Crank... but no start

[bushhead311]

Hey,

I'm new at this posting thing.. I have been using this site and all the great information on it to troubleshoot.. thought I would ask around for some ideas about my 450. I recently aquired a 1987 GS450L with about 9,000 miles on it... great shape all around. However, the bike has been sitting for about a year. The fluids were drained out.. but I'm not sure about completly. I will try and list what I have tested and done.. and what I know.. here goes!

The bike cranks strong but does not catch... pretty much period. A bit of starter fluid will crank it right up... however it refuses to run otherwise.

I have,
Checked plugs, I have spark.
Compression is good.
Tested fuel flow until the point of hitting the carbs, flow is good.
Oil & Gas is fresh
Kill switch set to run
Fuses good

I have checked choke and throttle settings... and played with starting in different throttle settings.. no luck. The throttle is now set all the way shut. Choke full, throttle none.. I get nothing.

I have also performed a wimpy carb clean. By that I mean I took the bowls off and cleaned with air and carb cleaner. It was apperent when I removed the bowls that the carb that was leaning toward kickstand had fluid in it for the year in storage. The fuel inlet that moves with the float was stuck open, I worked it to moving again. Air runs through the main jet however I have not yet removed the pilot/main jets or the needle and seat for cleaning. I have no overflow problems with the bike, but starting it in ON or PRIME produces no results... and it has become frustrating. I am trying to avoid the complete carb rebuild.. but I guess that might be coming soon.

Another strange thing... the last few days when I start the bike cold (as in it has been sitting all day... it actually catches for 1/2 a second) Very brief.. but the only life I have heard without ether. I started noticing this happening after I adjusted the throttle so it sat all the way shut.

If anyone has ideas.. I would be grateful... thanks!

[chiphead]

Clean them carbs bush!! And replace the intake orings and boots if applicable. Search these forums for more info.

[Steve]

Yep, gonna have to pull the carbs and take them apart. You have spark and compression, so the only part missing is fuel. Order the intake o-rings so they will be there by the time you get your carbs done. The carbs are not really that hard to do, just take your time and pay attention to the details. It helps to keep a notepad handy to take notes and make sketches.

Starting tips...be VERY careful using ether. I would even go so far as to say "don't use any at all" as it is too easy to get carried away with it, with potentially disastrous results. When everything is working properly, set the choke somewhere between half and full (experience will determine this, but start with full for now), don't even touch the right hand grip, except to push the starter button, then pull the clutch and hit the starter button. As the engine warms up a bit, you can ease off on the choke. Most bikes will not tolerate any throttle until this point.

It makes me cringe when I hear a bike start on full choke and immediately go to 3-4000 rpm before the oil starts flowing, so I have found the spot in the choke setting where the bike starts easily, but stays about 1500 rpm or so.

Let us know how you do with your carb job.


.

[tkent02]

Probably have to do the carbs....

if you don't have time you may possibly get around it by putting a strong concentration of carb cleaner (the stuff made to go in a gas tank) into the carbs and let it sit a day or two. Mix it with gas and put it in there. it may loosen up the stuff to the point it can run. If so, keep putting it in the gas and most importantly RIDE IT!.
Not real likely to work but it sometimes does.
Depends on what type of crud was in the carbs.

[mark]

Agreed with above posts. You could try starting it and then check your plugs to see if they are wet or not (getting gas). Also at least on my bike when using the choke don't open the throttle at all, or the effect of the choke is basically gone.

[bushhead311]

Update

Hey guys..

Thanks for the advice! Did some carb cleaning today... found the pinhole between the pilot and main jets clogged on one carb! Cleaned main jets and pilot jets... started it up... doing better! The bike catches almost everytime now... only on full choke. Couple of questions... what is the other small thin pole going through the throat... not the one on the actual cylinders ... but the other one... ?? It seems like it is on the verge of sucess... it cranks and catches now consistently but doesn't run/idle... any ideas... what about air screws? Should i mess with that.. my bike has little covers on the access points for them.. i dont know if that would be a problem. Is the problem still sounding like not enough fuel?? Thanks!

[bushhead311]

Success!

I got her running! Thanks for all the advice... turned out to be a clogged jet in the bowl on both carbs... i don't even know what the jet is for it wasen't marked on the carb cleaning series... but there was only one hole in the bottom of the bowls and blowing air through it produced a complete unclog on both jets... anybody have a good suggestion on calibrating throttle and idle screw for good idle. I've gotten it really close.. but it won't quite idle without choke... thanks again guys!

[koolaid_kid]

Try this site on tuning the carbs. It appears that you have Mikuni CV carbs.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

[crusin550]

I've had my carbs cleaned by a mechanic (friend of mine so I know he did the work) and also had the regulator replaced. The bike had been running for a while with a new bat and a bad regulator. Now I have a hard time getting it to start, only been able to do so with it hooked up to a car bat. I'm going to go get the bat tested at advance auto, lookin at possibly gettin new spark plugs as well. Anyone have any other advice on this matter? BTW i had the bat fully charged via trickle charger and would flatline the damn thing tryin to start it.