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Discussion Starter #1 (Edited)
OK i Just finished a bunch of maintenance and mods, valves adjusted, oil change, antifreeze change, de-baffle exhaust, re-jetted carb (Dynojet needle DN0106, 50 idle, 165 Main with emulsion tube all HD) and scooterized intake cannot believe the difference in power and highway cruising but as with anything there is a drawback at least for me and maybe you guys can help me out. I have my dyno-jet needle set at 2nd notch from top with 2 washers and air mix screw is at 2 1/2 turns, plugs after 400 KMS are nice and tan and there is absolutely no backfire from exhaust, occasionally I get a cough from intake when at a stoplight or intersections where I must completely stop and I blip the throttle (habit I suppose) but that is rare and the only hiccup when running, I know moving up a notch on the needle leans out the mix and down makes the mix richer, but not sure how that would effect throttle response, right now the bike is super responsive, maybe a bit too responsive, on the highway it's perfect but in town it seems that the throttle is way too touchy. I am very aware of over throttling and I am talking about fractional movements on the throttle and the bike wants to launch, hit a small bump at slow speeds in 1st, 2nd or even 3rd gear and that is transferred to my hand resting on throttle rocker and bike surges forward really touchy but very smooth on highway, make driving in traffic a real pain and I would like to dial that down just a bit, any suggestions would be most appreciated, BTW I have already done a 17T to 18T front sprocket swap and intend to do the rear swap to 40T at a later date, this will calm it down some but just put a new chain and sprocket set on last season and it's only got 1200K on it so far so it's not going to get changed for a while. Any carb tuning tricks I might employ would be appreciated.
 

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I have an '03 1500 and tried about every jetting combination within reason. FWIW, I finally settled for a 48 pilot 2 1/4 on the screw and a 165 main. As far as the needle goes, I stayed with the stocker, but used 2 washers to raise it up 30 thousands. I am running a TAK and 3" Roadburner pipes. I ended up going into the carb 4 times before I got it dialed in. Ride for a while and you will feel what needs to be tweeked.
 

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Discussion Starter #3
I have an '03 1500 and tried about every jetting combination within reason. FWIW, I finally settled for a 48 pilot 2 1/4 on the screw and a 165 main. As far as the needle goes, I stayed with the stocker, but used 2 washers to raise it up 30 thousands. I am running a TAK and 3" Roadburner pipes. I ended up going into the carb 4 times before I got it dialed in. Ride for a while and you will feel what needs to be tweeked.
Thanks for that insight, I know it's a tweaking thing but didn't want to start changing too much at once and start a yoyo effect, I have exhausted my mod budget for the year so I am hoping to get this dialed in without buying more jets and I definitely do not want to remove the dyno-jet needle as it's the only part I used from a kit that cost me $80.00, at least not unless I have no other choice, I did forget to mention I also did the top side mod where you drill out the slider with a 1/8" drill, maybe a smaller hole would have been better any other suggestions are welcome, thanks.
 

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drilling a hole in the slider could be the problem, that could be making the slider very sensitive. What pilot jet size did you end up going with? the stock 48?
 

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Discussion Starter #5
drilling a hole in the slider could be the problem, that could be making the slider very sensitive. What pilot jet size did you end up going with? the stock 48?
165 main with emulsion tube and 50 pilot all are Harley Davidson parts
 

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you had to buy a Harley CV carb main jet because the Harley emulsion tube threads will not accept a CV Keihin main jet, the threads are different, but your pilot jet is not exclusive to Harley like the main jet is, your PJ is Keihin
 

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I think your problem is with both the drilling of the slide making throttle movement touchy and also your install of a 18T front sprocket, that 18 is what is probably causing your bike to launch from a stop because your gearing is set lower now and the bike will want to go farther on less RPMs. If you keep the 18T front and decrease the rear to a 40T, your highway cruising will use less RPMs and save fuel but your 1st gear get-go will want to launch the bike from a stop even worse
 

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the only solution to a 1st gear get-go launch from a stop using a 18T/40 sprocket combo, is the manage the clutch in a way that eases the clutch lever out slowly from a stop until you get moving because that bike with a 18/40 is going to want to launch forward very quickly
 

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consider a sprocket ratio where the front and rear have same teeth, like 18T front and 18T rear, that combo will made a bike want to take off into outer space on a single RPM of the motor
 

