PVL timing

[riding4fun]

Here's the deal, I changed cranks from a 42 to 45 with a large taper. I had a pvl with the small taper crank. I have since found a large taper rotor and installed the pvl back on.

Now I set the timing at 1.7mm before TDC and it seems to some sort of a backfire when I kick it (just a ping in the pipe). Can't get it started and every once in a while it also sounds like a back fire with just air.

Would changing to a different rotor cause differences in timing. This is a brand new motor never fired.

Any help is appreciated.

Darrell

[JAG Motosports]

The longer rod will change the timing. The manual will have the TDC figure.

[mini racer #39]

1.2 to 1.5 before top dead center

[riding4fun]

Thanks, I will try that.

[bulldogfallon]

Are you using the right timing marker?

Different brands/types time from different marks

Call Matt 561.719.2218 he will walk you through it.

[LT80]

I set mine up at 1mm.

[hotquads1]

This is an analogue pvl , right ?

[riding4fun]

Originally posted by hotquads1
This is an analogue pvl , right ?

It's the malossi unit. Site says this one is digital.

[riding4fun]

Originally posted by bulldogfallon
Are you using the right timing marker?

Different brands/types time from different marks

Call Matt 561.719.2218 he will walk you through it.

Ya, I lined up the marks. There is only one on each.

[riding4fun]

OK, I have tried between 1.0 and 2.25 and it still won't start.

What's the chances that by mix matching the rotor from a different PVL unit it's just not matching up right.

[raidernut]

is the rotor you are using have a keyway?

[riding4fun]

Originally posted by raidernut
is the rotor you are using have a keyway?

I believe it does but so did my small taper rotor.

[camsdad]

you sure youre not timing it atdc,easy to do...

[riding4fun]

Originally posted by camsdad
you sure youre not timing it atdc,easy to do...

Ya, I have pulled it out and set it again. All I can think of is this (PVL) rotor is not working with my Malossi set up.

This is going to ruin the start of the season.

[jasonsdad]

If you still have your old small taper rotor take a look at it and make sure it is keyed in the same place as the new one. I have ran into this problem more than once. If they are not mark the big taper one to match the old one and you will have a better starting point.


EDIT
And by keyed I don't just mean the key on the shaft (if it has one) I mean the mark on the rotor compared to the magnet on both rotors

[riding4fun]

Originally posted by raidernut
is the rotor you are using have a keyway?

I just pulled off the large taper rotor and it does not have a keyway.

I also compared the markings they look to be in the same place on each.

[jasonsdad]

OK just a stupid question. You are getting fire right.

[hotquads1]

I know you have the timing marks ligned up , but it sounds like you may 180degrees out . The timing is not just off by a couple of degrees or it would run fine, either way maybe a little lazy. Try this , add an additional mark at 180 degrees (directly across from the current mark, and use this new mark as your timing mark and see what the results are . should take about 10 minutes. Also confirm that there is no damaged or pinched wire that could be getting a ground signal, and that there is sufficient air gap between the pick-up and rotor, just one metal shaving here can reek havoc.

[zach R 7x]

riding4fun,
sent you a pm.

[riding4fun]

Originally posted by jasonsdad
OK just a stupid question. You are getting fire right.

Yes

[riding4fun]

Originally posted by hotquads1
I know you have the timing marks ligned up , but it sounds like you may 180degrees out . The timing is not just off by a couple of degrees or it would run fine, either way maybe a little lazy. Try this , add an additional mark at 180 degrees (directly across from the current mark, and use this new mark as your timing mark and see what the results are . should take about 10 minutes. Also confirm that there is no damaged or pinched wire that could be getting a ground signal, and that there is sufficient air gap between the pick-up and rotor, just one metal shaving here can reek havoc.

I'll try turning it 180.

[riding4fun]

I went out and messed with it again. Tried it at 180 degrees the other way. That was way too much as it kicked back violently. After trying several different positions it did fire for a few seconds, but not again.

So for the heck of it I put the pvl back on the 70 motor just to make sure it wasnt the pvl causing the problems. It fired right up. So im at a loss. Guess I need to sell this unit and get something that works together.

Thanks for everybodys help.

[hotquads1]

has this new engine ever been cranked ? could it be an air leak causing a lean condition ? Might want to pressure test just to confirm engine is sealed .

[hotquads1]

Hi Darrell , did you get the pvl straight ?

[riding4fun]

No Marc. I tried it all over the place. Sold that PVL, buying another that should work together better.

Thank you for your help as always.