Poor running

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badbannedbiker
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Bike owned: nc29 nc30 gsxr750 T675 CRF450
Poor running

Post by badbannedbiker »

Right....I've acquired myself a 73a sp project. Before I go buying Oring kits etc etc I thought I'd post a topic incase anyone has any ideas.
the 73a sp I bought has a running problem, It starts and idles fine but won't rev - if you give it a big handfull of throttle 8 out of 10 times it bogs and dies - and if you can tease the revs up high enough to pull away it then loses power and dies.
So far I have - changed the plugs (NGK CR8EK-s), taken the diaphragms out and cleaned the jets, vacuum slides and needles of some varnish using a specialized carb cleaner spray (haven't removed float bowls buts sprayed plenty of stuff down the jets) and checked the fuel tap and air filter. when you have the bike running and rev it the vacuum slides chatter quite a bit also.

Any ideas before I start stripping the carbs?

Cheers
jake_gsxr
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Re: Poor running

Post by jake_gsxr »

i'm pretty sure my bikes running cr9ek spark plugs so that might be having an affect???
badbannedbiker
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Re: Poor running

Post by badbannedbiker »

Diaphragms are a bit stretched at the top where they fit into the carb bodies and seal against the black top lid....? :?:

The ones I swapped out were 8's, and I'm sure thats what the manual said, can anyone confirm this?

Cheers
Gazz
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Re: Poor running

Post by Gazz »

Hi

I've taken this from a GK73A Service manual, hope it helps.

Image

Gazz
badbannedbiker
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Bike owned: nc29 nc30 gsxr750 T675 CRF450
Re: Poor running

Post by badbannedbiker »

where'd you get the manual may I ask? Would this make a massive difference? anyone want to buy a set of 4x cr8ek used for 5mins? :D
badbannedbiker
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Posts: 125
Joined: Fri Jun 13, 2008 6:25 pm
Bike owned: nc29 nc30 gsxr750 T675 CRF450
Re: Poor running

Post by badbannedbiker »

the bike had being sitting for a year or so,so I'm assuming its more likely to be a carb issue than the cdi dieing (can they just go for know reason?)

cdi maybe??

cheers
reggit
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Re: Poor running

Post by reggit »

Spark plugs won't matter at this stage. The 8 and 9 are just the heat rating of the plugs.

Most likely a blocked jet(s) in the carbs. I'd whip 'em apart for a look see.
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badbannedbiker
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Joined: Fri Jun 13, 2008 6:25 pm
Bike owned: nc29 nc30 gsxr750 T675 CRF450
Re: Poor running

Post by badbannedbiker »

thats the next step I think, got to get a o ring kit off variablevalvesuck. Any body know where I can find diaphragms and float gaskets? Is it worth me buying cr9's just yet as cr8's came out of the bike? Do you think its worth
spending £35 getting the cdi tested at this stage?
badbannedbiker
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Posts: 125
Joined: Fri Jun 13, 2008 6:25 pm
Bike owned: nc29 nc30 gsxr750 T675 CRF450
Re: Poor running

Post by badbannedbiker »

anybody know where i can find a rocker cover gasket?
Gazz
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Re: Poor running

Post by Gazz »

Try these guys for parts.

http://www.ridersmotorcycles.co.uk/index.html" onclick="window.open(this.href);return false;

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