gutless/gashog 450ga

[tkent02]

Oh, didn't notice that.

[bob_coakes]

Agree with checking the jet sizes. The bike should get at least 40 mpg. You also might want to measure fuel level in the float bowls, not just measure float height. The carbs may be overflowing and sending fuel into the cylinder inadvertently. And speaking of that, what color are the plugs. The plugs are likely pitch black from burning so much extra fuel.

Right now I'm running a set of champion plugs that are supposed to be a little hotter than the NGK ones that were in it when I got it. The plugs look like new and I've put probably 300 miles on them. I've wanted to do a chop test at full throttle to see if thats where I'm wasting all that excess gas but there is no way to clutch it since its an automatic, if I kill the engine its still turns before I can get it in neutral.

[bob_coakes]

An 1100 should get 40mpg cruising, a 550 more like 50. Don't know, never ridden a GS 450 much but shouldn't it be more like 60mpg?

A few more things to check, any one of these can only cost a little bit of wasted fuel, but combined they can cost a lot more... It seems to multiply.

These are just the things that I have seen, there are more.

Drive chain and sprockets worn, or of the wrong ratio. Too low RPM at cruise and the mileage will suck, these engines need to spin at high RPM to be efficient. Same with your riding style, lugging it around like an old lady is very inefficient. Brakes dragging. Choke not closing completely on one or more cylinder, is the little lever on one or more plungers upside down? Choke cable too tight? Fuel dripping out the overflow as you ride. Tires too wide, low tire pressure. Spokes loose. Rider too fat. Vacuum leaks. Missadjusted intake or exhaust valves. Ignition timing off a little bit. Cam timing off one tooth. Restriced or even blocked exhaust. Air filter too restrictive, or not sealed right. Airbox not sealed. Clutch slipping. Wheel bearing shot, allowing the wheel to wobble. Wrong oil weight. Worn or incorrect spark plugs. Improper ignition points gap. Bad spark plug wires. Wheels misaligned.

Good luck finding what is going on.

The bike is almost completely stock. I bought it as a pair of parts bikes so I've picked the best parts of each to make one complete. Its a shaft drive and has clean final drive oil that I changed when I first started putting it together. It has the stock airbox with newer boots (no cracks and new o-rings) and the air filter is brand new. Valves have been checked and are within the range. Ignition are new NGK coils. I don't know how old they are but they look new and have lots of spark from personal experience (I grabbed one once because I didn't think it was firing but it was). Oil and filter are new and same weight as what is cast on the housing to use. Breaks are probably in need of replacing because they are a little thin but not sticking. Carbs have been dipped, I didn't mess with the choke but the gap was closed on both.
I'm still new to riding so I don't hammer on the throttle or anything like that. I ride fairly reserved. I can't think of any mechanical problem it could be but I'm to the point where I'll try just about anything as long as its not too expensive. I'm already in it as much as its worth.

[Steve]

i have an 82 gs1100gl, i have the same issue, wet plugs, wont rev past 5-6k, only 70mi to a tank. desperate for help

Welcome to GSR, but please don't clutter up another person's thread, start one of your own.
As you might have noticed, everyone has pretty much passed over it, because it's buried in someone else's thread.

Right now I'm running a set of champion plugs that are supposed to be a little hotter than the NGK ones that were in it when I got it. The plugs look like new and I've put probably 300 miles on them.

That could be part of your problem. Use the proper NGK plugs, probably B8ES. I have always questioned the wisdom behind that, thinking that "a spark plug is a spark plug" (all other things being equal), but have since found that, for some reason, these bikes seem to know when anything besides NGK plugs are installed.

Also, having them in a hotter range is not helping you any. It is possible that you are running WAY too rich, but the hotter plugs are masking that, letting you think that everything is just hunky-dory.

I've wanted to do a chop test at full throttle to see if thats where I'm wasting all that excess gas but there is no way to clutch it since its an automatic, if I kill the engine its still turns before I can get it in neutral.

The most important part is that you kill the engine, THEN release the throttle and coast to a safe area where you can check your plugs.

.

[jeffasaurus2]

I've got the 450T, even when I'm racing around town I'm averaging ~50mpg. On the highway, more like ~65mpg.

You asked earlier about proper vacuum gauges, I sync my carbs every time using this set-up, it works quite well with the twin cylinder bikes.

[bob_coakes]

I got a new set of NGK plugs so I'll try them and sync the carbs again. About how many turns out should I have my pilot screws turned out? I had them set at 2.5 turns open after I dipped them and then adjusted to 1.5 turns but it doesn't seem to make much difference in how it runs.

[terrylee]

Might make sure the tips of screw have not broken off inside carb. You should notice a difference between those number of turns. terrylee

[bob_coakes]

So last weekend I finally had some time to do some work on it and take it for a ride. I did a correct chop test with the old plugs still in and at high throttle, the plugs came out black. I change the plugs and put the pilot jet screws from my parts carb into the carb thats on the bike. The screws I took out looked fine, not broken, threads were fine, but they did look like they were bent a little to the side. After I put it back together and did another chop test, the new plugs came out clean. I put on over 200 miles this weekend and averaged 38 mpg riding in the city and open highways. Not sure what the problem really was but its much better than the 10-20 mpg I was getting before. Thanks everyone for all your help.