wobblegob Posted September 17, 2023 Posted September 17, 2023 (edited) This motor is reving fine till you get up a little in the revs, then its bogging ive stripped the carbs and im reackoning the emulsion tubes are goosed now they have B-0□613 stamped on them. Are they stock or dynojet? any ideas greatly received chaps cheers Edited September 18, 2023 by wobblegob Quote
Upshotknothole Posted September 18, 2023 Posted September 18, 2023 Should be stock. Dynojet used the stock emulsion tubes in their bandit kits. Quote
imago Posted September 18, 2023 Posted September 18, 2023 20 hours ago, wobblegob said: This motor is reving fine till you get up a little in the revs, then its bogging ive stripped the carbs and im reackoning the emulsion tubes are goosed now they have B-0□613 stamped on them. Are they stock or dynojet? any ideas greatly received chaps cheers What makes you think the tubes are the problem? Quote
Gsxrsam Posted September 18, 2023 Posted September 18, 2023 Stick a drill bit in tube so you can see if they are oval... usually splutters and farts at low revs if oval... 1 Quote
Upshotknothole Posted September 18, 2023 Posted September 18, 2023 Lowering the needles a notch is also a band aid fix for oval emulsion tubes. Quote
imago Posted September 18, 2023 Posted September 18, 2023 3 minutes ago, Gsxrsam said: Stick a drill bit in tube so you can see if they are oval... usually splutters and farts at low revs if oval... I've only ever seen one which was oval (found as you describe) which is why I asked as I've found a fair few ridged, bent or wrongly fitted needles. Not saying the OP is wrong, just that in my experience it's usually the needles rather than the emulsion tubes. Quote
Gsxrsam Posted September 18, 2023 Posted September 18, 2023 Just now, imago said: I've only ever seen one which was oval (found as you describe) which is why I asked as I've found a fair few ridged, bent or wrongly fitted needles. Not saying the OP is wrong, just that in my experience it's usually the needles rather than the emulsion tubes. It starts with that stupid plastic wedge on needle wearing, that leads to needle tilting and rubbing on emulsion tube.... 1 Quote
Upshotknothole Posted September 18, 2023 Posted September 18, 2023 2 minutes ago, imago said: I've only ever seen one which was oval (found as you describe) which is why I asked as I've found a fair few ridged, bent or wrongly fitted needles. Not saying the OP is wrong, just that in my experience it's usually the needles rather than the emulsion tubes. Certain carbs are worse than others for destroying the emulsion tubes. BST38s on the last of the slingshot 750s were notorious for it. I've also seen my share of destroyed needles, especially the aluminum ones. 1 minute ago, Gsxrsam said: It starts with that stupid plastic wedge on needle wearing, that leads to needle tilting and rubbing on emulsion tube.... Someone on here used to sell metal replacements for those plastic wedges, and I think they were for the BST36 carbs. Quote
imago Posted September 18, 2023 Posted September 18, 2023 7 minutes ago, Upshotknothole said: Certain carbs are worse than others for destroying the emulsion tubes. BST38s on the last of the slingshot 750s were notorious for it. I've also seen my share of destroyed needles, especially the aluminum ones. Someone on here used to sell metal replacements for those plastic wedges, and I think they were for the BST36 carbs. I've never had anything to do with those, so that probably explains why I've not seen much emulsion tube wear. A known fault like that can lead people down the wrong path sometimes because the fault and cure grow from a model/year specific issue to across the board very quickly. Again just personal experience, but I've found more knackered dynojet needles than OE. Probably a mix of poor installation and the material that they're made from. There have been a fair few carbs where people have changed needles, jets, tubes, float valves etc chasing a problem without cleaning the carb and it turned out to be shit in the drillings. 1 Quote
Upshotknothole Posted September 18, 2023 Posted September 18, 2023 10 minutes ago, imago said: I've never had anything to do with those, so that probably explains why I've not seen much emulsion tube wear. A known fault like that can lead people down the wrong path sometimes because the fault and cure grow from a model/year specific issue to across the board very quickly. Again just personal experience, but I've found more knackered dynojet needles than OE. Probably a mix of poor installation and the material that they're made from. There have been a fair few carbs where people have changed needles, jets, tubes, float valves etc chasing a problem without cleaning the carb and it turned out to be shit in the drillings. I always check the needles first, mainly because I can usually get them out without remove the carbs from the bike. Also if the needles are knackered, the tubes are most likely gonna have some wear as well. 1 Quote
Andicog Posted September 20, 2023 Posted September 20, 2023 Mine were oval, they caused a stutter when rolling back on the throttle, dropping the needles a notch cured it for a while. 1 Quote
jonny1bump Posted September 20, 2023 Posted September 20, 2023 I was getting through set of imusion tubes every year. The dynojet tubes last 5 minutes always use stock suzuk. I knew they were gone, the moment coming out slow corners it hesitated at full lean, not pleasant. 2 Quote
Upshotknothole Posted September 20, 2023 Posted September 20, 2023 The last time I contacted Dynojet for replacement emulsion tubes, they wanted me to pull my tubes out of the carbs and take photos for them. I know the tubes are worn, I already had to lower the needles to help with the bogging in the mid range. And I'm not pulling the carbs off a running bike that I ride all the time to take photos for them. Just found a set of Mikuni emulsion tubes on Eblag for $40 shipped, looks like I'll be going back to a Factory Pro kit. Eventually this 750 will get flat slides and I won't have to deal with this crap as much anymore. Quote
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