Another Carb thread...

[PuyallupValk]

Hi, everyone! Mike and Denise Parker from Puyallup, WA here saying 'hello' to the board! We recently picked up a 1999 I/S...55K miles...grn/slv...beautiful bike and we're excited to have her!

I do have a question...the previous owner said the carbs were cleaned and sync'd just 3K miles ago, however the bike sat for the most part of the past 2 years. She idles a bit low (like 500-700) and from idle if I give her some throttle, she'll sputter and die. If I ease into the throttle the rpms will pick up nicely. I've added some STA-BIL to the fuel and have been running her at the problem rpms as much as possible. It's improved slightly but the hesitation is still there for sure. I did advance the idle adjustment just a bit as she was idling at just 1200 at full choke. I've got her at 1500-2000 now. I've read LOTS of carb threads and I'm pretty sure the pilot and low jets are the issue. Soooo...should I stick with the fuel additive for a few tanks or is 2 years of varnish too much to dissolve (meaning I should have the carbs serviced and be done with it)?

Also, any recommendations for carb servicing in the Pacific Northwest?

Thanks!

[Bighead]

I would run a rew tanks at low rpm with additives. Before I tore them out again. But that is just me.

[luftkoph]

Is sta-bil a cleaner? Maybe something a bit stronger like berrymans B12. They are tiny jets, and they are only feeding a 250cc cylinder.

[shadowmagic]

I ordered some of this gumout cleaner after watching this video and after having tried redline. Watch the video, its only 3 minutes long but it made sense to me.

https://www.youtube.com/watch?v=gg9ppeUMpK4

[Timbox]

PuyallupValk

I don't know your background working with CV type carbs?  I can tell you that these carbs are really kinda of a cake walk to work on compared to a lot of the inline four bikes of the same time frame.  If there are issues with the carbs I always tear them down.  Making sure you can get them clean and take the carbs out of the trouble shooting checklist is important to me. 

Depending how plugged they are, no additives will unplug some of the jets in there.  Might have to use high pressure air and very think wire to get the crud out of them.  If the PO used ethanol gas and it sat for two years those things could be green inside.  There are some great vids on Youtube for taking them apart and what to look for. 

Don't just spray them with carb cleaner, the cleaner might touch some of the rubber in the cabrs and that will make it swell and deteriorate the "0" rings in the fuel rails.

Good luck.

[indybobm]

The best carb cleaner for me is Chemttol B-12.

[da prez]

  Ditto on B-12.  It may be a band aid , but could get you thru the season. Use a strong dose. Run the bike for 20 to 30 miles and let it sit overnight. B-12 will dissolve a lot of crud.   If no improvement , then a rebuild is in your future.
IF YOU re-build , do not do the first start up in the garage. Have a fire extinguisher or hose handy. Use an IV bottle for a fuel source.  I bought two (different) bikes where the owner rebuilt the carbs and started in the garage and they caught fire.

                                                            da prez

[yrunvs]

I have a buddy whom I respect for his motorcycle knowledge that recommended this stuff. Has anybody here tried it?

[Timbox]

Just watched a few vids on youtube and that product ^^^ does not seem to work as advertised.  It could for some, but not just add and go.  If a set of carbs is really plugged and has residue in the float bowls not much will really help besides to that the residue out manually.

[yrunvs]

Yea I took my carbs off a couple months ago and (thought) I had cleaned everything but I'm afraid I could have done a better job and will need to re-do it. I was hoping since they (carbs) were mostly clean I could run some magic liquid through to flush whatever is left out but I suppose that's just a dream and I'll have to take them off and do it right (the second time).

PuyallupValk.....The moral of the story is there probably is no liquid magic to clean the carbs out and so do it right the first time by pulling them off the bike and breaking them apart and installing new jets and checking the air cut units and flushing the fuel galleries or there will be a second time. 

[h13man]

1/2 can of Berryman B12 or Seafoam to a fresh tank of fuel. Used Gumout on a dirty 67' Plymouth carb and worked within a few miles and never had issue after that. A strong dose regardless works best.

[rug_burn]

   I hate to say it, but:  IF ONLY all that stuff did what they claim it does....  
As previously stated above- when the carbs are seriously gunked up, there are really no shortcuts- you just gotta pull that carrier, pull 'em all apart, clean everything and replace all o-rings, including on the fuel and vapor rails, check and probably put on new vacuum lines.   And don't forget the ones in the diaphragm, at the needle base, and clean off the needles while you're there.
    But after you do it once, you'll have gained a lot of knowledge about that part of the bike.  Even though you'd probably just prefer the bike would run good without all that work...

[PuyallupValk]

Hey! Just following up...I used the Berryman's B12. About 1/2 bottle to a full tank...ran it in the problem zone for around 1/2 hour then let her sit for a day...then ran her again...no improvement. So I said "screw it" (well, it wasn't 'screw'...lol) and poured the rest of the bottle in there...repeated the 30 minutes/day of rest and VOILA! She now idles better and has no hesitation off-throttle when fully warmed up. What a difference...even sounds better at higher rpms...and smoother. I did play with the idle adjustment screw a bit as well...she's right at 800rpms now...but again, ZERO stumbling/hesitation off idle. YAY!! Thanks to everyone who pitched in their knowledge!

[gordonv]

Thank you for the follow up, nice to know it worked, and now you're happier with the bike.

I start the riding season off with 1/2 a bottle of B12 when I fill my 1st fresh tank of gas. You may also wish to try a different brand once in a while, or stick with filling with Chevron, and see if it changes any more of just keeps it the same.

Enjoy.