1-low idle at start 2-bike wont start

[blank slate]

1-Is it normal for the bike to take 5 minutes of me holding the throttle while it idles (2000-2500 rpms) before it's warm enough to go for a drive without dying in neutral? Maybe the carbs have something to do with it because I have not cleaned them yet and I didn't ask PO when he last cleaned them. It's on my to-do list for sure.

2-Today I took the bike out for a 1 km ride, came back home, parked it, and 5 minutes later I tried to start it again and the bike wouldn't start with kick or starter button. It just seemed like the more I tried, the weaker the bike sounded, and the dimmer the lights on the front of the bike shined... If that makes sense. All I could think was that the bike was out of power and the battery was dead. How do I know if this is the case? I have no idea when the battery was last installed. I do have a multimeter for testing the battery if that helps.

 

[gfmiv]

blank slate,

i am experiencing similar problems! the bike, a '75 xs650, was running great all week, weather got a bit chilly and the damn thing wont start! have you gotten advice on what the problem might have been? have you gotten the thing running again? I dont want to take it to a mechanic, i want to fix the problem!!!

thanks a ton!

gfmiv

 

[angus67]

blank, the idle sounds too low. should be 1200 rpm when warmed up. if your idle is too low, that means your throttle plates are almost shut, choking off the air supply.

 

[blank slate]

Hey guys, I got no answer so I, blank slate, who knows nothing about tools let alone how a motorcycle operates, read the crappy haynes twins manual and the superb tech section of this forum looking for answers.

First was charging the battery. It worked temporarily, then started acting up again, so I bought a new agm battery. The starter is full of energy but it didn't want to catch? whats the term i dunno. Then I heard a loud firecracker under the bike and black smoke coming out where the right header/engine meet. I said f this, I'm taking the bike apart.

I'm a new owner who was afraid of going into a bike that ran. Reality is that 37 year old bikes need maintenance and the dealer is too expensive so I gotta do it myself. Wish I could have waited until winter to tinker/update the bike since I just passed an intermediate safety course M2, and wanted to ride a lot in the fall. Instead I'm chasing down parts and doing maintenance.

With that out of the way, I have been buying and installing new spark plugs, new oil put in, new oil filter, cleaned the petcocks, (forgot to mention that I put 94 octane in the bike mixed with 91 that was in there previously so I dont know if that had anything to do with that bang), also took the carbs out which were pretty clean but I put them through an ultrsonic cleaner at my friends place to really shine. I'm only going to bench sync them. Air filters were taken out and soaked in soapy water. They smell great now.

Both tires upgraded to Pirelli rt 66, bought a new master cylinder from mikesxs, need to install that plus bleed brakes, ......

I should get a couple of little parts I'm missing by friday and let you know if the bike runs or not

 

[blank slate]

I'm reading the Haynes manual now, and it says
Symptom: black smoke from exhausts
Cause: carburettor flooding
Remedy: dismantle and clean carburettor. check for punctured float or sticking float needle

so maybe I'm on the right track

 

[richardthemotorcycle1]

Hey Blank slate, I'd say that the choke circuits may be plug, if your using the choke, you shouldn't have to work the throttle at all. has the carb been off the bike and thoroughly clean, and check those pilot jets too.

 

[blank slate]

Hey Blank slate, I'd say that the choke circuits may be plug, if your using the choke, you shouldn't have to work the throttle at all. has the carb been off the bike and thoroughly clean, and check those pilot jets too.

Yep the idle was awefully low. If my throttle wasn't open the bike would die. only after 5 minutes of revving was it warmed up to idle without dying. really annoying.

last weekend the carbs went swimming in an ultrasonic cleaner. When I put the bike back together we'll see if that helps. I'm waiting on a little plastic o-ring that goes around the needle jet to put the carbs back in and fire it up.

 

[blank slate]

Ok so I'm happy to report my bike is alive again. I bought it in august and it was working fine then so I didn't want to screw anything up by tinkering with. I have no mech experience. so when bike died I had no choice but to go in there. this is a list of stuff I've done since it died...

Carbs were cleaned in ultrasonic cleaner
every jet was inspected for blockages and cleaned
Float levels set to manual specs 24mm
O-ring on needle jet z2 replaced
Bench synced butterflies
replaced old wet battery to agm battery (13+ on multimeter now)
oil changed, oil filter and gasket replaced,
new crushed washers for oil plug (forgot to inspect strainer )
new spark plugs and put dielectric grease in plug caps
cleaned air filters in soapy water

This took about 2 months of researching online, ordering parts from dealer, ebay, mikesxs, but I'm much happier with how the idle is now. Shoot, I was thrilled just to hear the bike start!

 

[richardthemotorcycle1]

Glad you got her running again did you find out what the problem was

 

[blank slate]

Glad you got her running again did you find out what the problem was

I'm not sure, combination of all the above. I have yet to clean the electrical harness and all the contacts, but over the winter I may do that.

I'm working with a guy on repairing an xs1100sf and the stuff I'm learning with him on that bike is extremely applicable on my 650.

 

[TwinLewi]

Is it bad to run/ mix 91 with 94 octane gas?

 

[lakeview]

Should not matter. More important is the age of the gas and whether there is ethanol in it.
These bikes really do not need hi octane, but I try to use only non ethanol gas and most pumps only sell it in the highest octane.

 

[TwinLewi]

Should not matter. More important is the age of the gas and whether there is ethanol in it.
These bikes really do not need hi octane, but I try to use only non ethanol gas and most pumps only sell it in the highest octane.

I figured as much. Never heard of a problem with a mix. Just wanted to confirm.

 

[XSLeo]

I try to run at least 91 octane fuel. The ethanol isn't all that good for the carbs but most places that's what you get.
The ethanol fuel often requires a bit of carb tuning to run right.
I might recommend doing a tune up. There are steps to follow,
#1 Adjust cam chain. This is first because if you set timing first then when you set the cam chain the timing can change.
#2 Adjust valve clearance.
#3 Set points gap. If you time it before you set gap, then timing changes when you set the gap.
#4 Set timing.
New plugs is a good idea. Checking the plug wires and caps is another thing. They can be checked with your mutli-meter. The spec should be in your manual.
Doing these steps gets the mechanical parts of the Ignition and valves set right. Once you know these are right the rest will be easier. Ignition and carb issues often have the same symptoms. You know now with good ignition any further problems are carb related.
Now once you get the done you can then proceed to carb tuning.
www.amckayltd.com/carbguide.pdf is our carb bible. If you use this to tear down, clean, inspect your carb, you will have a good idea what's in there. In the guide is a section titled "Tuning For Mods" Even with a stock bike most need a bit of adjustment mostly because of todays fuel.
This section describes test procedures to follow. With the results of the testing you can determine what adjustments your carbs might need. The guide gives tells you what to adjust from your test results.
Make one adjustment at a time. test, make one adjustment test.
Do only one adjustment then test is the best way to go. If you do two adjustments then you won't know which one made the change.
Good luck. You will really enjoy the way the bike runs much better after you are done than if you paid a shop to do it. the satisfaction you get from the job well done will give you pride In the accomplishment.
Leo

 

[Team Junk]

I'm not sure as a general rule but I know some non ethanol fuels replace the ethanol with methanol which is far worse. Something to look into. Federal law requires oxygenated fuel so there is something nasty in there. Before it was banned,MTBE was the cheaper agent. The town of Deerpark Tx where the Ethyl Corp made the crap, stunk with the smell of it because it ate every seal in the plant.