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Discussion Starter #10 (Edited)
I think your problem is with both the drilling of the slide making throttle movement touchy and also your install of a 18T front sprocket, that 18 is what is probably causing your bike to launch from a stop because your gearing is set lower now and the bike will want to go farther on less RPMs. If you keep the 18T front and decrease the rear to a 40T, your highway cruising will use less RPMs and save fuel but your 1st gear get-go will want to launch the bike from a stop even worse
Yeah I agree with this observation, while swapping to an 18T from the 17T front it did make highway cruising better but it did not help out in 1st even before the performance mods, I have been running the 18/42 only because the previous owner did no maintenance on chain and sprocket, he replaced a worn rear (42T) just before I bought bike and left old stretched chain and worn front on, made what was seen look new and said entire drive and sprockets had been replaced, anyway I replace chain and front within 1 week of having bike last summer without this problem, well not as noticeable I suspect, but now that I have done these power mods (re-jet, scooterize, de-baffle) it has become an issue, I can ride the bike just have to be careful in traffic for now, thinking about going belt drive (which will essentially give me the 18/40 drive ratio and should help out this problem) so don't want to toss any more cash into the chain and sprockets, and they are basically new anyway, cheaper solution is buy a used slider that is not drilled and see where that goes I suspect. I feel that the bike is running great otherwise so am reluctant to make and further air/mix adjustments or needle adjustments, appreciate the responses and insight provided, will update when I solve this minor glitch, thanks again. Here is a pic of the scooterized intake:

029.jpg
 

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if you want my opinion, I would leave the carb alone, don't touch the needle or the jets, and just adjust your riding style with what sprockets you have now, the 18T/42, Try letting out the clutch slower from a stop and see if that helps a bit. The only solution for the slider is to buy a new one and that means removing the carb again so would live with what you now got as best you can. For a belt have a story share, I had a '02 800 and put on a scootworks belt drive and broke/snapped 2 belts passing vehicles on the highway, sold that bike and new owner also broke/snapped a new improved belt trying to throttle/merge into traffic, so am not a fan of belt drives on an 800 anymore, keep the chain because if you are on a trip somewhere and snap a belt you are in deep trouble. The belt ration on the 800 is 2.22 ration same as an 18T/40 sprocket combo
 

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I've been thinking about your bike and I am going to say that I don't think the problem is with your drilled slide, I think it's the sprockets
 

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Discussion Starter #13
if you want my opinion, I would leave the carb alone, don't touch the needle or the jets, and just adjust your riding style with what sprockets you have now, the 18T/42, Try letting out the clutch slower from a stop and see if that helps a bit. The only solution for the slider is to buy a new one and that means removing the carb again so would live with what you now got as best you can. For a belt have a story share, I had a '02 800 and put on a scootworks belt drive and broke/snapped 2 belts passing vehicles on the highway, sold that bike and new owner also broke/snapped a new improved belt trying to throttle/merge into traffic, so am not a fan of belt drives on an 800 anymore, keep the chain because if you are on a trip somewhere and snap a belt you are in deep trouble. The belt ration on the 800 is 2.22 ration same as an 18T/40 sprocket combo
That story isn't encouraging about the belt drive, I will have to do more research now before I invest in that system, most new cruisers all come with belt drive, must be something specific to the VN800 setup causing the problem, maybe I will just swap the rear sprocket with a new 40t the chain and front are relatively new and show no wear or stretch, going to price a new sprocket tomorrow. Thanks for the shove in that direction, will let you know how it works out.
 

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I should clarify that the belt drive I installed on my 800 was a scootworks belt, and I don't think they made the belt strong enough, the new cruisers that come out with belts are probably much stronger, if you want a belt, the benefits are they are almost maintenance free, quiet, need no oil like a chain or grease on splines like a shaft drive, before you buy a new 40T rear sprocket, research belt makers for more information to make a decision, I only had a bad experience with scootworks, but stay away from scootworks belts
 

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Discussion Starter #15
I should clarify that the belt drive I installed on my 800 was a scootworks belt, and I don't think they made the belt strong enough, the new cruisers that come out with belts are probably much stronger, if you want a belt, the benefits are they are almost maintenance free, quiet, need no oil like a chain or grease on splines like a shaft drive, before you buy a new 40T rear sprocket, research belt makers for more information to make a decision, I only had a bad experience with scootworks, but stay away from scootworks belts

Been reading lots of posts on the belt drive and VN800, have not found anything other than Scootsworks that sell a complete system, lots of so so reviews on belts breaking and older design belt tension causing bearing wear on output shaft, really not finding anything that has me confident in doing the conversion, chains are not that bad actually just maintenance pigs, think I will stick with the chain for now got other mods I can spend that 1K on that will not effect reliability (I will get a cheapo ebay chain and toss in saddlebags just in case I need it on the road), not willing to shell out close to 1K after s/h and currency conversion for a system that has been known to fail and cause problems, thanks for the heads up.
 

