high idle

[dasuchbe]

Okay, thanks to you great people here, I got my xs running again.

Removed and cleaned everything but the slide diapragm on the number 3 carb thanks to a stripped screw. All in all, they weren't too bad. Pre-synced them per the tip here.

Changed the oil and put a new filter in. A Yamaha dealer in the next town west had an after market bolt for the oil filter.

Took out the old plugs and gapped and installed new ones.

After a bit of messing, it finally started. Smoked a bit at first but it went away. Rode the bike a few blocks.

It had a very slight miss but other then that seemed to pull well thru 4 gears.

Main problem now is the idle is sitting at about 2500.

Now if I have figured this right, the choke lever goes all the way in {to the center of the bike} for normal and all the way out {to the left side} for fully choked.

Well, when I choke it, the idle climbs to about 4000.

So, is this a sign that I need to sync. the carbs the right way? {{With the Tuner }} Or is it possible I left the idle set too high. I tried to back it down, but it was hard to reach.

Right now, the bike starts easily. Pulled the plugs out and the look good, a little bit of oil on 1 but it went away.

Any ideas??

[Mike Hart]

You can reach that main idle screw with a screwdiver, put the blade at a knurl on the idle knob, tap the handle. Get the bike fully warm, then turn the idle down to 1100 rpm (counterclockwise, I think).

Or, warm it up good, take off the tank, bike will run on fuel in bowls long enough to set idle.

[xjguy]

Idle

I had a similar issue with my xj after presynching. I realized that even though the throttle cable seemd to have free play, I needed to back off on the nurled nut at the handle bar end of the cable.

I did a preflight on cycle and found i needed to back off nurled nut even more. Otherwise the the RPM'S would hit 3000 when I turned to right.

xjguy

[dasuchbe]

Well, fortunately for me, it was just the idle set screw. Once I got it backed down, everything smoothed out. Now it pulls good from idle til I wimp out and let off. And when I do let off the response is immediate instead of hanging and then gradually letting off.

I went out this morning and started it after sitting all night and after cranking for a bit it finally fired off. It is definately cold blooded, but once this sleeper awakens....

Now I am going to tear into the front master cylinder. I pulled the top off and it was full of rust and water. Pulled the lines off at the calipers and got sludge. So I have no front brakes.

I think I will pull the top off and check the valve clearance and everything else that is under there. I am hoping that this is the source of the smoking I am seeing. It is very slight and usually does not show up til after running around the block.

[TopCatGr58]

Originally posted by dasuchbe
I went out this morning and started it after sitting all night and after cranking for a bit it finally fired off. It is definately cold blooded, but once this sleeper awakens....

Now I am going to tear into the front master cylinder. I pulled the top off and it was full of rust and water. Pulled the lines off at the calipers and got sludge. So I have no front brakes.

I think I will pull the top off and check the valve clearance and everything else that is under there. I am hoping that this is the source of the smoking I am seeing. It is very slight and usually does not show up til after running around the block.

Hey there Dave,
First of all, did you use the choke? Secondly, you might try turning the petcocks to PRIME to get fuel into the bowls quicker, then turn to ON once it starts.

Secondly, good luck with the master cylinder, you can get a rebuild kit to replace the rubber piston parts, they can get chewed up by the rust lying in the tube and the piston sliding in and out over it. You'll probably need to reem out the cylinder.. honing stones but haven't seen them that small to fit that size hole?? As for the calipers, you'll want to be careful when disassembling them, there is a small metal "C" type ring that holds the outer rubber seal on, then there is a rubber O-ring that is around the piston. The piston is steel, and can/does get rusted and pitted a bit, fortunately, the rubber O-ring is what makes the seal, not the side of the piston. You can get rebuild kits for these as well. Fortunately, the caliper housing is aluminum, and so the rust doesn't cause any pitting to occur to it, just clean it out good with whatever solvent you want that is aluminum friendly, then dry it out good. You might need to use some emory cloth on the caliper cylinder walls as well as the pistons. Then coat everything with brake fluid, put on new O-ring's and put back together.

You may have trouble getting the pistons out, folks have recommended compressed air at the brake line inlet or bleeder valve. I just put mine in a vise, then got a big pair of lock jaws, sprayed some frozen nut penetrating lube around the piston, and then I had to take a blow dryer, and heat up the caliper casing to get the piston unfrozen....it had sat for 9 years!!!!!

Lastly(yeah...sorry for long windedness!) adjusting the valve clearance won't do anything for the smoking if it's oil leaking into the engine. It's either coming from around the rings, or past the valve seals from the topend. Darn if I can't remember the details about the bike you posted earlier, but if it has sat for a while, and hasn't really been run at highway speeds for a while, that may be all it needs, to loosen up and burn off carbon, maybe to unstick some rings?? Fix your brakes first, then take it for a decent ride, then assess the smoke. Can you do a compression test? A leak down test is more thorough, but a simple Comp test can tell you a bit about it for now. Let us know how it goes!

PS. were you able to D/L the owner's manual and assemble it from YAHOO?

[dasuchbe]

I am trying to get hold of a compression guage, I figure that will give me a good idea about the engine.

The bike has not been ridden very much at all over the last year or two. If fact I think it has sat most of the time so I like your thought.

I still have to get licensed and insured, but as soon as I do, I intend to take it on a long ride around town. Til I know exactely what shape it is in, I am afraid to get very far away from home. But I am a lot more confident about it right now.

When I rode it yesterday I had the choke in.

Thanks for the info, it will be a week or two until I start on the breaks. They are one of the reasons I have not worried about tagging it yet, it is not road ready.

[skids]

Re: Idle

That is a good idea. Also, make sure that the throttle cable is not binding and is routed correctly. If it revs when turning, it is a definate safety concern. I had on on my xs11 that broke the small tab near the right grip. I didn't know that it happened until I had a runaway idle.

Originally posted by xjguy

I did a preflight on cycle and found i needed to back off nurled nut even more. Otherwise the the RPM'S would hit 3000 when I turned to right.

xjguy