So I get about 16 mpg . . . .any guesses? Help?
#1
So I get about 16 mpg . . . .any guesses? Help?
Well. My GS is really starting to bother me. I am lucky to hit 50 miles on the tripmeter before I have to switch to reserve. Any other person riding a gs gets at least 50 miles per gallon. I am tired of payin out the *** for fuel almost every other day. I want it fixed. The only problem is . . . . I dont know what is wrong. Neither do any of the shops. Thus, I rest my fate in the hands of you guys. Well, lets get this diagnosis going . . . . The carbs were cleaned less than a month ago. The air filter needs to be replaced pretty badly, but Im sure thats not the source of the problem. The left cylinder still has a VERY weak spark, even though I replaced the coils less than a month ago. When I replaced them, I swapped the coils between the left and right cylinders to see if the problem carried over with it. It did not, the left cylinder still had a very weak spark. When sitting at idle, I can completely remove the left spark plug wire, and, GASP! NOTHING CHANGES!! But, if I remove the right plug wire, it cuts off immediately. Yet, it still has power at high rpm, as if the left cylinder waits until after 4k to start working. It smells like gas after riding only a few miles, which leads me to beleive the left cylinder is not firing completely and is flooding, or something like that. It does backfire, especially just after heavy acceleration, but I beleive that has more to do with my 'custom' exhaust than any engine problems. SO . . . . what do we think? Electrical issue, relative to the weak spark? Compression issue? Its a piece of **** and I should sell it before it gets worse? Thoughts, anyone?
![banghead](https://www.stuntlife.com/forums/images/smilies/banghead.gif)
#4
Re: So I get about 16 mpg . . . .any guesses? Help?
Between the weak cylinder and the custom exhaust you have that wont do you any favors. Lack of back pressure and a already weak cylinder doesnt help fuel mileage at all. I say hone the **** cylinder, new piston and rings and see what it does, as well as a new air filter. My sleds do the same thing if the rings start to go on it. If that doesnt help sell the bitch!
#5
Re: So I get about 16 mpg . . . .any guesses? Help?
1. fuel gremlins stealing gas for the white queens power sled?
2. fill the tank up completely instead of 1 gallon at a time
3. replace all plugs
4. compression test
5. put the dam thing on a stand and run it a while n see if gas starts dumping to the ground
6. fuel return hose?
7. change air filter for kicks
8. float bowl needles?
9. rectifier? (i think ur bike has one even though carb'd)
its an elevtrical problem, get the voltage tester out n do work son!
2. fill the tank up completely instead of 1 gallon at a time
3. replace all plugs
4. compression test
5. put the dam thing on a stand and run it a while n see if gas starts dumping to the ground
6. fuel return hose?
7. change air filter for kicks
8. float bowl needles?
9. rectifier? (i think ur bike has one even though carb'd)
its an elevtrical problem, get the voltage tester out n do work son!
#6
Re: So I get about 16 mpg . . . .any guesses? Help?
I dont know how your bike will idle if its a twin and one cylinder doesnt fire at idle. You kinda answered your own questions here man. Your pumping fuel through a cylinder and its not being burned. Then your other cylinder has to work twice as hard, do that math....
#7
Re: So I get about 16 mpg . . . .any guesses? Help?
pull the plugs and check for spark, the plug can be bad, i had a plug go bad at 900 miles, the fuel was turning to oil and dripping out the header mount
if you don't know how to check for spark: pull the plugs, attach the coils, ground the plug to the frame/engine and crank it, you might want to shut off/stop the fuel supply, if only one works then switch the plugs and test again
if you don't know how to check for spark: pull the plugs, attach the coils, ground the plug to the frame/engine and crank it, you might want to shut off/stop the fuel supply, if only one works then switch the plugs and test again
#8
Re: So I get about 16 mpg . . . .any guesses? Help?
pull the plugs and check for spark, the plug can be bad, i had a plug go bad at 900 miles, the fuel was turning to oil and dripping out the header mount
if you don't know how to check for spark: pull the plugs, attach the coils, ground the plug to the frame/engine and crank it, you might want to shut off/stop the fuel supply, if only one works then switch the plugs and test again
if you don't know how to check for spark: pull the plugs, attach the coils, ground the plug to the frame/engine and crank it, you might want to shut off/stop the fuel supply, if only one works then switch the plugs and test again
#9
Re: So I get about 16 mpg . . . .any guesses? Help?
its not that the cylinder is firing weak its that the cylinder isnt firing at all. you need a compression test. i work at a suzuki dealership and see twin cylonder bikes like this all the time only firing on one cylinder and its either not getting fire or its not burning what it is getting due to low or no compression.. id get a shop or someone who knows what they are doing to recheck your coils and do a compression test. you should notice a significant lack of power on the low end of the rpms and running like **** on idle.
#10
Re: So I get about 16 mpg . . . .any guesses? Help?
it is a '95 model. I bought brand new coils from the dealer, almost $200, and it didnt change ****. it has NO power below 4k. none whatsoever, even at wide-open-throttle. it will LOSE speed until it bogs down and dies. I have to cruise at 6-7k to stay moving, but it IS powerful above that point. If it was compression, it would run crappy throughout the entire rpm range, right? it idles just fine, it will sit there and idle all day long. but to launch, you really have to keep it above 5k if you want it to move at all.
Last edited by redhenracing2; 06-22-2009 at 12:03 AM.
