low rpm missing

[big r]

Went to go for short ride this evening and the bike started up just fine, warmed her up and tried to go. Would seem to run on two cylinders until she got up to about 3 grand then cleaned out and ran hard. She would backfire a bit as it came down the range, but would still idle smoothly. Had trouble with the tach. the other day, got that working again, wouldn't show revs over 3 thou. I am hoping that this an electrical issue and not a carb issue. The bike ran flawlessly last weekend and then sat all week. Anybody have any ideas. Almost forget it's an 86.

[big r]

Fired the bike up this morning and she now runs fine no miss or stumble . Fixed itself? I think that there was a bit of something in the gas (water maybe). Just went for short squirt and she ran just fine. Gassed on it at about 4000 in fifth gear and had a major clutch slippage. Guess what I will be doing this winter, only have a couple weeks of insurance left Oct 19 and by then it is just to cold to ride much. Thinking that I might rebuild the carbs as well this winter.

[bluesix]

BigR, I have a similar problem with my 86 1200. I thought I had it fixed and it came back. My symptoms are while cruising at low throttle openings(about 1/8th open) I get what seems to be a cut out in the ignition and my tach jumps. I can apply more throttle and it picks up and drives out of it. Sometimes the tach jumps without the cut out, but when it cuts out the tach is always jumping. I have some pretty large main air jets, 135 I think.It has the pod air filters and a header. I'm going to get the 155 air jets for it and see if that has any effect.

[mickarch]

... My symptoms are while cruising at low throttle openings(about 1/8th open) ...

If your problems are occurring a part throttle, I don't think swapping mains will help.  I think at 1/8 throttle you'd need to look at pilot jets and needle height.  What I've been able to gather here and elsewhere is that the main jets really only control above 3/4 throttle.  I'm sure if I've got that wrong, the more knowledgeable folk here will correct me.

mickey

[yarin]

if it's missing at low revs.  it could be the plug wires arching.  wait for dark to come and see if there is arching to ground/motor while it's sitting.  u can see more with tank off, slid it back some or use auxilliary tank.   inspect the wires for burn holes.  check for a healthy bright white spark.  if it looks dull,  pull your coils off remove cold solder joint and resolder!

tom

[Pat Conlon]

I agree with the above, in addition,  Clean the holes in your emulsion tubes (aka main nozzles):

These little buggers get clogged and weird things happen.
A complete flush and cleaning of the fuel system will keep the tubes clean. If you do not do this, you might have to clean them again.
I have been using StarTron for fuel stabilization : http://www.marineengine.com/products/accessory.php?in=3253032&gclid=CNm1iK68vq0CFcYZQgodWleqAw

[simi_ed]

Paddy, where are you buying Startron?  The only place I found it is WallyWorld.  They are charging ~$9 for a 8-12 oz bottle.

TIA,

Ed

[Pat Conlon]

Paddy, where are you buying Startron?  The only place I found it is WallyWorld.  They are charging ~$9 for a 8-12 oz bottle.

Hello Ed, happy New Year amigo...

At first, I bought it at Ace Hardware (same price as Wallmt) http://www.acehardware.com/product/index.jsp?productId=3506023
In the small sizes you are paying $1.08 to $1.12 per oz. If you get the big 32 oz you end up paying ~24% less at $0.87 per oz.
Subscribe to the MarineEngine.com newsletter (free) and you will get a 20% discount code to enter at checkout. Then if you buy a 32oz'er you will end up paying $0.70 per oz. One ounce will treat a full tank, and what I like about StarTron is, unlike Stabil, that you can not over treat your gas. i.e. add too much StarTron.
StarTron is the best warm weather gas treatment that I've found, and I've tried them all.

Cheers!

[racerman_27410]

Pat,

any bad tendancies using this stabilizer with the ethanol laden fuels we're getting now?

i've known two people now who had some serious green badness happen with stabil and ethanol.


KOokaloo!

[Pat Conlon]

Hi Frank,  (according to) StarTron was made especially for E5/E10/E15 fuels.
I don't know about E85 and I don't know how well (or if) StarTron works in cold weather.
The local Colorado River ski boaters seem to love it. They store their boats with full tanks for 6 months or so...