85 GS450 issues ( 3 seperate ones)

[southern menace]

1- This is my first post on this site. I have tried searching the forums for some info but am not having much luck. I put some K&Ns on the bike and of course it runs like ****. I am also running straight exhausts, no baffles whatsoever. I took the carbs apart, and reamed out the main jets, and also raised the needle by reversing the large and smaller plastic washers that were already in there, since the needle has no grooves in it. This did make a world of difference, but it is far from perfect. The bike wont idle right, it spits and pops. Once I get the RPMs way up it has a ton of balls and sounds great, but it is no good in the low range. I have looked for a dyno kit, and it seems that they are not available for this bike. I dont know what size jets to buy, or where to buy them. What can I do? And finally how do I sync these carbs?

2- The second issue is that one of my CV diaphrams has a tiny pinhole in it. I have repaired it with some kind of rubberized sealant. Is this acceptable, or am I going to have to bite the bullet and spend $90 on a new one?

3- The third issue is the one that causes me the most concern. I recently pulled the engine and painted the entire thing with heat paint. Now i can see what looks to be either fuel or oil is starting to stain the fin on the head right near the head gasket. Is this typical, or am I going to need to pull the head off and replace the gasket? Could it be sucking air causing the problems with the way that it runs?

 

[Steve]

1). OK, I can understand the K&Ns, but why straight pipes with no baffles? Unless you live out in the boonies where absolutely NOBODY else will hear you, you are not doing much to promote the image that motorcyclists are reasonable, responsible people. Sorry, but that's the way I feel. I would also venture that if you were to put your bike on a dyno, your power increase will likely be considerably less than 10%. Is all that noise really worth it?

You "reamed out the main jets." With what? What size are they now? Even if you used a proper-sized jet drill, there is too much variability to guarantee a straight, accurate hole. Your best bet will be to buy new jets and leave them alone. If you find you don't have the right size, buy another size. The differences from one size to another are too small to see.

What size jets do you need? What size did you start with? Determine the stock size and go up from there. With K&Ns and open pipes, figure on adding about 20 to the main jet size.

2) Bite the bullet. Whatever sealer you used will be affected by constant exposure to gas vapors in the carbs and will soon open up the hole.

3) It is not unusual for there to be a small leak at a gasket. Based on what you said in number 1, I would think that this issue would be the one to cause you the least concern, not the most.

Chances are that all your spitting and popping are fuel-related. The pinhole in the diaphragm and the "reamed out" main jets are not helping one bit.


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[earlfor]

Usually, open pipes produce less power than a stock system. They also decrease fuel milage and increase noise.

Earl

1)I would also venture that if you were to put your bike on a dyno, your power increase will likely be considerably less than 10%. Is all that noise really worth it?

 

[southern menace]

My reasoning for the straight pipes is two fold... 1- There were no mufflers on the bike when I got it, and even if they were there, I would have chopped those silly megaphone pipes off anyway. 2- The county that I live in has the most car accidents in the entire state. People dont know how to drive, and the ones who do arent looking for motorcycles. I am not going to sneak up on anyone and have them merge into my lane. Whether you believe it or not " loud pipes save lives ". I will be heard long before I am seen. Im not really concerned with the loss, or gain of power. I didnt put the K&Ns on to gain power, I put them on to get rid of the ridiculously huge airbox so I could remove the cheap plastic side covers. Thanks for the advice on the carbs bud.

 

[doggscube]

Whether you believe it or not " loud pipes save lives ". I will be heard long before I am seen.

While I don't completely discount that saying, loud pipes don't help you with the most dangerous situation of someone failing to yield to you as you approach them, unless you turn one of those straight pipes around to point forward. :-D

Jeff

 

[Steve]

Whether you believe it or not " loud pipes save lives ". I will be heard long before I am seen.

I am more inclined to go along with the AMA on this one..."Loud pipes lose rights."
Many places are closed to ALL motorcycles because they don't want the noise that is (unfortunately) usually associated with them.

One disadvantage of being heard before you can be seen that you may not have considered...
they heard you, they didn't see you, they stopped looking, they hit you anyway.
Some might even aim for you, because of the loud pipes.

I have been riding in a downtown area with tall buildings (10-20 floors) and heard loud v-twin engines echoing. While riding through an intersection, I found the loud bike. It was a block away, riding parallel to me. That will definitely not save any lives.

I also had a friend that had loud pipes on his Harley. He shared your philosophy about "loud pipes save lives." His full-time job was as a paramedic. I asked him if, while driving, he ever had anybody pull out in front of the ambulance. He said, "yeah, it happens all the time." OK, if they can't hear the sirens and see all the flashing lights, one bike with a tiny headlight and straight pipes pointing backward sure isn't going to make a difference.

