DynaJet Kit

[Ranger_xs1100]

Does anyone know anything about the DynaJet Carb kits? I don't... but I have 1 and 1/2 kits that I'll never use. The package says it is for 1980-1982 XS1100 and XJ1100 for stage one and stage three, whatever that is?. The contents of the full kit includes 16 jets and 4 needles. the partial kit has 12 jets and 4 needles.. Most of the pieces are new. A few have been used. Any interest here? If so, I can post more pics and the instruction sheets. Or pm if you like and we can come up with a fair price for them. Thanks.

[Ranger_xs1100]

Oh... I guess it's DYNO JET... not DynaJet... just shows how much I know about them!

[DEEBS11]

Yes Ranger, I have installed several kits in all sorts of Japanese and American bikes. The different stages refer to the different states of engine air flow modification. Stage 1 is simple air filter flow modification such as a stock shaped K&N gauze air filter. The other higher stages refer to modifications that bring higher air flow through and engines such as high performance exhaust and individual pod air filters. Porting a head and hotter ignition are also considerations. When more air is introduced it makes the mixture leaner. A jet kit of any brand is used to calibrate the mixture ratio back to approx. 14.7:1 (1 part fuel to 14.7 parts air).

That being said, the kit includes main jets and adjustable needles. The needles usually have a thinner diameter to flow more fuel at certain RPMs. This is important: DYNOJET HAS A PROPRIETARY JET NUMBER SYSTEM. In other words a Mikuni #130 and a Dynojet #130 are different sizes. Totally uncool for the next owner to figure out what is in his carbs if he assumes the jets are stock and tries to modify. However, the dead give-away are the needles with adjustment clips. Beware.

Do they work? Yes, if installed correctly and calibrated correctly. Usually the smallest jet in the kit and the needle clip set at #3 position will give good initial results. I do not drill the CV slide anymore because it ruins the drivability on the street. Yes, the slide comes up fast for "drag racing" but it also flops back down too fast and makes the carbs very fussy.

[Ranger_xs1100]

Deebs, Great info and impressive knowledge! Thanks for sharing.

[Tonyxs11]

the best way to set up the dynojet kits is on a dyno (rolling road)

[DEEBS11]

This cross refence to show the size difference. XS11 carbs are Mikuni and the charts is "iffy" on the sizes. But it does show how proprietary jets differ from company to company. Many, many screwed up bikes out there from shade tree mechanics messing around with a little bit of knowledge. I just worked on a CB650 rack of carbs that was "professionally rebuilt" on eBay. No size markings or company (Keihin) stamps. Just cheap Chinese brass. All garbage. Thank you professional mechanic for making me waste several hours fixing your mess

.https://www.jetsrus.com/FAQs/FAQ_mik...ihin_sizes.htm

[oldyam80sg]

I had the Dynojet kit installed in my 80 SG back in 1986 and still have it in there . Stage 3 was for full exhaust and individual air filters.

[DEEBS11]

Speaking of Dynojets, today I was rebuilding a set of 82 CB650 carbs for a job I am doing. I got these off of eBay for a decent price. I open them up to start working and they had a Dynojet kit already installed. Notice how the needles have a very thin profile down low for add fuel richness just off pilot to midrange RPMs. The stock needle is on the right (from a different set of stock 650 carbs). You can change the position of the needle by moving the clip up or down making it richer or leaner. The stock jet is #118 Keihin. This main jet was marked 116 but it is a proprietary number and is actually about the size of a Keihin #122 according to the cross reference chart. I will set these up with no airbox, individual UNI foam filters and a MAC pipe. Should run tomorrow. The foam filters are used because this bike is driven in the New England winter. Lots of salt and sand.

[nsmark]

Recently purchased a stage 3 dynojet kit for a 78 XS1100. Apparently the kit is for the european version of the 78 XS1100 not the north american version. Does anyone know the difference in carburation between the two versions. Thanks.