2T Sports Twin woes

[VeloGC]

Hi all, I haven't introduce myself formally yet, will do it soon. Apologies.

I have just bought myself what seemed to be a good example of the above as it's something I've fancied for a while as a light and nippy alternative to my Velo's. First impressions are not at all what I expected, smokes like a battleship ( on 50:1 fully synthetic ) and will hardly manage even the slightest upward incline without frantic downshifts to lower gears. This produces mrginally improved forward motion and traffic obscuring smoke !!!
Plugs seem clean enough and good condition and it starts readily. sit also leaks fuel when parked, with the fuel turned off - the garage is definately not an area to entertain a naked light.
Have removed carb , air filter, etc and currently have the element in soak to clean. Will check all settings before re-assembly but hope that this is the cause of the poor performance. I also went to replace the faulty fuel tap but was surprised to find that the tank connection is only 1/8" BSP. All my taps are 1/4" BSP, of course ! Is it possible to re-tap the tank boss to 1/4", or do I have to make a 1/8" to 1/$" adaptor ?
I get the feeling that I shall be picking your brains for a while, please bear with me. Regards, Geoff

[Guest]

2T Sports Twin Woes

Hi Geoff, welcome to the club. Your bike sounds like it is running very rich. It is possible that there is also a lot of old oily fuel in the crank cases. Firstly, I recommend draining the crank cases. There are two drain plugs on the bottom of the engine. Make sure you re-tighten them carefully and with new washers.

50:1 sounds a bit "thin" to me. Most guys seem to use semi-synthetic premix oil at about 40:1.
50:1 means that the engine is effectively running too rich on fuel if standard jets are used.

There is plenty of help available. I'm sure we can help to get it sorted.
Whereabouts are you?

Keith

[VeloGC]

Many thanks for your reply, Keith. I have already drained the crankcase when I first got the bike home last Wednesday. I used 50:1 as that wa recommended by the previous rider but I'll certainly change to your recommendation once I get everything cleaned out and re-assembled. I also have to make the fuel tap adapter so will hope to have it all back together in a couple of days. We shall see what it has to say for itself then !
I live near West Malling in Kent, the Maidstone area.
Thanks again for your welcome and suggestions.
Regards, Geoff

[John Pattinson]

2T Woes

Hi Geoff, 1/8 gas petrol taps are common and readily available...John P.

[John Wakefield]

Hi Geoff
I would recommend that you change to normal mineral two stroke oil, such as Comma Two Stroke http://www.autosessive.com/products/...JVkaArbI8P8HAQ
Its available from most DIY Car stores.
Villiers recommend 20:1 but it can be used up to 25:1 with no problem. I would not go above that as Keith says it upsets the air to fuel ratio on standard carb settings. Make sure you have the correct carb settings/jets your bike will probably have the S22 carb but later ones had the S25
The carb settings for the 2T as listed in Villiers Singles & Twins are as follows:
S22 carb
Main Jet (not listed but probably about 170) someone on here will know
Pilot Jet 35
Taper Needle 3 1/2
Groove 3

S25 carb
Main Jet 180
Pilot Jet 35
Taper Needle 3 1/2
Set out 1.94"
Throttle slide 3

Also check that the float needle is seating & the carb is not flooding.

If the bike has not been used much & only at low speeds you would expect quite a bit of smoke initially due to oil build up in the silencer. The Siamese system is particularity prone to this. Have you removed the baffle from silencer & cleaned it, the silencer may be choked with old carbon which would reflect on the poor performance. Also check ignition timing, 0.187" before top dead centre, is it firing on both cylinders?

[VeloGC]

Thank you all so much for trying to help a newby.
To clarify:
I have removed baffle and cleaned, cleaned out silencer body and pipes and re-sealed all joints on re-assembly.
I have drained the crank case, both plugs.
I have fitted new NGK B6HS (4510) plugs, gapped to 0.025". Both are sparking acceptably.
I have now raised the oil content of the petroil mix to 25:1, although currently still using fully synthetic oil.
I have also checked the carb. components against the spec'n and all seem correct except the throttle slide, which is 2.5 against the 3.5 spec'd and can find no markings on the pilot valve. I shall try to order new components tomorrow. The idle jet needle is set only 1/2 turn open, seems wrong so shall have to adjust when engine is running again. The fuel needle valve closes as per the spec'd 1/4".
The air cleaner element is still in soak but looks clogged to me. I'll blow it through tomorrow with the air line when it comes out of the washer.
I haven't checked the accuracy of the ignition settings yet but will do so.
Sorry to be so long winded but I thought I'd try to give as accurate picture as possible
Thanks again for your patience and assistance. I shall get it right, I promise!!!
Regards to all, Geoff

[46T Sprocket]

Hi Geoff,

How does the compression feel when you kick it over? Does it turn over easily or do you have you a good bit of resistance? Basically I'm asking if it feels like it has good compression?

Without knowing firstly that it is sound in both the cylinder and sound in the crankcase area. Are the seals in there doing their job? you are wasting your time changing the oil mix or fiddling with the timing. You need to be sure those parts of the motor are spot on first.

