How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jeff Policky Your Own Question
Jeff Policky
Jeff Policky, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 2425
Experience:  Yamaha Gold, Suzuki Gold, Honda Bronze, Polaris Bronze, BRP
17258690
Type Your Motorcycle Question Here...
Jeff Policky is online now
A new question is answered every 9 seconds

I have a '98 cv Virago which has been reassembled with good

Customer Question

I have a '98 cv Virago which has been reassembled with good second hand pistons/cylinders. Currently sparks excellent and turns over briskly BUT she just won't fire. Oil is new. Have retired/adjusted rappers/valves/timing 5 times but obviously seriously 'out' somewhere- latest theory I have is that the sparks may be delivered in reverse, to the wrong cylinder each 'firing'. Has backfired/ spat when juice introduced
JA: Where exactly do you think the noise is coming from? And how long has this been going on?
Customer: what noise?
JA: Are you fixing your 98 yourself? What have you tried so far?
Customer: Just replaced both cylinders with associated.pistons-supposed to be 'effective' , on
JA: Anything else you want the mechanic to know before I connect you?
Customer: have tried to send more info but get interrupted!
Submitted: 13 days ago.
Category: Motorcycle
Expert:  Steve replied 12 days ago.

what is the compression on each cylinder?

tell me everything you can.

Steve

Customer: replied 12 days ago.
front was about 80 + & rear about 110+. - I know this is low but it's cold. Repeatedly reset tappers/valves- seem perfect - injected juice through intakes (no filter and vac lines plugged) Turns rapidly, strong battery, no apparent "suck/blow". .and spat not fired . Latest theory,reversed ignition lines at coils & not firing in correct order (?). cylinders/piston units different US sources. eBay. Think I created a lemon!
Customer: replied 12 days ago.
I forgot. - one of imported sets had no 'ring of carbon' at top inside the barrel-it had been honed lightly. I checked the rings prior to assembly and both pistons seemed within spec...
Heads have been separately refurbed & are excellent - no suck , no blow ?! When last cranked she was wheezing through the open blow by tubes and at one of the rubber intake connections
Expert:  Steve replied 12 days ago.

your compression is too low.

you are going to have issues until you correct it.

your valve timing sounds off. (no suck, no blow?)

Steve