What size main jets are you using? Stock 750 w/ K&N.

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Just looking to get advise on what main jets to run in a stock motor (with a K&N) Dosn't seem to be as fast as it should. I had 220's in the carbs, and my guy who rebuilt them put in 230's. It's defiantly lost a bit on the top end.

I'm using the autolite AP64 plugs BTW. Seems to like them better than the AP63's...

Last question is, since I've never actually changed the main jets, is there any good write up on how to do it?
:roll:

Thanks guys!
Just fitted new K81 tires, and a new chain today.
Did the ton for the first time on this one today, that was a rush!
But I really want to get the acceleration spot on, that's why I need to know about the jets.
Thanks again.
 

L.A.B.

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nidyanazo said:
Just looking to get advise on what main jets to run in a stock motor (with a K&N) Dosn't seem to be as fast as it should. I had 220's in the carbs, and my guy who rebuilt them put in 230's. It's defiantly lost a bit on the top end.

To determine the correct size main jet it will be necessary to do some "plug chops". http://faq.f650.com/FAQs/SparkPlugFAQ.htm#Plug >Plug Chops (and how to do it)

nidyanazo said:
Last question is, since I've never actually changed the main jets, is there any good write up on how to do it?


Two ways, either remove the float bowl drain plugs, insert a small socket and unscrew/replace the main jets, or remove the bowl and unscrew/replace the jets. You don't even have to remove the carbs.



Other useful Amal info:

http://www.oldbritts.com/amal_tun.html

http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html

http://www.hitchcocksmotorcycles.com/am ... nc_ht.html

I find 220s are the correct size for my 850 fitted with custom filters & peashooters.
 
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Thanks a bunch LAB!
I fitted the 220's back in- took 15 mins...Easy.
Bike runs much better now.
There was a air leak coming from the manifolds, so some new gaskets w/sealant solved that.

Thanks again!
 
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