David.

[VeloGC]

Hi David, I bought the bike last Wednesday and was assured that the engine had been thoroughly checked and all that was done was to fit new piston rings. The compression feels good when turned over on the kick start. In fact it starts easily and sounds good. I shall get the components back to as near spec'n as I can and if still no joy will have to strip the motor and rectify any faults found.
Geoff

[John Wakefield]

S22 carb article

There is a Motor Cycle Mechanics copy featuring the S22 carb on eBay. might be worth buying it. http://www.ebay.co.uk/itm/Rare-VILLI...item4ade4b3c90

[VeloGC]

Thank you John. I have made a note

[Rob]

Sounds more to it than fiddling with the jetting? Provided there is no fault with the float causing flooding (even if only slight), how about a faulty crank seal (eg. not fitted correctly) allowing primary case oil to be drawn in? Having never owned a Villiers twin, I have no idea if that is possible but it can happen on Yamaha twins that I do own.

Regarding oil, start at a high ratio and work back until it stops seizing! Seriously, I run my trials bike on fully-synthetic Putoline MX9 at 40:1 and I think it would be OK at 50:1. It gets a good thrashing and hasn't blown up yet!

[John Wakefield]

2T problems

VeloGC, just a thought, you say you have recently bought the bike, would it be the Black 25DB that was recently for sale on eBay at Cambridge? If so I know this particular bike as it was previously owned by a local ex GRA member. I went with him to Battlesbridge a few years back & the bike behaved as you described, lots of smoke & lack of power, in fact it was only running on one cylinder. Despite checking the wiring etc it could not be made to run on both cylinders when we left Battlesbridge & he had to ride it home on one cylinder, top speed about 30mph & lower as soon as he hit a hill, having to change down a few gears. Strangely after refueling at Thaxted the bike suddenly picked up on the second pot & it rode home to Cambridge OK. He never did find out the cause, but did not ride the bike much after that, he then sold it to another local owner & he to the owner selling it on eBay. The bike came to one of our Cambridge meetings back in August & the owner had difficulty starting the bike then, in fact he had to have a push start. If it is this bike then I think it needs a full sort out both engine & ignition. I hopefully its not now your bike

[John Wakefield]

Sounds more to it than fiddling with the jetting? Provided there is no fault with the float causing flooding (even if only slight), how about a faulty crank seal (eg. not fitted correctly) allowing primary case oil to be drawn in? Having never owned a Villiers twin, I have no idea if that is possible but it can happen on Yamaha twins that I do own.

Regarding oil, start at a high ratio and work back until it stops seizing! Seriously, I run my trials bike on fully-synthetic Putoline MX9 at 40:1 and I think it would be OK at 50:1. It gets a good thrashing and hasn't blown up yet!

Rob as from what VeloGC says the bike starts easily then its unlikely to be seals. Could be a blocked air filter, but also see my previous post. The idea of starting with high oil ratio & increasing it if it seizes is not a good idea, best to adhere to manufacturers spec, particularly on a twin. The centre seal & bearing gets little cooling & it needs good lubrication.

[Stuart Baskill]

VeloGC, just a thought, you say you have recently bought the bike, would it be the Black 25DB that was recently for sale on eBay at Cambridge? If so I know this particular bike as it was previously owned by a local ex GRA member. I went with him to Battlesbridge a few years back & the bike behaved as you described, lots of smoke & lack of power, in fact it was only running on one cylinder. Despite checking the wiring etc it could not be made to run on both cylinders when we left Battlesbridge & he had to ride it home on one cylinder, top speed about 30mph & lower as soon as he hit a hill, having to change down a few gears. Strangely after refueling at Thaxted the bike suddenly picked up on the second pot & it rode home to Cambridge OK. He never did find out the cause, but did not ride the bike much after that, he then sold it to another local owner & he to the owner selling it on eBay. The bike came to one of our Cambridge meetings back in August & the owner had difficulty starting the bike then, in fact he had to have a push start. If it is this bike then I think it needs a full sort out both engine & ignition. I hopefully its not now your bike

I bought a 2T about 20 years ago and finally fitted it into a Greeves 25DB about 10 years ago.The engine was in new condition and hardly used.When I fired it up it was mainly running on one cylinder.Eventually I found the fault.One of the wires to a contact breaker was internally broken.It only showed up when I pulled it and it stretched like knicker elastic.Once I changed the wire it was ok.

[VeloGC]

Thanks again chaps. Yes, John, you are correct and I'm afraid I was fool enough to believe the lies that were told to me. Worse than that I paid a high price for what seemed to be a good machine and hired a van to drive up to Cambridge to collect it !
I now believe that there is, and has for a long time, something seriously wrong with the machine that I have bought in good faith.
I guess the phrase, " Caveat emptor" is aimed at trusting mugs like me.
Should definitely have stuck to Velo's, I understand those !!!!
However I have a problem and I need to sort it out.