Rebuild Thread (Probably)

[Ciaraneng]

UPDATE: Since I did the rebuild I have been mostly noodling around back roads near home. I suspected that the misfiring was down to water in the fuel and pretty much confirmed it when I found some clear heavy fluid mixed in with the petrol when I emptied the filter.

I decided to go for a decent fast run to try to flush it through the system. It ran like a dream. No problem doing 60mph on the flat with plenty more in reserve. I’m hoping it’s just some condensation after the tank being left empty all winter during the rebuild. My driveway is really steep so any water in the tank would tend to end up in the lines and the carburetor. I guess if I have a hole in the tank I’ll find out soon enough.


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[937carrera]

Clean the plugs up and put them back.

I would tend to agree that the mixture looks weak, except on number 3. Misfire on WOT could indicate a lack of fuel in those conditions. Could there be an air leak into those 3 cylinders ??

[Ciaraneng]

Clean the plugs up and put them back.

I would tend to agree that the mixture looks weak, except on number 3. Misfire on WOT could indicate a lack of fuel in those conditions. Could there be an air leak into those 3 cylinders ??

Cheers for the reply Carrera. I took my time when fitting the rebuilt carb and the cleaned up DG manifold. I made sure the gasket was well centered and that the bolts were nicely torqued so I'm hoping I don't have air leaks now. I might get a local garage to do tune-up using a CO2 kit. I'm really focusing on the water in fuel as being the cause of the misfiring. I'm thinking I'll set up a temporary 'water trap' in the petrol line at the weekend and run it on a steep incline to see if I can maximise the water coming out. I wonder if getting some water in via the fuel line could whiten the plugs either through running lean or from steam cleaning? What does WOT stand for?

[tobydog]

How old are the spark plugs?

[937carrera]

WOT = Wide Open Throttle

If you have a water in tank problem, get yourself some suitable containers, drain the tank fully and put fresh in. Problem eliminated and less oportunity for a rusty internal tank.

If left for a few days the water phase will be visible and separate from the fuel, so you will be able to recycle the majority of the fuel. Water is heavier than petrol

[Ciaraneng]

How old are the spark plugs?

They have less than 2000 miles on them I'd say.

[Ciaraneng]

WOT = Wide Open Throttle

If you have a water in tank problem, get yourself some suitable containers, drain the tank fully and put fresh in. Problem eliminated and less oportunity for a rusty internal tank.

If left for a few days the water phase will be visible and separate from the fuel, so you will be able to recycle the majority of the fuel. Water is heavier than petrol

Thanks carrera. Unfortunately I have a full tank now but I'll try that when I get it a bit lower. I'll try my water trap arrangement in the meantime. I have a design in mind.

[ajsimmo]

Try this.

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[Oldiebut goodie]

You will never get all the water out of Eire with that little bottle.

[Ciaraneng]

Hi folks. Well I got to the bottom of my misfiring issue. I found water in the fuel filter, the feed line and in the carburetor. I took out my carburetor to replace the choke pull-down unit and emptied it into a glass jar. See below for a photo. It seemed to only draw in the water when the throttle was fully open.

Anyway, I set up a basic water trap, pumped a couple of liters through using a grenade hand pump, dried the carburetor and fitted a new fuel filter. I just had a long weekend without a misfire and more power than I know what to do with!

The 3E2 has made a massive difference to the power. Thanks carrera and Paul for the advice to replace. Thanks to them and to all the contributors to this thread. It enabled a novice who had never done more than a basic service to do an engine rebuild.

I couldn’t have done it without you guys.

[bigbadbob76]

From past experience with water getting in my trike tank, the fuel sits on top of the fuel in the carb float bowl so gets drawn off first at low throttle openings.
At wide open throttle the engine is sucking harder and draws some water too.
I had a few occasions when I was sat at the roadside with the top off the carb, mopping out the water.

[Oldiebut goodie]

From past experience with water getting in my trike tank, the fuel sits on top of the fuel in the carb float bowl so gets drawn off first at low throttle openings.

Silly fuel!

[Ciaraneng]

From past experience with water getting in my trike tank, the fuel sits on top of the fuel in the carb float bowl so gets drawn off first at low throttle openings.
At wide open throttle the engine is sucking harder and draws some water too.

That's exactly what I was seeing BBB. Uphill at WOT was the worst for some reason. Maybe the incline made it worse.

[Ciaraneng]

I'm up to 500 miles now and just about to do the first oil change on my rebuilt DG.

What is the general opinion on using an engine flush additive on a newly rebuilt WBX? Is it necessary/worthwhile? Is there any down-side or watch-out?

Thanks, Ciaran

[itchyfeet]

I'm up to 500 miles now and just about to do the first oil change on my rebuilt DG.

What is the general opinion on using an engine flush additive on a newly rebuilt WBX? Is it necessary/worthwhile? Is there any down-side or watch-out?

Thanks, Ciaran

No don't IMO, no point and it may just damage seals.

Just give it an oil and filer change

Marco Mansi always advised ZDDP additive like camshield, it's expensive so 1/2 bottle is probably enough to top up the oil levels ( I tried hard to work out PPM levels but it's a minefield), it's been reduced in all oils to protect cats but we don't have them

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