Dan’s 3XV1

[AndyYam]

Worried about the like dark visible lines on the cylinder wall. Clean them off using a scotchbrite pad green colour. Match the cross hatching

Thanks Rick, however that doesn't help me understand why they are there in the first place. Cleaning them off is fine but they're only going to reappear as soon as the engine  is started. Anyway I've since had a chat to a few guys in the know and problem solved.

What was the upshot of this? Do you mean the advice to warm up for longer before high rpm or did you find out other info?

[SeaR1ck]

It's mostly just a visual thing the dark marks. Usually see them caused after someone gets thier cylinders replated and they didn't clean the honing debris out good enough after they got thier cylinders back from the platers.

Or it can be caused from improper warming up the bike and revving it up into to high of rpms. Before the pistons have had a chance to heat expand. This is more important when running forged pistons vs cast. Forged pistons take longer to warm up.

[Dan_152]

Long time no speak! Hope everyone is well.

Do any of the more experienced on here know if there is a way to test and verify a bad water pump seal? The last couple of times I've checked the coolant on the 3XV I'm noticing a minuscule amount of what appears to be oil, sitting on top of the coolant in the radiator. It's not milky or anything, sorta just looks like froff, and the rubber seal on the cap has an oily feel to it.

When I rebuilt the engine I changed this seal so it's less than 1000kms old.

Is there a way to test the water pump seal from the gearbox side? I would expect if the seal was damaged that coolant would leak into the gearbox and not the other way round. Maybe some very light air pressure through the gearbox vent whilst watching the  top of the radiator?

Oh and just to clarify the trans oil isn't contaminated with coolant.

[mellorp]

IF you have a leak then the coolant level will drop over time.
Take the cap off and fill it to the brim. Come back 24 hours later, if it's dropped you have a leak.
Next with the cap off, start the engine. If you touch the throttle the level should rise and fall gently. If you rev it and it starts spurting out like an erupting volcano the you have a leak of some description.

[yanw]

I found that when I had oil in the gearbox the sight glass would show "oil" when left to stand (it floats) but was milky running and just after stopping.

[Dan_152]

Hello all,

Does anyone know what the purpose of the small white plastic tube that sits in the pilot jet passage is for? I've attached a picture of it

I'm pretty sure I don't remember seeing this when I last had the front cyl carb apart and I wonder if it's causing the front cylinder to run rich on the pilot

[Warwick]

Hello all,

Does anyone know what the purpose of the small white plastic tube that sits in the pilot jet passage is for? I've attached a picture of it

I'm pretty sure I don't remember seeing this when I last had the front cyl carb apart and I wonder if it's causing the front cylinder to run rich on the pilot

Dippers for the pilot fuel flow. Should be fitted in both carbs. 

[Dan_152]

Thanks Warwick. I refitted the plastic tube to the carb but still running slightly rich,  not exactly sure what these do for the fueling..

Bike runs nice and crisp with a fresh plug but if you let it idle for any amount of time it quickly loads up and needs "clearing out" down the next stretch of straight road. After this the throttle feels much more responsive but soon loads up again waiting at the next red light.

I will try backing out the air screw before changing jets, and if no luck maybe go down one on the pilot and perhaps drop the needle a notch. See how it behaves then. Bearing in mind it's quite warm in WA this time of year  so maybe this explains the richer running condition. We'll see.

[Warwick]

Thanks Warwick. I refitted the plastic tube to the carb but still running slightly rich,  not exactly sure what these do for the fueling..

Bike runs nice and crisp with a fresh plug but if you let it idle for any amount of ti
me it quickly loads up and needs "clearing out" down the next stretch of straight road. After this the throttle feels much more responsive but soon loads up again waiting at the next red light.

I will try backing out the air screw before changing jets, and if no luck maybe go down one on the pilot and perhaps drop the needle a notch. See how it behaves then. Bearing in mind it's quite warm in WA this time of year  so maybe this explains the richer running condition. We'll see.

Sounds like a plan. Be worth checking all is working well in the choke circuit and mechanism too of course. 👍

[Dan_152]

Thanks Warwick.

Any chance you could point me in the direction of the apparent 3XV carb setup guide you wrote? I've seen a few members mention it before and feel that a stepped procedure will be useful to me.

[Warwick]

Thanks Warwick.

Any chance you could point me in the direction of the apparent 3XV carb setup guide you wrote? I've seen a few members mention it before and feel that a stepped procedure will be useful to me.

It was probably just a general guide to how I've always done it in response to a question I expect, Dan. Search might turn it up? Always worth searching through the older forum links too?

It's important to take extra care with the cable set up to the lower carb especially by backing off all the adjusters so you are sure the slide isn't hanging up at all - though that generally causes starting and tickover problems. If it's definitely just  running rich it's more likely a simple pilot or choke issue. Keep at it; you'll find it.