Topic: Belfast-2-Belfast-By-Bike: Part 3

[scottly]

It looks like you have a carburetor problem: too much fuel for those 2 cylinders.

[The Lone Builder]

It looks like you have a carburetor problem: too much fuel for those 2 cylinders.

I think you may be right! But until today, only No4 was affected - look at the pic showing the old plugs. The float was sticking on this carb resulting in overflow if I left the tap on when stationary. I was managing that by making sure to turn off the fuel just before stopping.

Since 2&3 are supplied by different spigots, that suggests the problem is with the individual carbs. Does that mean the float heights need to be adjusted?

Electrics check out except for the resistance on the 5Ω Dyna coils which is only 2Ω, on both; but this would affect all 4 cylinders, not just 2&3.

So now I'm going to check flow from the fuel tank, and if the two spigots are uneven, I'll drain the tank and check out the tap.

Then I guess its down to the carbs.

[newday777]

If I remember correctly didn't you put on an aftermarket petcock when you replaced it in the states(Pennsylvania??)
Drop the carb bowls and measure the fuel level in the bowls from the top to check if you have a float or 2 out of speck

[RAFster122s]

Did you trim the ends of the plug wires when you changed the plug caps?

[HondaMan]

It never stops! Or rather it keeps stopping!

I've had an intermittent misfiring issue for the last 3 days. 
Started on Sunday and then cleared. No 4 plug was black and wet, so I changed this.
Monday was great, ran sweetly.
Tuesday a rest day
Wednesday it started out OK, but then the misfire returned.  Same story with the plugs - 1-3 looked OK but. 4 was sooted. I changed all 4 plugs this time, and the bike died completely. I noticed the tank was almost empty - after only 130 Kms! – and switched to reserve. It ran OK around the carpark, but as soon as I loaded up and set off, the misfire returned.
This morning, Thursday, I took out the plugs: 3 & 4 were black while 1 & 2 were clean. The second pic shows the old plugs with the new ones.

Anyone have any thoughts?

I'm going to check coils, plug caps and plugs now, but it is unlikely that both coils are failing. Failing plug caps, again? Two HT leads not  performing well?

Sean: this strikes me as possibly being leaky carb hoses, especially since the carbs were just removed and reinstalled. Check closely those band clamps where they tighten on the carb's side(s) to the head: when re-used a lot the "hole" side of the clamps (where the screw heads are) often pull in toward the nut's side, like a funeel, thus making it impossible to fully vacuum seal the hose. The result of that is always black sparkplugs at the offending cylinder because the airflow is too slow thru that carb in the firing order, the crankshaft being dragged along by the other ones that are OK. As air slows down thru the carb throat for a given slide opening, it runs richer.

This has always been my "warning sign" that the hoses were getting too hard on the bike I rebuild.

[scottly]

It looks like you have a carburetor problem: too much fuel for those 2 cylinders.

I think you may be right! But until today, only No4 was affected - look at the pic showing the old plugs.

The old #3 plug has a glazed grey appearance on the inner porcelain, and it's hard to tell from the pic, but it looks like #1&2 may have some black carbon on the inner porcelain. I would guess that all four cylinders are running too rich, with #4 being the worst. I would check the float levels with the clear tube method. In a pinch, you can rig a tool using vinyl tubing and a cigarette lighter.   Also, sometimes you can salvage a fouled plug by burning the black off the porcelain with a propane torch, instead of buying new every time until you get things sorted.   

[The Lone Builder]

So!

Flow from the tank was OK, but, just to be sure, I took the petcock apart and all was well.

I drained all four bowl into glass jars and, using No 1 as reference, No 2 was OK, No 3 was a little high (too much fuel) and No 4 was overflowing. I checked the operation the fuel needle valve on No 4 and it wasn't seating properly, so I changed this with a new spare. This solved that problem. Photo shows the valve with some apparent roughness on it.

The bike ran well on start up so I took it for a ride and all went well!  Plugs 1 & 4 were clean after the ride.

So now I'm heading off early tomorrow morning to try to make up for lost time; I have a hotel reservation for tomorrow and a ferry booked for early Sat morning.

[newday777]

The download doesn't open, but, I saw the picture of the float valve on the blog, yes that rough spot will do it. Good you had another on hand. Is the new from Honda?

[MauiK3]

It sure does not take much to mess up a float needle!

[PeWe]

I hope you can enjoy your rides without any issues and worries about the bike.
Where to refill the tank, your stomach and where to sleep plus sightseeings including making new friends plus follow your plan are better thoughts

[grcamna2]

So!

Flow from the tank was OK, but, just to be sure, I took the petcock apart and all was well.

I drained all four bowl into glass jars and, using No 1 as reference, No 2 was OK, No 3 was a little high (too much fuel) and No 4 was overflowing. I checked the operation the fuel needle valve on No 4 and it wasn't seating properly, so I changed this with a new spare. This solved that problem. Photo shows the valve with some apparent roughness on it.

The bike ran well on start up so I took it for a ride and all went well!  Plugs 1 & 4 were clean after the ride.

So now I'm heading off early tomorrow morning to try to make up for lost time; I have a hotel reservation for tomorrow and a ferry booked for early Sat morning.

Which island are you on now ?

[BenelliSEI]

So!

Flow from the tank was OK, but, just to be sure, I took the petcock apart and all was well.

I drained all four bowl into glass jars and, using No 1 as reference, No 2 was OK, No 3 was a little high (too much fuel) and No 4 was overflowing. I checked the operation the fuel needle valve on No 4 and it wasn't seating properly, so I changed this with a new spare. This solved that problem. Photo shows the valve with some apparent roughness on it.

The bike ran well on start up so I took it for a ride and all went well!  Plugs 1 & 4 were clean after the ride.

So now I'm heading off early tomorrow morning to try to make up for lost time; I have a hotel reservation for tomorrow and a ferry booked for early Sat morning.

Which island are you on now ?

Whale Watching, north end of the South Island, just north of Christchurch……

[grcamna2]

So!

Flow from the tank was OK, but, just to be sure, I took the petcock apart and all was well.

I drained all four bowl into glass jars and, using No 1 as reference, No 2 was OK, No 3 was a little high (too much fuel) and No 4 was overflowing. I checked the operation the fuel needle valve on No 4 and it wasn't seating properly, so I changed this with a new spare. This solved that problem. Photo shows the valve with some apparent roughness on it.

The bike ran well on start up so I took it for a ride and all went well!  Plugs 1 & 4 were clean after the ride.

So now I'm heading off early tomorrow morning to try to make up for lost time; I have a hotel reservation for tomorrow and a ferry booked for early Sat morning.

Which island are you on now ?

Whale Watching, north end of the South Island, just north of Christchurch……

Nice 

[Little_Phil]

Kaikoura by any chance? When I was there there were two male sperm whales (I think) that have made their home in the deep ocean quite close in to the shore and never left. The local Maoris had built a good living out of them