GT250 will not start (PVL ignition)

[belopsky]

Hi all,
Just picked up a 1976 GT250 with ~2900miles.

I cannot get it to start. Checked compression, seems to be enough. Have spark. Plugs are getting wet.

It's got a PVL ignition, not sure if the timing is set correctly. Previous owner said he had a heck of a time getting it to run by kickstarting, but he could bump start it.

I tried drill starting, but it would not start.

I have not been able to find a manual for how to check timing/set timing..which cylinder do I base timing off of? I found some instructions for a PVL ignition and it says to base it off the left cylinder.

The crank rotation is counter clockwise, upon checking it seemed that the spark was firing on the WRONG side of the stator, PO maybe had it reverse..


I have almost everything to put the points ignition back on minus things like the nut/bolt to crank it on the crank, woodruff key, maybe some nuts..I'd prefer to stick with this PVL unless someone has a different ignition suggestion? As I was told, the PVL won't run the battery/charge it and lights don't work w/o battery, but I dont know..

[jabcb]

Do you have a dial indicator so you can check the timing based on piston location?

[belopsky]

Do you have a recommendation on one? The one I have doesn't reach the piston..

[jabcb]

I don't know what's available. Mine is older that your GT250.

[belopsky]

What do you use?

[tz375]

PVL ignitions usually fire up at somewhere around 500 rpm and sometimes they need to spin faster than that to light the fire.

I haven't used or tested a PVL but I see a lot of racers using starters because they can't run fast enough to fire up a bike with a PVL. Or maybe they are old...

It should start with an 18v drill as long as it turns at 800 rpm or more. We use 22,000 rpm 1/2HP router with speed control to test that type of system on a jig.

On my TZs with a Hitachi, Motoplat or FEMSA they will fire at around 400 rpm which is like a hard kick but they usually need more speed to get the fire going and if jetting isn't perfect it can be a long hard push.

A simple test is hook up a digital tachometer and push the bike with plugs out and grounded and see what engine speed it starts to spark. If speed is too low, no spark and no reading, so that makes it easy to see. Then repeat kicking it over and if you don't get a reading or a spark, it isn't turning fast enough to generate a spark.

If it's a street bike I'd suggest getting a DYNA S system and sell the PVL. Do you still have the charging circuit and alternator to swap it back to a normal street set up that makes fattest sparks at low speed - the opposite of a PVL self generating system.

[belopsky]

Hmm well I definitely have seen spark when kicking it by hand.

[jabcb]

You could use an inductive timing light to see if you get a spark with the plugs installed.

Newtronic is available for the GT250.

This is the type of dial indicator that I have. The eBay item appears to be missing the screw used to lock the indicator into a fixed location.
http://www.ebay.com/itm/VINTAGE-YAMAHA- ... 0610305208

[locobuilderbri]

Normal convention when timing engines is to time no 1 cylinder, that is usually the one on the "free" end of the engine.
ie Not the drive end.
On T250/GT250 thats the l/h one & the set of points that fire no1 cylinder is the front set. ie the l/h set when viewed from the l/h side of the bike.
Double check its actually that cylinder thats firing as its easy to be timing on the wrong cylinder!
On the t250 the HT lead for the no1-l/h cylinder had a silver band on it but that may be missing by now, But its the l/h
coil if the coils are mounted with the HT leads facing forwards (the parts book shows the coils mounted HT leads at the rear) if thats the case cross the HT leads.
Not conversant with PVL systems but bring no1-l/h cylinder to roughly TDC Top Dead Centre & which ever "trigger" is the closest is the one to time.
Regards Bri e

[belopsky]

Not sure what you mean by free side versus the drive side. Is it the side w the magneto or the side w the clutch? The side w the kick starter or the side with the brake pedal?

As far as inductive timing light: I have one but i can't use it until the bike idles?

[Suzukidave]

I looked to Google for info and there appears to be some https://www.google.com/#q=PVL+ignition+setup" onclick="window.open(this.href);return false;

[Coyote]

I have never heard of a PVI ignition and have no idea what PVI stands for. However from TZ's description, it doesn't sound like a very streetable system. You say you have most of the stuff to put the ignition back to stock. That sounds like the thing to do. Get back to ground zero so to speak. I'm sure if you leave it as is, you will run into situations where there is no enough room to bump start it and kicking appears to be pointless (no pun intended).
Start with the stock setup and get everything working right (regulator, voltage regulator charging) and ride it for a while. Later on you can fork out for a DynaS or other proven street system if that's your cup of tea. Suzuki produced hundreds of thousands of bikes with ignitions that work. So why mess with it?

[belopsky]

I totally agree with you. Not a fan of points is all. I'm all for a Dyna s system..I like simplicity..

[tz375]

Timing is done on the left side with a PVL and it's usually done statically, but you could use a timing light to see where it fires as a rough starting (no pun intended) guide.

PVL is a race system made in Europe. It's a self generating CDI ignition so no battery. UNLESS it's not a PVL at all but an MZb Powerdynamo which is OK for a street bike but just as much of a PIA to time because the rotor is not keyed to the crank.

Please post a picture of the bike and PVL.

[belopsky]

Definitely a PVL. #105 458 is the number on the coils themselves.

Here is what mine looks like. As it is in this photo, is how it was mounted on my motorcycle.


I take it I should get the LEFT cylinder to TDC and go a few MM BTDC. As I do not have a dial that currently works, not sure how I will adjust. I can find TDC with my piston stop, however (or close enough..)

If I understand correctly, I should get the LEFT piston to the correct mm BTDC, set the rotor so that the mark on it matches w the mark on the stator (as in my photo, the one on the top right right), tap it on with a rubber mallet to make sure it doesn't move, and make sure that this stator goes to the coil that goes to the plug on the left cylinder.

I've heard some mixed things, but given timing and compression and fuel..I shouldnt have issues kicking it over? If it is, indeed, an ignition that requires bump starting, this will not work for me as ultimately the bike is being built for my girlfriend..