Is that your bike in the picture? Nice work of art. I don't think I have ever seen front suspension like that. Based on the seating position, the seat itself and the lack of rear suspension, I don't think you will be venturing into my hearing range any time soon, so please enjoy your ride.


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[mortation]

OUCH! Everyone is really nice here. Loud pipes are just a touchy subject right now. I like loud pipes too. Within reason of course

Loud pipes and internet arguments aside the answer to some of your questions

1) I dunno I'm in the same boat myself! Minus the strait pipes

2) Buy new diaphragms. Check on eBay or post in the wanted section here. Someone will help you out

3) It is probably leaking. Try spraying it with a little carb cleaner, and see if your RPMS pickup. You could try water/WD40 and see if they drop. Considering how much you already tore the bike down I would say pull the head

 

[Nessism]

Yup, lots of anti noise grumps around here...including me!

Someone took a perfectly nice bike and made it so it won't turn or stop, and will punish the rider with no suspension. I suppose that's a personal choice. But inflicting noise from open pipes on other people is downright rude and crosses the line. You can be free do do what you want but you do not have the right to force your version of freedom on others.

 

[southern menace]

Alright, alright!

Alright, alright!

The purpose of my thread wasnt to start an arguement about noise. Obviously we all have our opinions, and that is how it should be. We all have the right to use our bikes to make statements about ourselves and our lifestyles, and nobody here has the right to persecute anyone else for doing so. That being said, I would still like to hear some more opinions about my problems, except the diaphram, that one seems to be pretty staight forward.

 

[Steve]

... I would still like to hear some more opinions about my problems, except the diaphram, that one seems to be pretty staight forward.

Sorry if the rant on loud pipes got you distracted, but I think I gave you decent advise about #1. Your "reamed out" main jets are of a totally unknown size and will give you fits until you replace them with something that has a known value. According to the carb sticky for your model, it came with either 115 or 120 main jets. Considering the K&Ns and straight pipes, you might want to try 135 or 140 mains. Install the new mains and new spark plugs, do some plug chopps to read the color of the plugs, then tune accordingly.

#3 is also answered with straight-forward facts. Small leaks are common. Don't worry about them.

According to Haynes

US 450 models:
Make: Mikuni
Type: BS34SS
Venturi Size: 34mm (1.34 in)
ID number:
ED: 44400
LD, TXD, LF: 44460
Other models: 44110
Idle Speed:
ED, LD, TXD: 1200 +- 50 RPM
Other Models: 1200 +- 100 RPM
Fuel Level:
ED, LD, TXD, LF: 5.0+- 0.5 mm ( 0.20 +- 0.02 in)
Other Models: 6.5 +- 0.5 mm (0.26 +- 0.02 in)
Float Height:
ED, LD, TXD, LF: 23.0 +- 1.0 mm (0.89 +- 0.04 in)
Other Models: 22.4 +- 1.0 mm (0.88 +- 0.04 in)
Main Jet:
ED: 120
Other Models: 115
Main Air Jet:
ED, LD, TXD, LF: 0.7
Other Models: 0.6
Jet Needle:
ED: 5DX87
LD, TXD, LF: 5CDT60
Other Models: 4C2
Needle Jet:
ED, LD TXD, LF: 0-6 (O-6??)
Other Models: Y-6
Throttle Valve:
LF: 95
Other Models: N/A
Pilot Jet:
ED, LD, TXD, LF: 45
Other Models: 17.5
Bypass:
ED, LD, TXD, LF: 1.0, 0.8, 0.9
Other Models: 0.8
Pilot Outlet:
ED, LD, TXD, LF: 0.7
Other Models: 1.1
Float Valve Seat: 2.0
Starter Jet:
ED, LD, TXD, LF: 32.5
Other Models: 30.0
Pilot Screw Setting:
ED, LD, TXD: Preset (2.0 turns out)
Other models: Preset
Pilot Air Jet:
ED: 135
LD, TXD: 145
LF: N/A
Other Models: 1.6

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[southern menace]

Thanks for the advise guys. The only reason I reamed the jets was to get some more fuel in there, to see if I was on the right track. I am pretty carb. dumb! It did certainly help, but Im sure trying some real jets will probably do the trick. Ill be ordering them tonight. What do you mean when you say " tune accordingly". It seems that the only thing that I can do is put in new jets, since the carbs dont even have an air mix screw. It says in the manual that they are preset, and no adjustments are needed. Obviously they dont plan on you modifying the intake. What can be done? Should I try a smaller pilot air jet? Also what is the general opinion about raising the needle valve? I seem to have found some conflicting info on this site. If I do raise it, how far does it need to go in relationship to the increase in main jet size?