Fuel issue with 1 and 2, but it's not that easy....

[Incubus]

It's been a ling time since incubus gave me any problems. It was a bulletproof ride for three years. But I got a new job at the end of last year and my riding and wrenching time were reduced to almost zero. My bike was out once this year, in January, for a 120-mile round trip. Ran fine then, but the idle was crummy. It sat for about three months before that ride and has sat since.

So this weekend I decide to fix it. I pulled the carbs yesterday and cleaned the main and slow jets (all the slow jets were were clogged) and cleaned out the enricher circuit tunnel on the bowls. Then I got ready for a ride.

Well now the idle is real crummy. I checked the pipes and one and two were cool. Easy, I figured. That's clearly a fuel issue. So I checked the petcock. I got flow when I put vacuum on it when in "on," and also flow on prime. Then I checked the fuel line routing, then replaced the fuel line and fuel filter (mounted vertically). No dice. The fuel filter did not seem to be filling up, so I pulled the drain plug from carb no. 1. There was fuel in the bowl. I put the petcock on prime and fuel flowed easily from the drain hole on the carb.

So what can restrict fuel flow is the line and petcock seem to be OK? Anything in the carbs or messed with with you mount the carb is fair game. What can I try to narrow down the search parameters? I could easily have messed something up, but I am at a loss right now what that could be.

For what it is worth, the plugs on 1 and 2 appear fine and I got good spark when I checked them. I get good puffs from the plug holes when I turn them over, so it does not seem to be a sudden catastrophic loss of compression.

Thanks, y'all.

Patrick

[BA80]

Make sure the vent for #1 and #2 (same vent) is clear.

[Incubus]

Well, that was simple. I do not know why I couldn't see it.

I disconnected the breather line from the air box, took the drain plugs out of one and two carbs and blew a little (light) compressed air through the line. After a couple seconds I got air flow through both bowls. Put the plugs back in, left the line disconnected, turned on prime and watched the fuel filter fill right up. I am not sure if the clog was in the carbs or the line into the airbox. The hoses themselves were replaced along with the vacuum lines and fuel lines when I pulled the carbs.

It is funny where corrosion can pop up when you let a bike sit. I hope all issues are solved when I try to start it. Yeah, drained the battery messing with it. I am pretty sure I would have needed to clear those slow jets anyway.

Thanks, Greg.

Patrick

[BA80]

I don't like being the devils advocate but you should probably pull the bowls off those carbs and clean them. Whatever was plugging the vents is in there now.

[Incubus]

That is a solid suggestion, Greg. I know I can get no 1 off without pulling the carbs. Pretty sure I can get 2 off. I replaced all the screws on my carbs with socket heads just for this type event.

Hell, I might pull them anyway. I missed my garage.

Patrick

[cywelchjr]

If there is gas in the bowls just draining them will probably be good. I would probably fill and drain them a few times to be sure, you might be surprised how much stuff that can flush out if it's just in the bowl.

[Incubus]

Sadly, Cy, it has not been that easy. I was premature hen I said flow was restored. It was not. I think it flowed only until air pressure equalized. Then stopped and would not restart. This is annoying.

I pulled off the vinyl tube and stuck a thin circular file down the air tube. It was clear. I pulled carb bowl no. 1 and blew air through the line. Hard. There was no obstuction and nothing came out. I can't get bowl no. 2 off, so I figured the rack has to hit the bench again. I am not sure, though, what to look for. That air vent appears to be clear. At least to no. 1, so it should fire on that one. But noooooo.

When i ride it thall cour carbs seem to hit above 3,000 rpm. At least I get good acceleration. But like I mentioned earlier in the thread, I have had no time to ride for seven months, so it may not be what I should be getting.

I idled ran the bike last night just high enough to keep it running, but low enough to get the full bad running effect. I turned it off and checked the temp on the headers. Nos 3 and four were at about 390 F. One and 2 were at 180 F.

I can think of nothing but carbs and fuel flow to explain why 1 and 2 are the problem. I would suspect snapped camshaft, but I still have compression on 1 and 2.

The cabs come off this weekend. I will check the vent, but I am open to other suggestions as well.

Patrick

[Rasputin]

I guess I have to ask... is 1 and 2 running rich at that level of idle or is 3 and 4 running lean? Those temps suggest rich at 1/2 and leaner at 3/4. The other thought that comes to mind is the three small holes in the top of the carb bore near the idle air mix screws. I have seen a couple of these plug and stuff just does not want to work right. JAT

[Incubus]

Those holes will get a good look this weekend, Rasputin.

My interpretatin of what I am seing is tht 1 and 2 are not firing at low rpm I think those two are kicking in at higher rmp because the vacuum gets high enough that it is able to suck fuel out of the carb. This could be bad equalization or just low fuel flow leaving the fuel level in the carb too low.

Alternately, there is completely different problem and those two carbs both have it. These are the low carbs. I have no centerstand.

I did check the floats last weekend. They were so perfect that I think magic elves must have slipped in one night. My carb skills usually produce lesser results.

These are pretty much random thoughts. I am still at the pondering stage.

Patrick

[WMarshy]

While your in there, pull the emulsion tubes out and make sure all the passageway ways are clear.

[jwhughes3]

Payback

Patrick its good to see you back on, but its karma for not coming to Mom rally

John

[Incubus]

I was going to come, John, but I thought it would be on ROT rally weekend. I checked on the Tuesday after Memorial Day. Guess I was away too long.

[jwhughes3]

No worries

We missed out on the Austin portion as Keoki had to make an emergency last minute run to Albuquerque to put out some fires. (btw they are still burning!)

So we still need an Austin ride some Saturday.

Might have to go thru on a trip back north to OKC or Arkansas.

John