Lunch Bag Let Down ... She Didn't Fire Up...STILL NO START ??

[79XS11F]

OK .. I rebuilt both fuel petcocks this mornings and tested them. Both are working well. No gas except in the prime position.
When i primed the carbs I got gas out the air filter so I do know that the carbs will have to be re & re-ed to see what caused that. Aside from that I got NOTHING but a sort of wet fart backfire a few times. It didn't come anywhere near firing up.
So I know it's getting gas even if too much at the moment. Pick up coils are new, engine run last year so this is most likely a fuel or electrical issue.
I'll keep you posted and feel free to offer up advise so please do.
Rob

[wingnut]

I have noticed that when I pull the carbs off of a bike and have been mucking about in the fuel bowls or when they have been sitting dry,floats full down, that the first time I put fuel to them one of the float will stick and I'll get a mess. This has happened even on the bench test rig. A light tap on the offending bowl will set it right 9 out of ten times. The tenth times have been when I screwed somthing up during the assembly. Its worth a try

[79XS11F]

Thanks for your input Wingnut. I decided to take the day off and enjoy the day and "regroup" tomorrow. I will take it from the top so to speak. So ... off with the valve cover to confirm that the valve timing is good. Test the coils, check the plugs, confirm ignition timing and check pick up coil gap. If all that stuff checks out I will run the fuel tank from the bench and see which carb or carbs is flooding and try the tapping on the bowl thing in case a float is stuck. If flooding can not be cured that way I will remove the carbs and open them up to see what the heck (read as the "F" word) is going on with them. I will also double check the petcocks and take it from there.
Rob

[John]

A little tip on the flooding on initial filling of the bowls...There is a tang on the flat pivot section of the floats that will limit the drop of the floats when the bowls are dry. If you hold the carbs upright with the bowls off, look at the float pin towers and notice the small brass tang that is resting on the tower. That tang can be bent to limit the drop of the floats, and that will eliminate the float needle from dropping and cocking in the seat and flooding. To determine which carb it is, just remove the bottom of the airbox, set the bike on the center stand, turn the fuel on, and just look up at the carb tubes, and to see which one the fuel is dripping from.

[79XS11F]

OK .. I checked spark and I have strong spark across the board but compression is OFF even as compared to the last time I checked it. I got 150 to 160 on #1,3 & 4 but only 50 on #2.

I added a bit of oil, spun it a few times and managed to get it up to 70. Should I assume that it was #2 carb that flooded and in doing so washed the oil out of the cylinder? OR should I just pull the head and check things out?

Last year when I received this bike the compression was 150 to 160 across the board. I use it for the bulk of the summer and then switched out the engine for the 1179 one. I put oil in the cylinders and stored the engine in a heated garage. I have turned the engine over a few times since then. i can't see the compression dropping that much for the sake of 10 months storage. GGG when I got it it had sat for 10 years.

[79XS11F]

All righty then ... I just attempted to prime the carbs with my fuel tank on the bench and not one drop of fuel came out of any of the intake boots.... Thats because it was more like a STREAM of fuel at both #2 and #4. Tapping on the bowls did not correct the issue so it's off with the carbs.
QUESTION ... Is there any sure fire end all fix for the blasted floats on these carbs?
Rob

[TopCatGr58]

Hey Rob,

You had/have the valve cover off, did you check your valve clearances?? After a summer of riding, could have gotten some wear, as well as IF the clearance was too close, could have burned the valves on that cylinder, etc.? You got minimal increase with oil, so that points more towards valves. I'd check the clearance, adjust as needed. You may also be able to remove some built up carbon from the valve seat thru several techniques that have been posted and done with good results.
Just trying to save you from pulling the head if you don't really have to!
T.C.

[79XS11F]

Hey TC. I only put about 250 miles on it that first year and NO I really don't want to be pulling the head unless I have to. Given the results on my last carb priming test I am guessing that fuel has washed the oil off the cylinder walls and had an effect on ring seal. I will know better after get this carb issue sorted out. Once the bike id running I will test the compression again.

Rob

[79XS11F]

Will I bit the bullet and installed new plastic floats. I had them in my "for the hop up bike" boxes.
I also noticed a "click" when I pushed down on 2 of the float valves. I switched them out to the ones that were on the bike when I got it so not more "clicking" sound. With carbs upside down I can not blow air past the valves so they appear to be sealing good.

