Too rich, flooding and starting w/o choke.

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BaNZ
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Too rich, flooding and starting w/o choke.

Post by BaNZ » 07 May 2023, 14:57

So, guys, before I tear my baby apart, I wanna ask you, should I do it?

My CRM Mk3 has Keihin PWK33 carb (145/40 jets), Boyesen reeds cage, other parts of powerplant is stock. Standart bore. I assembled it with new cylinder and new piston.

It run fine, had a right color on spark plug, always started with choke from the first kick, then started first kick when hot easily.

Couple of years ago I fueled up bike, ride it, then put it in storage for off season. In summer I tried to start it with no luck. Well, as it occurred I filled it with very bad fuel last time. I found some green poo inside dry carburetor, cleaned it out, changed fuel in fuel tank, and tried to start.

And it started. But I was forced to turn in idle screw way too much to make it start. Previously with this much screw in, it would have very high idle RPMs, but now it run just normal. And bike started without choke. When I removed airfilter, it did nothing. Air screw turning makes no effect on engine RPMs. Actually, I turn out air screw completely, and nothing changed.

Compression at 7 bar (never measured it before), spark plug all black and wet, sparking is good, starts good from first kick without choke, and there is almost no torque increase in 1/4 - full throttle opening when riding.

Any help appreciated as I really have no clue whats wrong. CRM was very simple and reliable bike to ride and work on.

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knackeredMk1
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Re: Too rich, flooding and starting w/o choke.

Post by knackeredMk1 » 08 May 2023, 17:28

Clean out the carb.

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BaNZ
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Re: Too rich, flooding and starting w/o choke.

Post by BaNZ » 11 May 2023, 13:49

I cleaned it so many times, I lost my count.

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knackeredMk1
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Re: Too rich, flooding and starting w/o choke.

Post by knackeredMk1 » 12 May 2023, 13:18

I don't know. Without being there it is very difficult. Carb is the area most likely to change. Replace the jets?

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BaNZ
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Re: Too rich, flooding and starting w/o choke.

Post by BaNZ » 12 May 2023, 17:26

Well, I don't really know, as I never replaced jets and they worked fine. I'm thinking of buying chinese PWK carb in testing purposes as I'm out of any other ideas.

Can jets really be the cause of such strange behavior?


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