Pilots plugged up on me

[L J VFR]

Well, I have never had it happen until this weekend.  I went to start the bike and it would not. If I held the starter it would act like it was hitting until I released the starter button. I pulled all plugs and grounded them all and I got fire from them.  Put plugs back in and let it sit for an hour.  Went inside and prepared to pull the carbs and when i came back outside decided to try one more time. I put my throttle at half, no choke, and hit the starter button.  Pop,pop, pow. Hmm, something different. Tried again and she fired off, backfiring out of RIGHT side exhaust. Once running I kept her at around 3000 rpm and it finally cleaned itself up.   


The only thing I can think is when I parked my bike last, it was on reserve. I am only about 3 miles from the nearest gas station and I had to switch over to reserve about 2 miles from the house.  I just planned on filling up when I made my trip back to town.  I'm wondering if the low level of fuel had something to do with plugging up the jets?  Maybe some setimentation that normally wouldn't do anything until low fuel?  The bike gets started every week and it didn't do this last week.

Thought I would share this info with everyone.  What's you guys take on this??

[hootmon]

Sounds like it's time for a few doses of SeaFoam...

[lragan]

Lance, I am going to venture a guess based on my experience in fueling and flying light aircraft.  If it had been a while since you switched to reserve (several days or weeks of diurnal temperature shifts, especially in high humidity), then you had water in the fuel.  The fuel pickup for reserve, is of course, lower in the tank.  If you get water, it will flow through the reserve pick up before it gets to the regular pickup.  You can have water accumulate over months if you never switch to reserve, and you won't know it until the reserve is activated.

Cure is to never leave the bike with much air in the tank.  I always fill up at the nearest gas station to my home, so the tank is nearly completely full.  That way there is not much "breathing room" for the system to inhale and condense water.  The inclusion of ethanol in the fuel supply in major cities has, in my view, one big advantage, and that is it will absorb water and feed it through the engine in a very small, continuous stream, mixed with the gasoline.  In this manner it is virtually harmless.

Back on the farm, we would add a little ethanol to the fuel tanks whenever our equipment had been sitting for more than a month, precisely to alleviate this problem.

May not be the issue, but it sounds to me like this is it.  I doubt your low speed jets are clogged, unless the bike has been sitting for a very long time.

[hootmon]

Lance, I am going to venture a guess based on my experience in fueling and flying light aircraft.  If it had been a while since you switched to reserve (several days or weeks of diurnal temperature shifts, especially in high humidity), then you had water in the fuel. 

If this is true, then should he try to drain the bottom of the bowls of the carbs to make sure there is no water sitting there?? Just a thought.

[lragan]

If this is true, then should he try to drain the bottom of the bowls of the carbs to make sure there is no water sitting there?? Just a thought.

If it were my bike, I would take this step.  Not that tedious.  I would catch the drained stuff and inspect for particles, particularly of rust.    I would also look to fill up, if feasible, with a 10% ethanol gasoline. 

[L J VFR]

Thanks for the replies everyone.  When I got home it started right up yesterday from work.  I don't know but I'm gonna guess that it was water. Does seafoam disperse water or do I need to look at something different?

[hootmon]

Does seafoam disperse water or do I need to look at something different?

Per the bottle:

cleans injectors
cleans Carb Jets
Fuel Stabilizer
dries fuels and oil
frees lifters - rings
carbon cleaner
upper cylinder lube
de-icer anti gel

[L J VFR]

One important thing I did fail to mention is that I did have Stabil in that tank of gas.

[tmds3]

I also had stabil in my tank of gas, but I am going to have to pull the carbs and clean the jets. Now granted mine has been parked since March, but according to them this should not happen.

[Greg Cothern]

What typically happens with slow speed jets, in your situation, that you have cleared some out and with the engine heat it helps out.  IF you let it sit then  it will compound the situation.

SEAFOAM, OR pull and clean them hehehehe.

