Author Topic: what jet size should I install?  (Read 1598 times)

vermiselle

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what jet size should I install?
« on: June 01, 2018, 02:05:26 PM »
For my Kymco Like 50 I ordered a new 19mm carburetor because the original 16mm works badly.
My engine is original 49cc but without restriction (exhaust, air filter...)
In my original carburetor I have # 90 hand jet and # 35 pilot and work fine.
With my new 19mm carb, what jet size should I install?

Keep the #90 and #35 or increase?

Thank you!


mclark999

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Re: what jet size should I install?
« Reply #1 on: June 05, 2018, 11:01:58 PM »
For my Kymco Like 50 I ordered a new 19mm carburetor because the original 16mm works badly.
My engine is original 49cc but without restriction (exhaust, air filter...)
In my original carburetor I have # 90 hand jet and # 35 pilot and work fine.
With my new 19mm carb, what jet size should I install?

Keep the #90 and #35 or increase?

Thank you!

Which 19mm carb did you buy?  I just bought a Dellorto PHBG 17mm for mine and don't know quite where to start on the jet size.  I want to start rich, not lean, if possible. I got a TrailTech TTO to measure cylinder head temp to help me tune it. I'm going to start with a 78 or 80 main jet and see.
Denver, Colorado, USA 5,300 Feet Elevation

2007 Kymco People 50 2T
Tecnigas Trek exhaust
OEM variator with 6 gram rollers
OEM 16mm carburetor

eamartin

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Re: what jet size should I install?
« Reply #2 on: June 06, 2018, 03:57:28 AM »
Which 19mm carb did you buy?  I just bought a Dellorto PHBG 17mm for mine and don't know quite where to start on the jet size.  I want to start rich, not lean, if possible. I got a TrailTech TTO to measure cylinder head temp to help me tune it. I'm going to start with a 78 or 80 main jet and see.
mclark,  please tell me again, what were the symptoms of your stock carb which prompted you to purchase a Dellorto?  eamartin

mclark999

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Re: what jet size should I install?
« Reply #3 on: June 06, 2018, 01:53:25 PM »
mclark,  please tell me again, what were the symptoms of your stock carb which prompted you to purchase a Dellorto?  eamartin
I could never get it to start easily cold AND run well and start easily hot. With the Dellorto, I can choke it it as needed and adjust the carb more precisely.  That's the theory at least.

Sent from my VS988 using Tapatalk

Denver, Colorado, USA 5,300 Feet Elevation

2007 Kymco People 50 2T
Tecnigas Trek exhaust
OEM variator with 6 gram rollers
OEM 16mm carburetor

eamartin

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Re: what jet size should I install?
« Reply #4 on: June 06, 2018, 04:08:44 PM »
I could never get it to start easily cold AND run well and start easily hot. With the Dellorto, I can choke it it as needed and adjust the carb more precisely.  That's the theory at least.

Sent from my VS988 using Tapatalk
Thanks for the reply.  My Super 8 2t has the stock PB Keihin carb.  If I run it daily, it starts easily and runs well.  If I let it sit for more than a day it is next to impossible to start (kick or majic button).  Great compression and crankcase holds vacuum and pressure.  Less than 2000 mi.

mclark999

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Re: what jet size should I install?
« Reply #5 on: June 06, 2018, 05:15:53 PM »
Thanks for the reply.  My Super 8 2t has the stock PB Keihin carb.  If I run it daily, it starts easily and runs well.  If I let it sit for more than a day it is next to impossible to start (kick or majic button).  Great compression and crankcase holds vacuum and pressure.  Less than 2000 mi.
Yeah, cold weather starting and sitting both seem to be issues with these. One work around that sort of worked was to set the idle a little lean and then put my hand over the air filter snorkel to choke it more to get it to start.

Sent from my VS988 using Tapatalk

Denver, Colorado, USA 5,300 Feet Elevation

2007 Kymco People 50 2T
Tecnigas Trek exhaust
OEM variator with 6 gram rollers
OEM 16mm carburetor

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