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CR85 2005 Bogging Down

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Hi All,

I have been following this site for a bit now it has been a great help, thanks.

I have bought my Son a CR85 2005 and at first it was running OK but as it has had a bit more running time about 5-7Hrs it has got worse, now it bogs down when starting of the line, I can screw it and get it going but the young bloke hasn’t got that confidence yet.

I converted it from a big wheel to a small wheel, started to run a little worse, checked the plug and it was a bit wet, tried to tune it to factory specs, replaced the gearing to get it back to factory for the small wheel combination, tried to tune it but found out it had different needle and jet which made factory tuning out so have tuned it to spec with that needle jet combination, still not much better.

Have checked carby right through float level/jets, air cleaner is clean, compression is ok, reads are tight and in good condition, new plug fitted.

I have just checked the gear box oil that was new when we have first started riding it and it is going black or dirty and smelling a bit fuely and oil feels skinnier (run time with new oil is about 5-7Hrs) there was only 2/3 of the amount that should be in there, so I suspect that the crank shaft seals a shot, or what else do you that could be causing this problem.

What is the best way to check this out as I don’t want to do a complete bottom end rebuild, I was thinking of replacing crank shaft seals by just removing the LH & Rh crankcase covers any other seals need replacing, I will replaced the clutch with a new one now that fuely oil has gone through it.

Does anyone have a good workshop manual (link) that shows exploded view of component , what special tools will I require  (just a fly wheel puller)

Any thoughts, tips or tricks would be greatly appreciated. Thanks in advance.

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Ours would push the right seal out so I used a little Honda bond on it you can also use crazy or super glue just use a little and glue it to the case. as for as jetting. use the stock jetting,, 142 main and I think the pilot was a 42, it may have the NBKF needle jet in it set it at the second clip from the top,, back when these bikes were bought new they stapled this needle jet inside the owners manual as an optional needle jet,

Edited by Foleyracing
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