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anyway I replace chain and front within 1 week of having bike last summer without this problem, well not as noticeable I suspect, but now that I have done these power mods (re-jet, scooterize, de-baffle) it has become an issue,
here it is, I was re-reading this thread again and found your problem. You did the chain and front sprocket change and did not notice this problem until you did the drilling of the carb slide mod then it became an issue, I think you increased the size of the hole too much that is causing your throttle to be very touchy now. I think the solution is to replace the slide with a stock one and don't drill out the hole. But that means buying a new slide and removing the carb which you might not want to do again.
 

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The Scooterizing PDF file instructions on Russian Wolf's site in my opinion should remove a couple things from the instructions.
First is the mod to drill out the 800 carb slide and increase the hole size, that mod should be discontinued because it can cause a problem with an overly sensitive throttle as you now are experiencing. The stock size hole in the slide works just fine and Kawasaki engineers designed that hole size and placement for a good reason and increasing the size of that hole or drilling out a new one does not take advantage of what the engineers know what works best.
The second thing that should be removed from those instructions is the optional use of the Dynojet needle DNO313 for a Vulcan 1500. I am using that needle in my 800 now and I'm having big problems getting the motor to run right. It's running way too rich. I called Thunder Mfg where I bought my air intake and was told that the DNO313 needle is not suppose to be used in an 800, it's for a 1500 and the length and taper is different and that needle is what is causing my problems. Even with the lower e-clip placement on that needle to raise it up as per Scooterizing instructions does not work. And I can verify for a fact that it does not work. Those instructions should only recommend the 800 Dynojet needle DNO106.
 

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Discussion Starter #18 (Edited)
The Scooterizing PDF file instructions on Russian Wolf's site in my opinion should remove a couple things from the instructions.
First is the mod to drill out the 800 carb slide and increase the hole size, that mod should be discontinued because it can cause a problem with an overly sensitive throttle as you now are experiencing. The stock size hole in the slide works just fine and Kawasaki engineers designed that hole size and placement for a good reason and increasing the size of that hole or drilling out a new one does not take advantage of what the engineers know what works best.
The second thing that should be removed from those instructions is the optional use of the Dynojet needle DNO313 for a Vulcan 1500. I am using that needle in my 800 now and I'm having big problems getting the motor to run right. It's running way too rich. I called Thunder Mfg where I bought my air intake and was told that the DNO313 needle is not suppose to be used in an 800, it's for a 1500 and the length and taper is different and that needle is what is causing my problems. Even with the lower e-clip placement on that needle to raise it up as per Scooterizing instructions does not work. And I can verify for a fact that it does not work. Those instructions should only recommend the 800 Dynojet needle DNO106.
I have concluded that it's both the slider and the 42T rear sprocket mated with the 18T front, I got a hold of a friend that has the same 800 as me, he had a spare carb so I borrowed it (yeah like he borrowed my compression gauge 9 months ago and I have never seen it since) OEM hole and perfect diaphragm, popped it into my carb (carb did not have to come off just tank had to be removed) and throttle was way less sensitive but still felt like it wanted to launch in 1st and 2nd, so I am doing the sprocket next season as I will be going for Hernia surgery July 22 and that's the end of my riding season, well at least until mid September from what my Doc says, going to ride bike like this until the surgery, didn't fell any drop in torque with the OEM hole in slider either, agree with you this should either not be in instructions, or should be noted as an additional mod to be done afterward if necessary and warn against throttle sensitivity. Too many changes being made at once makes it very hard to diagnose problems.

Sure glad I used 800cc engine needle rather than the one for the 1500cc engine, found several for 1500cc about $20.00 less than the 800's glad I dodged that bullet. Thanks for your input, good information to pass along.
 

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I heard, forget where I saw this, but when you increase the front sprocket by 1 teeth, it has the same effect as decreasing the rear by 3. So by that formula, your 18T/42 combo is similar to a 17T/39. One teeth change on the front has a huge impact on the ratio vs the rear
 

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ok I just got my new dynojet jet kit #2147 in the mail for my '05 VN800, in the kit box is the needle # DNO106 and dynojet main jets DJ130 & DJ134. I don't plan on using the main jets from the box.
I installed a 170MJ and removed the 50PJ that I had in the carb and installed the stock 48PJ. I have the carb on my work bench and waiting for the EZ-Just Mixture Screw in the mail before I put the carb back in the bike. The dynojet kit instructions say to put the e-clip on the 2nd notch from the top with 2 washers above the e-clip, and to turn the idle mixture screw out 3.5 turns from seated. There was no pilot jet in the kit so the 3.5 turns I assume must be with the stock 48PJ. When I had that VN1500 dynojet DNO313 needle in there with the 50PJ 2.5 turns with my bike in neutral, motor did not idle well and labored a lot when I increased throttle a bit. Do you think my bike will run ok this time?
 
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