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to rich?????????????

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hey just pulled my plug to check it out and its black !!!!! the servace manual says this could be becouse its running to rich.ihave the baffel removed as well as the snorkel, stock jets #162 main and #62 slow any ideas why its to rich how can i fix this ,what can running it to rich do to the bike

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Hey Gregg,

Is this an XR250? I ask becuae mine had a 132 main jet in it.... you must be running an XR400 ?

Are you in the Marines now or former Marine?

I retired from the Navy 2 years ago after doing 30 years. I was fortunate to have promoted through the ranks E-1 to CPO (E-7) then CWO2, CWO3, LTjg, LT and retired as a LCDR.

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im still in just got back from iraq , i have a xr 400 97 sorry didnt put that in 1st post :thumbsup:

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Greg -

I'm not up to speed on the jetting of the stock carbs (I'm running a Mikuni), but I think it would tend to run leaner once you remove the baffel and open up the airbox.

Just a thought, but maybe you could be burning some oil?

Other folks here are sharp on the jetting issues, I'm sure they'll chime in.

Kevin

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i dont know your altitude in NC. but here in MO i ride at @ 7oo ft ASL.

i did gordon's mod (snorkel, header welds, drilled holes in baffle) and used his recommended 60/160 combo and found that was too rich. so 58/158 are about perfect for me. a really dirty airfilter can also cause richness. are you using the stock plug (NGK DPR8Z)? if you ride a cold plug at low PRMs it can cause a rich reading as well. leaky valve guides and/or worn cyl/rings can allow oil to enter the combustion chamber and make the plug black as well.

probably a few other factors i cant think of now that may cause richness...but 62/162 sounds pretty darn fat to me.

a 97? well it may be leaking oil...has it ever been rebuilt? maybe its time :thumbsup:

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My bad. I've got a '99 and '00. It seems they changed the jetting in 1998 to 52/142 at least thats what I'm reading.

I just helped my son's friend rejet his 97 xr400. It was way too fat at 162. I think we went to 52/158.

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Don't check plug color after idling.

Ride for 10 min or so(warm-up),then wide open trough the gears,kill the engine (NO idling) and check the plug.After idling the plug is always black.

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Don't check plug color after idling.

Ride for 10 min or so(warm-up),then wide open trough the gears,kill the engine (NO idling) and check the plug.After idling the plug is always black.

yep idling was the prob went riding all day last weekend and pulled plug after and it was a nice light brown . thanks for the help

:thumbsup:

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was going to say the same thing as xrmanu the only way to read a plug is if you kill it at the end or middle of a run with a fully warmed engine

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