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Hi, I just got a 1988 Gixxer 750. It's not running and missing a few parts but I have vision! I got it with the gas tank removed and need to know what hoses go where. It's obvious the two hoses from the carb bowls go to the petcock. But there's a hose coming from the plastic diaphragm cover, where does that go? And, there is a rectangle shaped plate (same color as the head) bolted to the top middle of the head with a hose type nipple on it that seems to push out air when cranking over. Is there supposed to be a hose on that and where is that hose supposed to go.

I'll assume the nipple on the bottom of the tank in the middle is supposed to have a hose for drainage since that leads right up to the gas cap. But there's another nipple on the bottom near the back of the tank. What goes there?

Finally, probably a stupid question. Do the air filters need to be installed for it to run or can I keep them off while trying to get it to run for the first time?

If anyone knows the hose routing or could look at their bike for me I would GREATLY appreciate it.

Thank you
-Peter
 

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Originally posted by prabbit:
Hi, I just got a 1988 Gixxer 750. It's not running and missing a few parts but I have vision! I got it with the gas tank removed and need to know what hoses go where. It's obvious the two hoses from the carb bowls go to the petcock. But there's a hose coming from the plastic diaphragm cover, where does that go? And, there is a rectangle shaped plate (same color as the head) bolted to the top middle of the head with a hose type nipple on it that seems to push out air when cranking over. Is there supposed to be a hose on that and where is that hose supposed to go.

I'll assume the nipple on the bottom of the tank in the middle is supposed to have a hose for drainage since that leads right up to the gas cap. But there's another nipple on the bottom near the back of the tank. What goes there?

Finally, probably a stupid question. Do the air filters need to be installed for it to run or can I keep them off while trying to get it to run for the first time?

If anyone knows the hose routing or could look at their bike for me I would GREATLY appreciate it.

Thank you
-Peter
<font size="2" face="Verdana, Arial">Ok, the bike will start with the choke with no air filters, but unless it's been jetted to run without the filters, it won't accept throttle at all (it will be way too lean).

On the hose routing...

The nipple on the top of the valve-cover that you describe as:

"rectangle shaped plate (same color as the head)"

is the crankcase vent. It can be left open, but you really should have a filter on it (I have a 2' length of hose and a small round cotton-gauze filter on mine) to prevent dust/dirt from entering the crankcase when there's negative pressure there. It will also tend to vent oil vapor from that nipple, so if you do route a hose and filter from it, put the outlet somewhere that you don't mind getting oily (not pointed at the tires).

The petcock has two 5/16" nipples that feed the carbs and also a single 3/16" or 1/8" (I haven't measured it) nipple that must be connected to the vacuum nipple on one of the carbs (#3 is the one the factory used).

The fuel feed for the carbs is of course the two nipples between 1&2 and 3&4 on the bottom. The two nipples between 1&2 and 3&4 in the top half of the carb-bodies are just vents. They were originally connected to the airbox with tubing, but you can safely leave those disconnected (mine are disconnected because of the individual filters I am using).

On mine, the nipple on the left-rear of the tank is the one that drains spillage and water from the filler-cap... there is also a fuel-level sensor in the tank that has a cover and drain (that doesn't connect anywhere, just routes fuel away from the hot engine in the event of a leak) I think that's what you described as a "plastic diaphragm cover" ...that one isn't really part of the tank though; it's a seperate part.

I don't have any other fittings on the bottom of my tank. I am sure that the CA model tank has some sort of provision for a charcoal cannister, and that may explain the extra nipple you have there. CA-model tanks have a larger-than-usual fitting on the top-vent for the tank too. You can easily see what I mean if you look at the pic below...



The parts with the red-arrows are what I mean... #'s 11 and 12 are the CA-spec parts, 8 and 9 are like my bike. I dunno how the heck the hoses are routed for the cannister if you have a CA model... I can't seem to find a good drawing or pic of it anywhere either. I *think* you can get away with simply blocking off the fittings and ditching the cannister... but don't tell the EPA. One of the gurus here might know more about that.

I hope that was helpful... it only took three tries to get the damn drawing to display so ya could see it LOL

[ 09-27-2002, 08:49 AM: Message edited by: FastCat ]
 

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FastCat's steering you the right way. The extra hose on the petcock is for vac and needs to be hooked up in order for fuel to flow. the crankcase vent needs to be filtered to something (I have a little K/N on mine so that I can clean it) if your going to run the stock airbox there is a fitting on it for this. The drain from the cap needs to be routed away from the engine and tires (it also vents water that gets down between the outer ring and the tank) the factory routes a hose to down near the sidestand. The other nipple at the back of the tank on mine just has a cap on it. When I find my manuals (I just moved) I will look up the hose routing but as you are in CA it is probably smog stuff. As you have a 750 you do not have a fuel level sensor like FastCat's 1100.
Bones
 

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Originally posted by Bones_GSXR:
The extra hose on the petcock is for vac and needs to be hooked up in order for fuel to flow.
<font size="2" face="Verdana, Arial">Maybe not. Try turning the fuel petcock in the direction opposite the "reserve" setting, and I bet fuel runs out freely even when the engine's not running.
That's the "prime" setting for engines that have dry carb fuel bowls, like when they've been sitting too long.
 

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Discussion Starter #7
Thank you everyone! Your info helped A LOT! I got the hose routing down, the tank derusted and coated with kreem and I GOT IT STARTED! I had a few fuel leaks (dry seals). I ordered some new bowl seals and fuel inlet nipples with seals so I should be ready to take a ride in a couple weeks.

Spike52, thanks for the offer! A friend of a friend (you know how that goes) says he had a manual for his bike like mine a few years ago so he's going to try to find it. I'll give him a couple weeks and let you know but THANK YOU SO MUCH FOR THE OFFER Spike!

Thanks again to all
-Peter
 
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