Carb Jet Compatability

GoldenMotor.com

BikeMPG

New Member
Jun 10, 2013
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SLO
Hi there I have a question and it is will jets advertised as being "perfect for" the NT Carb work ok on other carbs? Specifically the RUNTONG, Dellorto Clone or what is commonly referred to as the HP Carb. It seems to me that many of these jets are the same design. 5mm thread is pretty much the factor correct. Now I understand that this idea isn't exact but in general it seems to me that the average 5mm thread jet should work in the NT Carb, HP Carb, Clone of the Mikuni round slide and probably others. Here is a link to the type of jets I'm considering here.

http://www.amazon.com/Jet-Kit-Motor...SMYrt4L&dpSrc=sims&preST=_AC_UL160_SR160,160_
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
Most the carb's for these engines will use the 5mm thread size jets, but there are a few that use the 6mm thread diameter, best to take the jet out and check before ordering just in case you got one of those oddball size with the 6mm jets.
If you can't find the right size you need on ebay or from other vendors, http://www.motorcyclecarbs.com/ can become very helpful and will most likely have what you need, they are a bit pricy but they also only sell the genuine name brand jets which are far more accurately drilled than the ebay China made jets.
The other alternative is to get a set of micro drill bits and a soldering iron so you can go up or down a size without having to buy a jet or wait for an order to come in....
 

BikeMPG

New Member
Jun 10, 2013
7
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SLO
I was reading up on the use of solder and drilling. I drilled the stock jet on the stock NT that was on my engine and it did OK. Then I did the same to the HP/RT Dellorto clone and it lost top end power. I thought that drilling the jet on the RT had changed the geometry of the jet unfavorably. I guess there isn't much geometry there to damage (like a convergent/divergent) thing. I was having a issue with a loss of power (bogging) once the engine was at full running temp and full throttle. Switching to the RT from the NT helped but the loss of power seemed to be present a little at times. I'll see about doing threads in specific areas of the forum about the particular issues that I've been working on. My China Girl is a ****ed up beotch maybe I'll blast up some pics to get back at er'.






r.ly.
In spirit as much as is best for me as far as I'm concerned.
 

BikeMPG

New Member
Jun 10, 2013
7
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SLO
Where is My Freedom of Speech and Press? Oh this is family website huh? Where's my manners. Sorry bout that. .flg.