[Cantankerous]

My friend's GL1500 idles on four or five cylinders and at 1,500 to 3,000 RPM runs horribly. Hard accelleration seems OK, but it won't cruise correctly. He thought it was water in the gas, but ran it totally out and it still does it after a fillup. The local Honda dealer said the carbs need synced, but I've never heard of it causing this much trouble. We replaced the spark plugs (what a pain) and it made no differance at all. Any suggestions?

Please let me know if I posted in the wrong place.

 

[joe in calif]

Could be a vacuum leak, there is a small vacuum hose I think it is on the right side (sitting on the bike) between two of the spark plugs that has been known to break. Could be air filter, or fuel filter or a number of other things. If you have the dealer sync the carbs tell him IF that doesn't cure it you're not paying him.

 

[fossil92]

You could always do a quick compression check just to make sure you don't have something funky going on however I tend to agree with Joe. Vacuum is a beast that rears it's ugly head sometimes.

As far as your comment of where to post. It's no big deal we all just start chiming in but if you look there are categories for engines, suspension, tires, exhaust etc etc etc.

Good Luck.

 

[Cantankerous]

You could always do a quick compression check just to make sure you don't have something funky going on however I tend to agree with Joe. Vacuum is a beast that rears it's ugly head sometimes.

As far as your comment of where to post. It's no big deal we all just start chiming in but if you look there are categories for engines, suspension, tires, exhaust etc etc etc.

Good Luck.

Of course I find the other catagories, after I posted this. I will get with him and check for a vacuum leak. We should have thought of that ourselves.

 

[slickster]

Start with a diagnostic procedure...check compression, check plugs, check firing order, work to get a reasonable idle and pull plugs one at a time to check cylinder balance, can use a temp gauge on the exhaust pipe as it comes out of the cylinder...cold ones aren't working at all....much hotter ones are lean...on to the carbs...COULD be lots of things....more investigation is required.....good luck...Mick

 

[detdrbuzzard]

hows the fuel filter ? did you drain the crankcase breather reservior

 

[drmcmtru]

Since this bike is pretty old now,as far as basics go,i would be taking a look at the timing belts.You mentioned hard accel. is good,so plenty of fuel is getting to carbs.,and you have good spark. When i did my t.belts on my '94SE at 111,000 the right side one came off the gears without touching the tensioner. Before changing them,mine was doing a pretty good stumble on take off,as if still cold with not enough choke. Let us know what you find.

 

[Cantankerous]

Guess I should have let you all know, it ended up being dirty carburetors! Thanks for all the help.