• Welcome to the Yamaha FZ6 Forums. Member registration disables ads and allows you to post and share. Register Here.

No start situation after new battery and fuse

brandonbrown

New Member
Joined
Aug 28, 2024
Messages
4
Reaction score
0
Points
1
Location
Houston
Visit site
After a new battery charged, and the 20a fuse for the main was swapped. No start continues to happen and you hear a pop each time in the 30a starter relay with perfect fuses on the battery terminal connections. Is this spark related considering the codes in the diagnostics.
 
I think I’m going to need a little back ground. What were the conditions that caused the main fuse to open originally? What codes are you getting? What happens when you place the ignition key to the “On” position? Were there any anomalies the last time the engine ran?

Also, if the engine can not turn over, it’s clearly not spark related.
 
All before the no start situation i had installed a manual cam chain tensioner and it had came undone as the engine rough as something was slapping.

I was a block away from home so i pushed in neutral with the hazards on and i thought it was only a dead battery but lead this situation.

I've looked at half of the valves through the throttle body and no damage to the valves
 

Attachments

  • no-start-with-new-battery-and-fuse-v0-neo48t0oyfde1.webp
    no-start-with-new-battery-and-fuse-v0-neo48t0oyfde1.webp
    143.2 KB · Views: 7
  • no-start-with-new-battery-and-fuse-v0-ypy2rs0oyfde1.webp
    no-start-with-new-battery-and-fuse-v0-ypy2rs0oyfde1.webp
    183.4 KB · Views: 8
I think I’m going to need a little back ground. What were the conditions that caused the main fuse to open originally? What codes are you getting? What happens when you place the ignition key to the “On” position? Were there any anomalies the last time the engine ran?

Also, if the engine can not turn over, it’s clearly not spark related.
Also timing did jump but i would expect atleast a crank
 
As the engine is an "interference engine" and you know the chain jumped,
it's very possible the valves kissed the pistons and locked up the engine.

Remove the spark plugs, the right side, round, plastic, crankshaft access screw cover.
Now try turning the engine over clockwise with a socket. If the engine locks up / or doesn't move
somethings VERY wrong in the combustion chamber (locked up engine).

Even with a new battery, a frozen engine, with power applied to the starter can pop the fuse.

Codes will be thrown as the cam is now out of time with the crankshaft..


.
 
As the engine is an "interference engine" and you know the chain jumped,
it's very possible the valves kissed the pistons and locked up the engine.

Remove the spark plugs, the right side, round, plastic, crankshaft access screw cover.
Now try turning the engine over clockwise with a socket. If the engine locks up / or doesn't move
somethings VERY wrong in the combustion chamber (locked up engine).

Even with a new battery, a frozen engine, with power applied to the starter can pop the fuse.

Codes will be thrown as the cam is now out of time with the crankshaft..


.
timing is corrected and engine rolls over 2 revolutions gonna put the rest the bike on later today
 
As the engine is an "interference engine" and you know the chain jumped,
it's very possible the valves kissed the pistons and locked up the engine.

.
I literally just learned the term "interference engine" several weeks ago. Sigh... my GY6-clone ("interference engine") scooter is no more. It shut down/left me sitting in November, and it took me until Christmas vacation to dig into the engine. Timing/cam chain broke, and I just decided given all the other issues this thing had (including some crumbling chinesium on certain parts of the frame) it wasn't worth trying to bring back from the dead. So I'm scooter-less, for now at least. RIP

PXL_20241226_224331940-COLLAGE.webp
 
Oops, that sucks...

My freebie Toro zero turn mower (18HP, B & S single cylinder) was blown
up due to the exhaust valve seat dropping and then the exhaust valve
(which snapped into two pieces). That then kissed the piston and head .
That was a major interference issue (4.5 years ago),

The cylinder wasn't touched so I bought a new head and piston (and rings from Amazon)
and re-assembled.


The carnage and repair:







All done:
 
Last edited:
How ‘bout this one…

30+ years ago I had a ‘87 MR2…one of the best sports cars ever made. I went all in when I bought it and checked every option; leather seats, power everything…the car was just perfect. In the early ‘90’s with about 150,000 miles on the car the timing belt broke (it was changed around 90k). I had it towed to a “friends” garage for repair and he tells me “sorry dude, interfere engine, not worth repairing”. I loved the car but it wasn’t worth the investment of a new engine. Friend gives me $300 for the car.

Fast forward 15 years and I’m researching MR2’s because I really missed my favorite car and I’m thinking of getting another. I discover that the MR2 DIDNT have an interface engine. My “friend” stole my car with a BS story. He bought for $300, replaced the belt, and probably sold it for $3,000.

Still hurts.
 
Friend is a loose term. He was a person on the periphery of a group of friends who had all either built or were currently building an airplane. He was a pilot, and he did hang out with the group at our hangar - and I'm sure he took a trip or two with us - but in the end I guess he felt that building an airplane was not in the cards for him and he eventually disappeared. Unfortunately he also disappeared with my much-loved MR2.

gnyce - pull the head off that thing and take a look at the head and piston. Maybe it can be saved for cheap. A head rebuild is a fun weekend project (although 50% of the labor is just removing the gasket :) )
 
Last edited:
Nope - it's already gone. As I said, it wasn't just this - there were parts of the frame that were pretty dicey - for example, the rear-swingarm (probably named differently in scooter-world) had a sketchy connection with some crumbling metal and bolts, the clutch mechanism had pieces that broke/were floating loose, same with the CVT variator pulley (metal guides). And parts availability? I could not even find a manual for this model. No, this is probably for the best - if I continue with a scooter, I'll get a better-supported model/manufacturer (honda, yamaha, maybe even vespa/piaggio)
 
Back
Top