrong.

Its now responding to throttle revving and lo and behold I actually rode the darn thing (only on my property, but its a start).

So- like I said it was some redneck work to restrict airflow. So when The airbox is prolly the best idea (for now), Jet kit for later.

So couple of tech issues left-

1) Why won't it start with the starter button

2) why does it idle so high- its idling at like 4K rpm.

[Texatl]

Air box arrived and mostly installed. For the love of all thing Holy- HOW do you get the airbox boots over the two center carbs?!?!?!?!?!?

I had a nice fight with the bike to get it back where it needed to be, but the center boots are still not on all the way.

Once I get the boots on (hopefully with some GSR help :-) ) I can try to start and tune her. Hopefully this helps.

[Texatl]

Bump- I really need some pointers on getting the airbox on completely. I'd like to try starting her up tonight.

Thanks in advance!

[basic]

it's a PITA to get the airbox/carb boots on completely, especially if they are old boots. you can try silicone spray on the boots to get them to slide on more easily, but other than that it's a LOT of time and some choice words and they will go on, hopefully. I got so tired with dealing with mine that i got some new carb/airbox boots and used real hose clamps and that seemed to work.

as for the starter button, mine did the same thing, turned out to be the clutch safety switch. I bypassed the switch in the headlight bucket and it seems to workjust fine.

[Texatl]

Ohhhhh- well then... I've been in and out of the bucket recently doing turn signal crap, maybe I jiggled something or disconnected on accident. Thanks for the heads up.

Oh yeah- Silicone spray will be bought this afternoon. Thanks!

[Texatl]

Well- Looks like I need new rubbers for the sirbox and while I'm at it I'll get new for the carbs/intake as well.

Also- anyone have a filter box???? This is last part needed to rturn to stock.

I did run the bike this weekend with the airbox on, and a makeshift filter over the hole. Ran better and quieter ;-). But boy there was a lot of white smoke out the tailpipes and it finally idled around 1000rpm. Also, getting a lot of fuel back on the air box . I'm going to chock this up to not having everything right just yet as it seems I'm now opposite from the other issue.

The white smoke smelled very much like raw gas and the smoke dissipated after a bit. So maybe I'm a rich now, instead of the lean position I was in before.

Anyway- once I find a filter box I can start tuning. But, def. getting some rubbers in the meantime as well.

[Texatl]

OK- so I broke down and ordered the DJ Jet Kit. And viola- it purrs like a kitten now.

Thanks for everyones patience and advice. Maybe, just maybe, I should have listened a long time ago.

Now its off to track down why the oil light stays on, and adjust the clutch (again...)

Thanks again!