#11
Re: So I get about 16 mpg . . . .any guesses? Help?
well essentially if theres enough spark to jump the gap then that cylinder should fire. Okay your getting plenty of fuel it seems....so your left with 2 things.....spark and or/compression...
#12
Re: So I get about 16 mpg . . . .any guesses? Help?
I dont know that the spark is jumping the gap on the plug. I used the old 'screwdriver' method, shoving it in there and then holding it close to the head. it put off a light yellow spark, instead of the 'healthy' blue that it should be. I did this on the right cylinder as well, and got a blue spark over there. how do you test if it is jumping the gap?
#13
Re: So I get about 16 mpg . . . .any guesses? Help?
obviously its a combination of things.. but you say it eventually bogs and dies at full throttle?
carbs need major adjusting.. POS is probably running rich as hell... so rich that it makes the combustion suck
carbs need major adjusting.. POS is probably running rich as hell... so rich that it makes the combustion suck
#14
Re: So I get about 16 mpg . . . .any guesses? Help?
your motors blown , it can be blown and still run so that could be a problem , then ud probably have to hone it and rebuild the bitch and then its not worth it so sell it... a bad motor can lead to burnin a lot of gas
#15
Re: So I get about 16 mpg . . . .any guesses? Help?
could a base gasket leak be related to this in any way? I was told that was where my oil is leaking from, its a very slow leak, takes about three months to get from the top line to the low line. any relation? I dont even know what a base gasket is. where is my base gasket?
#16
Re: So I get about 16 mpg . . . .any guesses? Help?
could a base gasket leak be related to this in any way? I was told that was where my oil is leaking from, its a very slow leak, takes about three months to get from the top line to the low line. any relation? I dont even know what a base gasket is. where is my base gasket?
lmao, is this a joke? just a few posts back you said you were a mechanic but not good with motorcycle electrical problems. You cant judge a weak spark by a screwdriver.....thats like puttin your finger in the cap of each plug wire and tryin to figure out which one stings the most. FYI a base gasket is at the base of the cylinder where it meets the cases. dood you keep answering your own questions. If your told you need a base gasket cuz your oil is leaking from there then it shouldnt be that hard to figure out........
![banghead](https://www.stuntlife.com/forums/images/smilies/banghead.gif)
#17
Re: So I get about 16 mpg . . . .any guesses? Help?
lmao, is this a joke? just a few posts back you said you were a mechanic but not good with motorcycle electrical problems. You cant judge a weak spark by a screwdriver.....thats like puttin your finger in the cap of each plug wire and tryin to figure out which one stings the most. FYI a base gasket is at the base of the cylinder where it meets the cases. dood you keep answering your own questions. If your told you need a base gasket cuz your oil is leaking from there then it shouldnt be that hard to figure out........![banghead](https://www.stuntlife.com/forums/images/smilies/banghead.gif)
![banghead](https://www.stuntlife.com/forums/images/smilies/banghead.gif)
2. Even the shop that I took it to tested the spark by screwdriver at first. When he said that wasnt quite as reliable, he put the plug wire on some kind of little contraption that was like a block of wood with nails in it to imitate the gap of a plug. Same result.
3. I am an AUTOMOTIVE mechanic. I work on Hondas all day long. Cars dont have 'base gaskets'.
4.You really cant tell where the oil is coming from, because everything is so tightly packed on this small-*** bike. The shop that inspected it knows because they are the ones that took it apart and checked it out. I personally think that the oil is coming from somewhere up top (is it called a valve cover on a bike?) but they are the professionals.(obviously).
5. I appreciate the help, but my tolerance for smart-*** responses is getting low. Please, humor me. This is my only means of transportation, and I need this addressed as soon as possible.
And you still didnt answer my question, could the base gasket be a source of compression loss? Since it is below the cylinder, that would be a NO, right?
Last edited by redhenracing2; 06-22-2009 at 01:05 AM.
#19
Re: So I get about 16 mpg . . . .any guesses? Help?
u work on cars right? so lets wise up for a sec.
1. how do u normally test spark on ur honda?
2. if ur leaking oil at th valve cover gasket itll be above the headers or lift the tank
3. like thomas said check ur carb adjustment
4. if u aint done a dam compression check then how do you know compressions low?
5. no the base gasket aint ur problem if one side runs great and the other dont
youve been humored a grip about legitimate posibilities. however, ur sparks weak its in the dam electrical not the motor itself. not being able to read is a joke, so *** it all and read the bold first. its your electrical if ur sparks weak!
no more dumb questions til u try the smart answers. you dont like the help u get then take ur questions somewhere else!
1. how do u normally test spark on ur honda?
2. if ur leaking oil at th valve cover gasket itll be above the headers or lift the tank
3. like thomas said check ur carb adjustment
4. if u aint done a dam compression check then how do you know compressions low?
5. no the base gasket aint ur problem if one side runs great and the other dont
youve been humored a grip about legitimate posibilities. however, ur sparks weak its in the dam electrical not the motor itself. not being able to read is a joke, so *** it all and read the bold first. its your electrical if ur sparks weak!
no more dumb questions til u try the smart answers. you dont like the help u get then take ur questions somewhere else!
#20
Re: So I get about 16 mpg . . . .any guesses? Help?
I only questioned compression because it was brought up by someone else on here, several times actually, and seemed somewhat well-based. My question is, what, specifically, should I be looking for/testing within the electrical system?