How To Guide Engine wont start? TROUBLESHOOTING GUIDE

CrazyDan

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Jul 9, 2016
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1,576
Hi what would it mean when I undo my mag cover an fuel come out of were the magneto sits and also will a small imperfection in a piston stop a motor running I've got like a little graze tYpe thing on the edge of my post on an its,a tiny bit deep can rub my nail on it and deal it
Fuel leaking out from around the mag sounds like a blown out crank seal.
 


inspectorcritic

Active Member
Joined
Dec 13, 2015
Messages
782
Hi what would it mean when I undo my mag cover an fuel come out of were the magneto sits and also will a small imperfection in a piston stop a motor running I've got like a little graze tYpe thing on the edge of my post on an its,a tiny bit deep can rub my nail on it and deal it
Your side seal needs to be replaced sits beneath the magneto
 

Chrishammant

New Member
Joined
Mar 8, 2018
Messages
2
fuel in the magneto is likely a bad seal behind the magnet rotor. I had a seal come out with the rotor when changing the rotor. Thing is the seal was not leaking. I got a seal retainer off EBay $7.00.
Was a little worried about the rotor touching it, but so far so good.
Ok thanks mate an also my other motorised motor bogs down at top rev an starts to die them come back

That would mean it running to ritch right was gonna move my needle clip either up to very top an see how it went but don't wants to stuff or so I'd thought I'd asked if it would be wise to do so
 

danlandberg

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Apr 25, 2009
Messages
535
If you move the clip up it will lean the mixture. More air to fuel. I would go one notch at a time with test rides to get up to temp.
 

FurryOnTheInside

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Sep 23, 2013
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3,358
Ok thanks mate an also my other motorised motor bogs down at top rev an starts to die them come back

That would mean it running to ritch right was gonna move my needle clip either up to very top an see how it went but don't wants to stuff or so I'd thought I'd asked if it would be wise to do so
If you really think it's rich at high RPM then I would upgrade the air filter.
In fact, I would upgrade the air filter anyway, always, because the stock air filters are just awful.

The needle setting affects fuel flow at 0-3/4 throttle. The jet size affects fuel flow at 3/4-full throttle.

At high RPM the engine is trying to get all the fuel and air it can. If the air filter is at all restrictive then there is an undersupply of air (choke!) and perhaps the resulting vacuum is also drawing fuel directly rather than by purely Venturi action.
 

crassius

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Jul 23, 2012
Messages
4,575
if it is surging (slowing down, then going back up, and repeating) that usually is caused by vibration in carb foaming the fuel

several threads about that here
 
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