Super Jet SN low end bog problem (video)

[Little Trumps Super Jet]

I posted a video before of riding and asked about what i need to adjust and tune to fix this, i run dual keihn carbs, 44s i think, so i thought id post a video to help see the problem. some help with prop choice would also be greatly apreciated, i have a 144 blu printed pump, unkown repitched propand blowsion trim. All answers and help are greatly appreciated


https://www.youtube.com/watch?v=y2LjcPhCoTE

 

[Superjetjim]

Sounds a bit lean/hard on the low end. Have you stripped/cleaned your carb bucket filters? Your pop off might be a little to high, seems to pull at the top end listening to the video.

I would try, one at a time, in this order:

1) check/clean internal filters
2) richen low end carb screw by 1/8 turn
3) lower pop pressure with lighter spring

Good luck.

Jim

 

[Little Trumps Super Jet]

ok thanks. i havent done anything to them yet, so i will try that next. do you think new needles are needed??

 

[wanderer1]

Don't see many Kehein setups on SJ's, but if they are then they are probably not 44's and don't think they will have an internal filter. Knowing what carbs you have will aid in tuning. Hard to tell from short video but could be lean, could also be some water in tank. Will hesitate and bog then clear out at high speed. Pull the tank and pour the last quart into a mason jar let it sit for 10 min (not in the sun). You will see the water, if any on the bottom. If you don't find any then great, couldn't hurt to clean the tank anyway. If thats not it then, next would be move onto the carbs for disassembly and inspection. This where knowing what carbs you have comes into play. Good luck.

 

[Little Trumps Super Jet]

so there 38s im guessing? they seem like nice carbs and look brand new, i had novis and mikunis before and liked them so im hoping to like these to and yeah i havent seen many of them. are they not very good carbs? worth selling? i was under the impression they were just as good as mikunis but correct me if im wrong

 

[Little Trumps Super Jet]

my tank is clear btw, i just cleaned it before i rode it because ive had that issue before and it had no water in it and it had fresh gas

 

[Superjetjim]

my tank is clear btw, i just cleaned it before i rode it because ive had that issue before and it had no water in it and it had fresh gas

Have you emptied your fuel/water separator?

 

[Little Trumps Super Jet]

yeah i did, no water other than a few drops

 

[wanderer1]

If you dont have water in the fuel,have cut your spark plug wires back,verified your plug color,cannot tune it by adjusting screws.Take the carbs off and go through them. Inspect and replace anything worn,pull everything out and clean it all. Check jetting and find out exactly what carbs you have (guessing don't do much good) BN,SBN,CDK,CDK2 etc. Order some larger jets and start tuning. Might as well check your reeds and cages for defects while youre at it.

 

[Little Trumps Super Jet]

They are CDKs. where do i find size identificatiuon on the carbs? Dirtbike carbs are more my background so any help is appreciated with these. and im aware you cant tune by adjusting screws. plugs are good and i have good spark.are these not good carbs?? should i consider selling them?

 

[Little Trumps Super Jet]

I just read the original posting from purchase to double check and yes it's got a set of cdk blue body carbs with the adjustable air filters on it sitting on a billet manifold with reeds and cages

 

[Little Trumps Super Jet]

cdk carbs worth selling??