QUESTION ....

I will guess that when I set the float heights it will be done to the top of the rounded part of these plastic floats???

Rob

[LoHo]

Did you replace the stock needles with ones that have a keeper? I had a similar problem, and removing the keepers has solved it. It even worked on my 1968 Malibu, which flooded every third start or so, after its rebuild.

[79XS11F]

I'm not sure what you mean when you say "keepers"? I replaced the needles but only the needles. The rest of the setup and method of installing the needles is stock.

I have as I was saying installed plastic replacement floats and adjusted the height of each one to as close as I can to the 25.7 +/- 1 MM level. They now are all between 25.42 and 25.54 MM. I used a digital caliper to to check and adjust them. This was done as per the manual from the gasket surface with the gasket removed. I will bench test them soon.
It is raining here now and suppose to rain until mid week so I will not reinstall the carbs until my new OEM fuel lines arrive.
Rob

[79XS11F]

Very Confused By No Start???

Well I now have the valve cover off again and confirmed that the cams are in the correct places (I'm checking EVERYTHING now) and valve clearances are good enough for the engine to start. Both cam dots are at the cam boss bearing arrows with the timing plate at "T" and the #1 Piston is at TDC. I even took off the timing plate to confirm that it was in deed on correctly. I have lots of nice bright blue sparks at the plugs. Carbs are no longer flooding so this engine should fire up. I am very close to switching out the coil wires to full reverse to see if ignition timing is somehow out 180 degrees but how could that even happen? Any input would be GREAT as I am temporarily STUMPED by this engine for the first time.
Rob

[TopCatGr58]

Hey Rob,

Can you recap for us?? You said something about having pulled this engine for putting in the 1179 engine, but now you have put this engine back into the bike??

Are these new plastic floats from MikesXS? Your compression values are not good for that one cylinder, but hate to ask, but did you check with throttle wide open, or carbs off and all plugs out??

I remember folks saying that you can use the MikesXS floats, but not sure IF the actual height setting is the same? You may need to do the right side up, clear plastic hose connected to bowl drain to measure actual fuel height once float bowl filled!?

Has this engine run since it was put back in the frame after it was stored??

When putting it back in, I guess the pickup coils could have been switched, but I can't remember how the plug is for the PU coils, whether it's one with 4 wires, or 2 separate 2 wire plugs? It would be a bit difficult to swap if it is a 4 way plug?

How are the intake boots? Did you verify that the jet for the enrichener in the float bowl is open and flowing? Just trying to brainstorm? Seems like I'm only able to muster a "sprinkle"?
T.C.

[79XS11F]

Hey TC here's a recap

I have have 1 bike and 2 engines (1979 frame, 1979 engine, 1978 engine) I hopped up the 1978 engine and used it last fall after running the 1979 engine for the summer. When I decided to restore the bike to factory condition I re-installed the 1979 engine. That's the one that came with the bike. It was stored on a stand and turned over from time to time. I have only one set of carbs so the carbs that are on this bike are the same ones that were used on the 1179 hop up engine except I returned the jetting to stock. The pickup coils are new last mid summer and are also the same ones and were used on both engines in the past so hook up is the same.
I was wondering if the plastic floats would be more buoyant and require a different height setting. They are from Mikes XS. The boxes say that they are for this model of carb. For myself I think the low compression numbers are related to excessive flooding so no oil on cylinder walls even with a few cc squirted in. Intake boots are also new with about 3 months use on them.
The last time i tried to start it the only noise it was making was sort of like a muted fire cracker followed by white smoke coming out of the air box. The only thing I did not check was if the pipes are free flowing. I am now wondering if perhaps some critters were in them and plugged them with a nest or food store or what ever. After all they did sit somewhere for several years.
SO I am in deed prepared to pull the head today if need be but that would be a shame if there is really only something else that's simple wrong.

[randy]

Rob,

Other than the coil wire being switched (unlikely unless you r/r the coils) The only way the ignition could be 180 degrees out is if you took the advance mechanism apart and put the reluctor back on 180 out. Don't ask me how I know, OK, I did it and my symptoms were similar, no fire but a puff through the carbs once in a while.