jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Apr 30, 2012 0:00:11 GMT -5
just wondering what the difference would be? im going to be putting a BBK on my sunny first generation style scoot and was wondering if i should buy an aftermarked carb, wouldn't upjetting the unsealed carb i have be just as good?
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Post by Fox on Apr 30, 2012 3:07:12 GMT -5
Sure. Up-jetting the carb you have would be a better option. An aftermarket carb is just a stock unsealed carb so it too would need up-jetting most likely unless by some odd chance it comes with a bigger jet installed already which is doubtful... Lowering the needle clip setting in a standard carb can be enough sometimes. Jetting is something that cannot be defined as simply as order this jet or that carb. It's a delicate trial and error thing. Plug reads and incremental changes are what gets you there. It might take trying several jet sizes and playing with the clip to get it right. Lowering the clip = richer  |
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Deleted
Deleted Member
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Post by Deleted on Apr 30, 2012 9:43:41 GMT -5
wouldn't upjetting the unsealed carb i have be just as good? not if its a junk carb that will never run right nomatter what jets you put in it: OEM sealed carbs that have been unsealed, fake keihins. Carbs cause tons of headaches. I put a new genuine keihin carb (that comes jetted 85/33) on every bike that is mechanically straight but runs like shit. Fixes it every time. the weak link on these bikes is carbs. I have a whole big box of parts carbs in the shop. the only 4t bikes i have seen with carbs that were worth a damn are my new 72cc bikes (which are now a thing of the past since their EPA cert ran out). |
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Deleted
Deleted Member
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Post by Deleted on Apr 30, 2012 10:32:58 GMT -5
Also I stopped unsealing carbs when the last one i did had nothing to adjust under the plug they put on the A/F mix. I have done ones that never ran right after unsealing and changing the jets too. Unsealing is likely wasted effort.
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jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Apr 30, 2012 16:20:12 GMT -5
oh wow, thanks for all of the great information guys!
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Post by jmkjr72 on Apr 30, 2012 17:37:42 GMT -5
the other thing to consiser when dealing with the oem carbs you never realy know what jets work right
if you get an after market brand name carb or one of the good clone aftermarket carbs you know what jets work properly with your carb and you have repeatable jetting
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Post by stepthrutuner on Apr 30, 2012 19:14:19 GMT -5
How come none of you 4t guys don't plug slide carbs on those dudes? Lotsa small 4t atvs come stock with em don't they?
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Apr 30, 2012 21:43:43 GMT -5
CV carbs are more forgiving and seem to work better on 4ts....thats been my experience anyway.
I am sure they know the sealed carbs cause issues and I have seen some stuff about throttle body injection (TBI) but who knows how good that will be or when it will happen. I have visions of needing to replacing all that with a good quality CV carb too lol.
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