[robare]

Is a Harley 190 Main Jet the same as a 190 Dynojet?

[kenfuzed]

Originally Posted by robare

Is a Harley 190 Main Jet the same as a 190 Dynojet?

Yes and No. The "190" is supposed to refer to the diameter of the hole, which in the case of a 190 would be 1.90 mm. There has been a debate for years as to both the accuracy and way the hole is drilled. Accuracy aside, two jets drilled at 1.90 will not flow the same if one has a longer inside bore or the other has a chamfered end.

The other difference with Dynojet brand jets is that for years they manufactured main jets that would only fit their brand of emulsion tube. The threads were different so you couldn't use the jet with a stock tube. To make matters worse the DJ tube was designed to work with their own clip-style needle. As a package deal all of these parts could work well if properly tuned, but once you mix or match with stock parts tuning becomes a nightmare. Later on DJ decided to switch back to standard OEM threading but are still not equivalent to stock jets.

Basically, if you have a DynoJet kit installed then go with DJ jets. If not, go with stock or stock equivalent jets that are designed to work with regular cv carb parts.

The only thing I use DynoJet parts for is recycling

[robare]

Thanks Ken,

I installed the CV Stage 1 tuner kit on my 2003 88B. What was already in the carburator looked the same. The needles looked the same, the slow jet and main jet where the same numbers. As far as I could tell the emulsion tube was also the same but I used the new one. The slide was not drilled so I drilled it and used the shorter/lighter spring. I was getting 47 MPG before and I now get 40 MPG so I think something needs to be checked again like the float level. Is there anything else I should check?

[wvak47]

I imagine you are set up to catch a bunch of comments on this thread. The To Drill or Not To Drill debate will kick off again. Being one of those that has suffered from the slider stutter I am one vote for the Not To Drill side. That slider gets into rebound mode and it is a real PITA. Basically it opens fast and hard, too fast and hard and over does it, then it can't hold and falls and falls too far, then it catches again and back open fast and hard. This continues until you let off the grip and bring it up slower. While it does this your fuel air mix is a mess and the motor runs like crap. Been there dealt with that and don't care to go back.

I equate the CV with the Quadra-junk carbs for cars. If tuned properly you won't get a better setup for the money. If not you won't have a bigger headache if you hit yourself between the eyes with a hammer.

A LOT of gimicks out there for both as well. Somethings are really best left alone and that is one HARD lesson for me to learn LOL. Good luck with that thing.

[hotroadking]

Yep drilling is a no no
Put the stock spring back in, more pressure less flutter,

what happens is as WV said the slide hunts when you drill and then especially drop in the weaker spring.


That means the needle jet is coming up higher and letting more fuel through right where your mileage is determined therefore you went from 47 to 40.

I'd put it back where it was...

[chucktx]

i agree with the above........

[08XModel]

Originally Posted by wvak47

I imagine you are set up to catch a bunch of comments on this thread. The To Drill or Not To Drill debate will kick off again. Being one of those that has suffered from the slider stutter I am one vote for the Not To Drill side. That slider gets into rebound mode and it is a real PITA. Basically it opens fast and hard, too fast and hard and over does it, then it can't hold and falls and falls too far, then it catches again and back open fast and hard. This continues until you let off the grip and bring it up slower. While it does this your fuel air mix is a mess and the motor runs like crap. Been there dealt with that and don't care to go back.

I equate the CV with the Quadra-junk carbs for cars. If tuned properly you won't get a better setup for the money. If not you won't have a bigger headache if you hit yourself between the eyes with a hammer.

A LOT of gimicks out there for both as well. Somethings are really best left alone and that is one HARD lesson for me to learn LOL. Good luck with that thing.

Quadra jet carbs were one of the best factory carb out their and easiest to tune and would run on extreme tilts. Haven't found another one that would run on tilts.

[fxdxriderleo]

If drilling is bad. Why does the stage one kit that kenfuzed designed have you drill the slide. My drilled slide works great. I think the problem with people drilling slides is " if a little helps alot helps more " type of thinking. When I put the kit in my carb, I had heard good and bad about drilling the slide. I finally said "If the kit was designed with drilling the slide as part of it I would do it." I used the bit that came in the kit and followed the instructions and couldn't be happier. The bike runs great, no slide flutter.

[chucktx]

kens kit does not increase the size of the hole, it cleans it up from a bad job of drilliing from the mfg. in years past the rule of thumb was to take it out a few sizes bigger to allow a quicker response. what that did was make the slide flutter. so, if using kens kit, yes use the bit supplied to clean the hole but dont enlarge it.........

[fxdxriderleo]

Thats all it seemed to do when I drilled it. It barely took all the color out of the hole. The instructions said not to go any bigger.

[wvak47]

Originally Posted by 08XModel

Quadra jet carbs were one of the best factory carb out their and easiest to tune and would run on extreme tilts. Haven't found another one that would run on tilts.

Read slower and you will see I agree with you. The CV and the Quadra Jets are both looked down on as "factory carbs" being inferior, but that is by the masses that are guided by marketing propoganda rather than FACTS. But like me daddy always told me, "Boy don't complain about lazy or stupid people, cause if it weren't for them we wouldn't eat". Guess if it weren't for those folks that like Hype the good folk employed by all these "better carb" companies wouldn't eat either LOL.

[robare]

I put the stock spring back in and checked the float. I was able to get in a couple of rides and riding single I got 42 MPG and double up I got 41 MPG.

If I drop the slow jet from 46 to 45 what will that do?

[robare]

I put in a Harley-Davidson 45 slow jet. The holes in the shaft area looked a little larger which would allow more air in the mix and I'm guessing lean out the overall fuel mixture. I am now getting 44 MPG with no noticeable loss in power riding 70MPH.

[chucktx]

be carefull.......going to lean can cause big problems.......