Dynojet - why unpopular?

[wsn03]

Hi All

My slabby 750 F waa bought 30 off yrs ago. I lent a race bike to a guy for the TT who had raced the same slabby. Dynojet had worked on a better TT set up, the result was 1100 G carbs with either stage 1 or Dynojet kit (the mild one whichever it is)

 

To be fair it was a million times nicer than the flat-slides set up

Now I've been reading on here Dynojet are sold by the prince of darkness. It was a long time ago, we didn't have internet or colour tv, most of us still thought the earth was flat.

My slides had an extra airhole drilled by the rolling road man, standard mod i believe and made it even smoother. K&N filter

Question- why are Dynojet disliked on here. Im scared to change because i seem to have a pretty nice set up. Any suggestions? 

Thank you 

 

Thank you 

Edited January 30, 2022 by wsn03

[yantosh]

seen the needles destroy emulsion tubes, like little fret saws, I'd rather just take the bike to a good dyno guy, have him sort it out 

[Gixer1460]

1 hour ago, yantosh said:

seen the needles destroy emulsion tubes, like little fret saws, I'd rather just take the bike to a good dyno guy, have him sort it out 

Who, back in the day, would have advised a DJ kit ! The amount of hours required trying to get stock components to work is inversely proportional to just fitting a kit and having it work 95% of the time out of the box! Worn out a few DJ needles - never an emulsion tube! Mind you all the kits I used had both DJ tubes and needles! Yes a DJ kit can be spendy but no worse than 2hrs dyno time which would hardly get you anywhere with stock components IMHO. 

[wraith]

Put a DJ kit in the 38mm gsxr carbs that are on the kat, spoke to the Dyna lads in the UK told them what I was running, they sent me a kit I put it in and apart from one change of main jet worked first time. Done all the pissing about taking the bike for a run then changing something and the taking for another run and repeat.

Only once had a bike set up on a rolling road and that was years back at V&M and when they had the bike for a week and it still had a flat spot decided they are not worth the time/money, not saying they are all bad some very good ones out there. But me I'd got for a kit first.

[Mike711]

From memory there were issues with early DJ kts when the needles were turned leaving microscopic machining marks that acted like a tiny file hence the worn emulsion tubes. They later made them by drawing from solid leaving a smooth surface.

[wsn03]

Appreciate all the replies, thank you. I am now a little  wiser

[Upshotknothole]

Factory Pro also does a ton of shit talking about Dynojet all over their website. I used to live about an hour from Factory Pro and always used their jet kits because they were nearby, also preferred that they used factory Mikuni jet sizing, so it was easy to get spare jets if needed. Only recent experience I've had with dynojet was on the stock 38s on a GSXR750N, needles and emulsion tubes were totally shot, but no idea of the age.

[baldrick]

think the main reason they were so popular was because dynos were so scarce in the early nineties.