89 1300 a little lean

[frankd]

My 89 is a little lean at light throttle. When I test rode the bike before I purchased it, it appeared to be fine. However, when I started to service it, I found the air cleaner was probably the original and extremely dirty. I installed a K&N and then I notice that if the bike wasn't completely warmed up it would bog a bit at light-medium throttle. If you opened the throttle, it was fine. Idle was fine as was response off of idle. The lean condition was only noticable for a minute or two after you pulled away with a cold engine.

 

The bike has about 37,000 miles on it now, and runs great. I've set the idle mixture and the bike idles's great now. Of course, I've also synced the carbs. Whatever is wrong is on all 4 cylinders because when it bogs, all 4 bog. Of course it tends to fart out the exhaust when this happens also. When I bought the bike it had cut out mufflers. I've replace them with stockers and also replaced the baffle chamber with a known good one. My gas mileage is a touch less than 40 MPG @ 75 mph indicated (72 GPS). When I rode a little slower for a tank, it gave me 46.5MPG. This is with loaded bags and 2 up.

 

 

This morning it was about 55 degrees F. here and the bog was really bad. I believe I need to raise the needles a little, but I see that Mk II's aren't adjustable as the 1200's were. I know everybody else has rich carbs. My 83 was on the rich side. You'd start than one up with a little choke in cold weather. Then pull away with the chock on a bit and turn it off after you were moving. It would run great no matter how cold it was. Not this 1300....Anybody else had this problem or have any ideas?

[Yammer Dan]

I thought the needles were the same. Maybe put a set of eariler needles in there?

[skydoc_17]

Hey Frank,

Because everyone has their own little "buzz word" for a particular condition if we could get some more information from you we might be able to help you. When I think of an engine "bogging" to me that sounds like it is getting to much fuel. If you are not able to "cure" the problem with the choke but it goes away once the bike is warmed up then I think you have an "over rich" condition at startup. To verify this, if your Idle Mixture screws are all at 21/2 turns now, then try 21/4 turns. (Remember not to bottom the mixture screws hard, damage will result) If this shortens the warm up time or you see an improvement in the performance then you are on the right track and you do indeed have an over rich condition at start up. If in fact you have a lean condition, what kind of shape are the Carb. Diaphragms in? You could be sucking air thru a bad Diaphragm. Do a search for the needle shim mod by Five bikes, it is full of information about manually adjusting the mixture of the VR Carbs. I would also like to mention that my 1300 VR motor is a bit "cold blooded" in temps. below 60F. I would be hard pressed to just start mine up and drive away if it was 50F outside. Get back to us with more info or PM me and we will help you thru this, there are a limited number of things to deal with here and we can go thru them one by one.

Earl

[5bikes]

Yes it's me. A bog just off idle is the idle circuit. Above 2k rpm is the needles.

Don't guess, make a change. Just remember, write it down where everything is before you start messing with either circuit.

Idle circuit, screw in/out 1/2 turn to see a difference. Can go back 1/4 turn later. Make sure they are all the same.

Needles: You can richen as well as lean easily. Add 1-2 thin washers under the white spacer and/or circle clip to richen. To lean remove the white spacer and add washers about 1/2 the thickness of the white spacer.

I'm thinking you are lean. High 40's mpg loaded down, is the indicator. Putting in a K&N is another.

I just went back to the washers 1/2 the thickness of the white spacer because my mpgs were in the high 30- low 40's 2 up.

Leave the lower fairings off until your satisfied with performance and MPG.

Learned something new. If there is soot near the plug threads it is rich. Just looking at the 2 electrodes will not be a good indicator. Clean is good but then it is hard to determine too lean. Confused? do a pic and email me at chuckfrench48@gmail.com

Edited September 24, 2009 by 5bikes

[skydoc_17]

Hey Chuck,

Thanks for jumping in there and sharing your info. When ever I talk about shiming the needles I always give you credit.

Earl

[Condor]

Here's my thinking on this. If it only lasts for a couple of minutes when first starting out I'd just control the bog with a partial choke and be done with it. The milage you're getting is nothing to sneeze at. There are guys that would give their left nu....er....leg for that kind of milage....

[frankd]

It's definetly lean, and it's OK just above idle. When it goes a little lean is when you pull out on the main highway (with a cold motor) and roll the throttle on. I intend to checking the carb diaphrams this winter. It's good to hear that other 1300s are cold blooded. My 1200 isn't cold blooded at all, but this 1300 sure is. When I was pulling away from my work parking spot today (70 degrees) I started it up with no choke. It drove away fine, but for the heck of it I gave it about 1/2 throttle after about 3 minutes of running. All 4 cylinders bogged and went completely dead. A couple of cylinders also belched out the tail pipe. In a couple minutes more, it was fine.

[6m459]

Has she had any SeaFoam lately?

 

Brian H.

[mbrood]

Have you pulled the plugs recently to see what they look like? Is she synced?

[frankd]

Yes, she has been synced. No idea how old the plugs are, but as of Thursday there's a new set in the saddle bag. I know she needs plugs and I'll put them in this week if I get a chance. I'm out of town now (car trip) and should get home Monday.

 

Frank

[bobcat]

No Biggee....My 86 is cold blooded also...I usually let it idle for a good couple of minutes before taking off...