This is not my blaster, however my engine is sounding exactly the same,
Can anybody tell me what's wrong
Yamaha Blaster Engine Knock - YouTube
Can anybody tell me what's wrong
Yamaha Blaster Engine Knock - YouTube
Engine knock
- Thread starter Turbo
- Start date
Time to pull of the flywheel cover and investigate by revolving the flywheel back and forth.
Could be anything such as a screw coming loose and fouling, to a loose coil on the stator, even a clutch spring bolt working itself loose.
Let's hope it is not a piston circlip snagging a port or a reed screw embedded in the head
Could be anything such as a screw coming loose and fouling, to a loose coil on the stator, even a clutch spring bolt working itself loose.
Let's hope it is not a piston circlip snagging a port or a reed screw embedded in the head
I will check all the above thanks, could it be piston slap or crank, reason I ask is the last owner had been running it with the carb leaking air badly, I pulled the exhaust off and looked at piston with torch up the exhaust port, there is no scoring or obvious damage
No idea why someone would ride it like stink if it was making bad noise.
Anyhow anlong with above, check kicker idler gear, counter balance gear/brg, and oil pump if still present
Anyhow anlong with above, check kicker idler gear, counter balance gear/brg, and oil pump if still present
Right folks, got in from work and set about the motor,
Removed the fly wheel cover & spark plug, at tdc there was a rattle,
So pulled the head and nothing gone inside the barrel or head,
However my worst fears were confirmed, really sloppy piston in the barrel, scorch marks to the piston & barrel, it's been run way to hot due to lean mixture, the motor hasn't done much work as the barrel still has the honing marks,
The motor is 240 vito's bbk
Paul turner front pipe
FMf rear can
Pyramid reeds
Stock carb
Oil block off
These are the jets I pulled out of it
Main 250
Clip 4th
Pilot 25
To add to this lean mixture there was no
Rubber cap over the oil feed nipple to the carb
No wonder its knocking it tits off
The carb nipple is now blocked off
Main is 300
Clip is 4th
Pilot is 32.5
Going for a full rebuild now, I will post pics off the damage
Very soon
Removed the fly wheel cover & spark plug, at tdc there was a rattle,
So pulled the head and nothing gone inside the barrel or head,
However my worst fears were confirmed, really sloppy piston in the barrel, scorch marks to the piston & barrel, it's been run way to hot due to lean mixture, the motor hasn't done much work as the barrel still has the honing marks,
The motor is 240 vito's bbk
Paul turner front pipe
FMf rear can
Pyramid reeds
Stock carb
Oil block off
These are the jets I pulled out of it
Main 250
Clip 4th
Pilot 25
To add to this lean mixture there was no
Rubber cap over the oil feed nipple to the carb
No wonder its knocking it tits off
The carb nipple is now blocked off
Main is 300
Clip is 4th
Pilot is 32.5
Going for a full rebuild now, I will post pics off the damage
Very soon
A 250 main will do it every time with those mods. Good luck, hopefully there is no play in the rod bearing and your only looking at a top end.
Well I suspect the crank has also suffered from heat damage as there is a little oil coming from behind the flywheel, I think the crank has got hot and distorted the seals, so full rebuild = peace of mind, lol.
Should be ok with the clip on the second lowest position, but I would be doing a 1/2 TO 3/4 plug chop to confirm.
My needle clip resides on the second lowest position in summer and gets to the richest position in winter, as most would know I choose to run slightly rich for health of motor reasons, I no longer need to jet on the edge.
But get everything correct and you will enjoy many hours of fun on the little beast.
That piston shows symptoms of lack of correct warm up pinch. It looks like the scuffing is pretty well 4 cornered.
I notice the green base gasket, could that beggar have been leaky.
I notice the green base gasket, could that beggar have been leaky.
well it had been run on the 25 pilot so i suppose it would have warmed up way to quick, also the metal head gasket had gone a funny green colour in one place?
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