Moderator: chasthor

Carb Queries

chasthor
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chasthor
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Joined: 7:40 PM - Jun 29, 2005

2:55 PM - May 16, 2008 #1

Ok, I want to put my hand up and admit that I know little of the workings of the carb! I no less than that when it comes to phrases such as " four stroking" and the like.
Threads have come and gone about "my engines doing this and what is the solution?" and so the solutions are lost too!
Our search facility doesn't! and trying to remember who started a relevant thread is a non starter, except for very recent threads, or for those who have instant recall.

So, in short, would someone, or a collective, write the definitive guide to carb troubleshooting, and we'll ask Mr Web very nicely, to pin it for future reference. There can't be that many areas, can there?

The reason for this, is that mines doing some annoying stuff and i really don't know the answers!

Anyone think likewise?
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chasthor
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chasthor
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3:52 PM - May 16, 2008 #2

Ok, I might have jumped the gun here. Just found this link from another thread:

http://www.iwt.com.au/mikunicarb.htm

Can we pin this link Andy?


I still don't understand 4 stroking though
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max
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max
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4:11 PM - May 16, 2008 #3

Four stroking is when youv'e got something dodgy with the mixture and the engine is only firing once every two full revolutions of the crankshaft. Whereas a stwo stroke should be firing every full revolution. This can be caused by too much oil in the mix or a dodgy ignition system too. Also can be caused by too richer mixture.
Its finished Bike Pics
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chasthor
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chasthor
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5:09 AM - May 17, 2008 #4

Ok, thanks for that Max. It's not doing that, but if it starts, I'll now know what it is
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Fs1eweb
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Fs1eweb
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5:23 AM - May 17, 2008 #5

Sorry the Search does not work! But I can pin this topic! Pinned!
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GARRY KENNY
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GARRY KENNY
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3:18 AM - May 18, 2008 #6

TOSSER
THE BANNED ONE , BEGGED BACK ,,AND FORGIVEN 90 FOR 09 ? WELL 87.5 AND STILL GOING FOR IT
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chasthor
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chasthor
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8:07 AM - May 18, 2008 #7

GARRY KENNY wrote: TOSSER
I know Gary, I just can't help myself :lol:





Whats your excuse
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mech73
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4:50 PM - May 26, 2008 #8

chasthor wrote: Ok, I might have jumped the gun here. Just found this link from another thread:

http://www.iwt.com.au/mikunicarb.htm

Can we pin this link Andy?


I still don't understand 4 stroking though
That article is good at explaining how the carb works and the overlap between the various jets. Not sure I agree with its advice on checking mixture. I've always found it difficult to use the plug colour as a guide. The top of the piston is a better. If it's dark and wet it's rich. Dry but dark brown to black is ok. Grey is too lean and white is probably too late. If you have just ridden at small throttle setting through a mile of housing estate, you will get a false indication though. To get a true reading you have to cut the engine after holding it flat out for a couple of miles. Then expalin to the officer why it's important that you remove the cylinder head on the hard shoulder.

If you want to experience four stroking on a two stroke the easiest way is to deliberatly over-richen the mixtureby turning the choke on with a warm engine. The spluttering just before it fouls the plug up is four (or possibly eight) stroking. Most of the Yamahas I've owned used to four stroke at high revs and wouldn't quite redline, when they were first opened up after running round town. After about half a mile and loads of blue smoke they would clear and run fine.

Cheers

Mark C
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ChazEverest
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5:12 PM - Oct 07, 2009 #9

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GARRY KENNY
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GARRY KENNY
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9:55 PM - Oct 07, 2009 #10

sounds like my 100cc usa fizz
THE BANNED ONE , BEGGED BACK ,,AND FORGIVEN 90 FOR 09 ? WELL 87.5 AND STILL GOING FOR IT
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