[Lurkin]

I have to pull mine off and clean them too.  Mine hadn't been run for 3 months (July-Sept) while I had a hip replaced.  Before I went under the grinder, I had fueled up and put a double dose of Seafoam in, then ran it for 10 miles or so to work it through.  I then drained the carbs.  Figured this would be good enough since we're only talking about storing it over the summer months.

Started it up in Sept, and it started right up, nice.  Went for a ride, (after 3 months without, felt really good!) but it didn't feel quite right.  Figured it was just a little clogged up.  I ran that tank and 2 more tanks through with a double dose, but it's still not quite right.  It's stumbling at about 5k (have 105 jets and the extra shim) and hates to start when even close to cold.

I'm going to open mine up sometime soon and swab the decks out.

Rod.

[L J VFR]

I lucked out on mine I guess.  I'm still not convinced though that it was pilot jets plugged up.  I think it could have been water in my gas.  I added some heet to the tank yesterday and let it run. 

[Charles S Otwell]

On the subject of pulling and cleaning carbs, for those of you that know my cousin Ron in Celina, Ron was having trouble with idling and taking off, so I pulled his carbs yesterday, he has Vance and Hines exhaust and a K&N filter. I got to tell you they had to be some of the dirtiest carbs I ever pulled the bowls were full of a fine silt and there were pieces of what appeared to be little pieces of pink looking foam about the size of a pencil eraser. I picked them out and when I touched them they turned to a greasy gritty sticky goo (sorry don't know how else to describe it). The idle jets are stopped up and I don't see how the bike was running. The K&N filter was heavy with oil and the oily residue was very sticky. I run K&N filters on cars with excellent results, is this normal for K&N on motorcycles? Can too much oil be used or the wrong kind? It might be a lot of trouble but if I ever change a filter and it's very dirty I'm going to clean the carbs before I waste money on another filter and definitely going to check the fuel for trash. I'll post some pics if i can get a close enough shot of the trash in the carbs. Anyone run into this gummy kind of mess?

[L J VFR]

This is good info Charles.  I haven't ever had that in my carbs, not saying it's not there now though.  Sounds like the k/n filter he has either had too much oil put on it from the factory, or someone put too much oil on it. I do have a k/n filter as well. I will say though if I had it all to do over again, I wouldn't of discarded my stock filter when I put in my k/n.  The k/n flows so much air that it is hard to get the jetting exact. 

[Chad in Michigan]

I posted on another board last week about what i think hppens with the K&n filter. don't know for sure if i am right, it's just my take in it after messing with the jetting on my bike. about the discussion, someone thought this person's problem was clogged main jets. He had a stock bike with a k&n air filter.  about the stuff in the carbs that was found: it could have been the secondary air cleaner element, which can and does break up and get sucked into the carbs. i would look to see if there is still a filter in there. it is located on the left side of the bike, under the chrome plastic cover under the tank. it will be in a little black box with a hose attached to it.



17264.5 in reply to 17264.3 

It's not a clogged main jet. it's the pilots. For the people that have had problems with just upgrading to a K&n filter, it's most likely the pilot jet size. My theroy on it is the k&n filter not only flows better at high rpm's, it also upsets the the 'balance' or the pulses of the carbs from the 90-270-90-270 timing, and is a little leaner because of it. One carb plays off the pulse of another.

the paper filter probably has more restriction at lower rpms and a little more back pressure to stabilize the pulses. just try to start or idle your bike without the air filter on it. it is almost impossible to even get it started.  I had the same problems with my bike, but i wanted to track it down and fix it, spent a lot of time on figuring out and theorizing what was happening. as soon as i added the bigger pilots, things started picking up. at the same time I added 108 mains, and tried various settings of the air/fuel mixture 'd' screws. I'm pretty sure that the pilots did the trick for off the line performance from a dead stop to WFO. if it hiccups aroundd 5-7k then i'd add a shim on each needle, and if it seems a little lean up top, go with 105 or 108 mains depending on where you are located (elevation) These are just my thoughts based on what I experienced when tuning my bike on the butt dyno from the last few years.



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