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  • Alex changed the title to Massimo 500 wont start, Got Fuel, Dry spark plug
Posted
23 minutes ago, Lance Darbonne said:

Massimo 500 wont start.  Pulled the injector and when i turn the key it sprays a lot of fuel, but the spark plug is dry.  What would be my next step?  Valve adjustment?

You need three things to run an ICE: fuel (a proper air/fuel mix), compression and a spark at the correct moment. One of those is missing. 

Easiest thing to check next (if you have not yet) is for a spark. OHC valvetrains rarely wear themselves tighter (s o tight as to not close and not allow some compression)--not what I'd check next...

 

Posted

As I alluded to above, with an engine that was  running reasonably well before a starting problem valve adjustment would likely be the last thing I'd check--just yank the plug and test the compression. If an intake or exhaust  valve is not closing tightly the cranking compression will be rather low (likely <100 psi)...

Posted

Thanks Guys, the thing that was puzzling me was that the injector was sending fuel, but the spark plug remained dry, which is why i asked about valve timing, but it does make sense what cliffyk said.

When i pulled the injector, it didn't really send a fine mist, but wasn't a solid stream, but it is sending fuel.   What would cause that fuel not to go into the cylinder?

Posted
7 minutes ago, Lance Darbonne said:

Thanks Guys, the thing that was puzzling me was that the injector was sending fuel, but the spark plug remained dry, which is why i asked about valve timing, but it does make sense what cliffyk said.

When i pulled the injector, it didn't really send a fine mist, but wasn't a solid stream, but it is sending fuel.   What would cause that fuel not to go into the cylinder?

That is perplexing--Check the spark and compression. Is there a smell of gas in the cylinder? I have seen "no-start" EFI systems where the fuel just ran down the cylinder wall and into the crankcase--does the oil smell of gas?

  • Like 1
  • 1 month later...
Posted

Guys, I want to thank you for all of your help, as well as let you know what the problem was.  I went on an out of state trip after my last post, so hadn't had time to get back on this unit until lately.  During my initial troubleshooting, i was on the drivers side working on the unit and my granpa was on the other side.  When i went back to verify the injector had a good spray pattern, i was not getting any fuel out.  I wiggled something and it started spraying again.  I leaned over to look at the fuel pump and noticed fresh oil.  Traced it to the oil filter which was barely hanging on.   

So, the whole problem was an oil filter with the wrong thread type was installed.  It screwed on, but over time, and with vibration, came loose and fouled the threads on the filter.  After it started spewing oil, i guess the low oil sensor was engaging causing the bike to dye intermittantly, until the oil was never able to reach the sensor.  I ordered a new filter, installed, and topped off the oil, and now she is running great.

The only thing i wonder is why i was getting fuel and fire with pretty much no oil?   I would figure that the sensor would kill the fuel or the fire???

  • 2 months later...
Posted

I have a 2017 missimo 500 I am replacing the fuel pump the replacement pump has the two lines to the Lead out ports which is ok but on the pump housing it has a open hose nipple where does it go

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