suzuki GS450E wont go 50 mph or better

[C0TT0N]

hi all,

Suzuki gs450e. It sat for 5 years then i bought it 4 days ago. when i first started riding it the bike would spit and sputter and backfire. after the past 4 days of riding it with high test gast and a carb cleaner everytime i fill up it doesn't do any of that anymore. the problem now is that the bike will not go over 50 mph and has a hell of a time getting up hills. the bike starts fine and idles fine. hardly any "get up and go" to it. There are NO modifications to the bike. that i can tell. The bike just eats up the gas. im only getting about 50 miles to the tank...if that. No manual came with the bike but i assume its about a 2 gallon tank. after riding there will be a small puddle of gas on the ground that appears to be coming from an overflow hose. this is only after riding or having the bike idling for over 10 minutes or so. I tried to regulate the amount of gas going in by playing with the primary to reserve valve but none of the settings seem to be helping. please help. trying to get it ready to go riding with buds on july 4th. anything will help but i am trying to prolong the inevitability in which others seem to think that the carbs need rebuilt. ugh. thanx

[Clint]

Welcome. You probably have quite a bit of fuel varnish that hasn't been cleaned up by the in-tank cleaner. You'll need to pull the carb(s) apart and clean them properly. Sounds like the main jets are clogged, and the float valves are leaking, allowing the fuel to drip out.

Do you have any mechanical experience? If not, you'll need some basics on carb theory and diagrams. It's not hard, but you could do some damage if you're not careful. You'll also want to keep track of the current settings of the air/fuel screws by turning them all the way in while counting turns.

Let us know what you need help with.

[C0TT0N]

I dont have any mechanical experience. where can i get the diagrams. also is it "recommended"? or "required"? to get a build kit for the carbs. also the few people that looked at the bike and tried to offer advice said that the carbs for this bike did not have an outside adjuster. is this a concern?

thanx for the help

[Clint]

As with anything, it depends. If the diaphragms are torn or the jets worn, you'd be wise to replace them. I'll see if I can find out what carbs it has so I can help more. In the meantime, please fill out your profile. We at least need to know what year it is.

[C0TT0N]

ok. great. thanx alot

[C0TT0N]

its a 1983 suzuki gs450e

[Clint]

I'd start here. Carb work shouldn't be too challenging if you can follow directions.

GS450ED Repair Manual Search Page Suzuki 1983

[C0TT0N]

sweet...thx rowdy..ill let ya know how it goes

[Aussie Steve]

You might like to check the air filter while your at it.... all that carb cleaner and spitting and sputtering tends to dirty them up and if she aint pulling air your running way too rich rich which = poor power output and high gas guzzling

[C0TT0N]

pulled the air filter off and its spitting out a mist of gas...filter was soaked.

[Aussie Steve]

Hmm... in the old days if a carb spit back it was usually 1 of 2 possible problems...either you had too lean a mix or the timing was way out. If you have electronic ignition it is unlikly to be that so that just leaves the mixture. It could also be float height or a sunken/leaking float.... float height controls how much raw fuel is deliverd to the air entering the carb and thus the mixture.

[C0TT0N]

new symptom.... eating up spark plugs on the right side. aussie can you explain "mix" and what i need to do?

[Clint]

Mixture is a direct result of the condition and adjustment of the carburetors, as well as the fuel and air filters. Any abnormality in them can result in a lean or rich mixture.

[schlutzer]

I have a bike that is very similar to yours and had the problemw ith it killing spark plugs..and not running proper.. I had to do a few things which i recommend you do...granted mine sat for 11 years instead of 5 but this could be a start

first pull the carbs out mine needed more than a cleaning it cost me 60 bucks to get the rebuilt while i did the rest of the work.

you should probably look at your contact points if they are worn replace them...they are located at the bottom of the engine on the right side. you have to remove a circular cover that likely says DOHC

[Aussie Steve]

Mixture is where the air is mixed with the fuel to give a 15 to 1 mix across all throttle settings. Usally the pilot circuit runs from idle to around 1/8 throttle the needle controls from 1/8 to 1/4 and the main jet controls the rest. To alter the pilot circuit you turn the pilot jet screw out to lean it or in to richen it. I am not sure where your pilot screws are...mine and any late model bikes have them blanked off to stop people playing around with this setting something all EPA's require these days.


The next stage is the needle position. Some bikes have needles that have grooves in them and you can lower or raise the needle. Raising the needle gives a richer mix and lowering gives a leaner. Most modern bikes have no grooves but you can raise the needle by slipping shims under the top where it fits into the needle mounting.

Finally the main jet controls the amount of fuel entering the air flow. A larger number stamped onto it means more fuel, conversly a smaller means less.... ergo rich and lean. It is important to remember that the float level also affects the amount of fuel entering the air stream. A too high a level will give a rich mix across all ranges...too low and the mix will be too lean.

Your plugs give a direct indication of how your motor is running. Richness is usually indicated by dry black fluffy carbon deposits. Lean is a dry white and sometimes blistered appearance...depending on the degree of leaness. A plug that is wet and oily indicates a worn engine/bore/valves/rings etc... or in the lucky cases means you are running a plug that is too cold. You are chasing a light tan to brown colour. This is only idicated on the very tip of the plug as are all the other idicators.

To get an accurate picture you must do a plug chop as this is the only way to see if your engine is running too lean or too rich.

To do the chop it is preferable to remove the tank and fit a small tank...I use a mower fuel tank with a filtered tap fitted. This I simply fit to the frame using gaffer tape. Now I have never used this on a modern CV carbed bike so some careful fooling around may be necessary. Take the bike for a run and let it warm up...then give it full throttle for about 1/2 to 1 mile. Cut the ignition and coast to a stop using the clutch...do not change down or slow down using the engine or you will get a false reading. Pull the plugs and take a look...remember they are going to be hot!

Hope this helps and take care where you do the fast run. The plug chop assumes all other components and timing and valve clearances are OK so make sure they are first.

Regards

Steve