Re-doing a jet kit

[MarylandMagnav45]

HI-

I just joined, and was about to post almost the same thing-

My bike is a '97, it has V & H pipes and the prev owner gave me a reciept showing the install of a :Dynojet" kit...

My symptoms are the outrageous amount of decel popping, plus I also have a "flat" spot where the throttle hesitates at about 5-6K RPM, especially if you roll off, then try to roll back on it hesitates then catches forward.

I'm thinking lean condition all around? Would the pilot screws help with this? Is this the same screws that are used for synch?

I am in Baltimore, I would love to team up with someone who could show me how to pull these carbs, I'm a little squirrley about trying it myself.

Another marylander...near baltimore...like me and Jleather than...wow....MOOT should branch out to MOOM lol.

I've pulled carbs before but I have never adjusted jets.

[LIMagna]

HI-

I just joined, and was about to post almost the same thing-

My bike is a '97, it has V & H pipes and the prev owner gave me a reciept showing the install of a :Dynojet" kit...

My symptoms are the outrageous amount of decel popping, plus I also have a "flat" spot where the throttle hesitates at about 5-6K RPM, especially if you roll off, then try to roll back on it hesitates then catches forward.

I'm thinking lean condition all around? Would the pilot screws help with this? Is this the same screws that are used for synch?

  It would probably help to know more about how your carbs are set up but to answer your question, no, the mixture screws are different from the synch adjustment screws.  Also, while opening the pilots a little may help with the decel popping it's unlikely to completely cure it.  Again, without knowing what's in there it's hard to speculate and without experimenting, you stay where you are.  Certainly worth a try but it does require a special "D" shaped socket tool to engage the screw heads.   I had some decel popping (not an outrageous amount) that almost completely went away after I went up one size on my pilot jets (from 40 to 42).  I had tried playing with the mixture screws but never saw much change. 

  The flat spot could be main jets and/or shim/clip position on the needles (most probably the latter) or might even be poor synchronization (although I would think you would have trouble across the rpm range if that were the case).  Adding a shim (or moving the clip down one notch) could help there.  As for pulling the carbs, it's not as big a deal as you may think it is.  I was very hesitant too the first time but as long as you work slow and take your time, it's completely doable (as many here will tell you).  I've done it twice now and the second time I had them off and on in under 2 hours (includes changing the idle jets and a lengthy phone conversation with my brother).  It's not something that I want to do over and over again (I'd rather be riding the damn thing after all) but I'm pretty happy I took the plunge.  My point is not to say I'm the worlds greatest motorcycle mechanic (I most certainly am not) but I do have the fine people here on this forum to thank for just about all that I've learned about my bike. I am humbled by their collective knowledge. 

  Incidently, I've got V&H pipes too along with a Factory Pro jet kit, which I think uses similar clip type needles instead of shims (just doesn't require any drilling).  Mine are set on the second notch (the recommended starting point for tuning according to Factory Pro) and I don't have any hesitation at all anywhere from idle to redline. 

[JLeather]

Alright, carbs are off and one is apart to see what I'm up against.  Here's the deal:

108 Main

40 Pilot

Silver aftermarket needle with 6 positions (I think it's a Dynojet needle).  The clip is in the third from the top with what I imagine is the stock shim under it, so there are 3 positions richer and 2 positions leaner

The idle screws were at 2 1/4 turns out.  BTW, someone slotted them so they can be adjusted with a regular screwdriver instead of the special tool.


Now, after reading through the extremely helpful link to other members' carb tunings, I can see that I'm way too lean at idle.  LJ's tune with a K&N and V&H is 110 Mains, 42 Pilots, 1 additional shim, and 3 1/8 turns out.  I think the bike was a tad lean throughout, but very lean at idle.  It had issues surging slightly at low constant throttle applications (like when trying to maintain 35mph through a school zone).

My plan is to pick up some 110 mains and 42 pilots for starters.  That oughta help richen me up a bit throughout the whole range.  For idle screws I'm going to give 2 3/4 turns a shot, thought I'm thinking it might take 3 before it's right.  I'm also gonna bump the idle back down to 1000 where it oughta be.  It's the needle I'm just not sure about.  Anyone know about what slip position would be similar to the 1 additional shim LJ was using?  I'm considering moving it one clip richer (third from the bottom instead of third from the top).

Ok, that's all for now.  I'm gonna go clean up things a bit and bag/label the bolts.  Anyone know if dealer's carry additional jet sizes?  There's also a shop a couple miles away that dyno-tunes.  I might give them a call tomorrow and see what they got.

[JLeather]

Oh, and since I'm off work tomorrow and not doing much Sunday I went ahead and yanked the rear cam holders off.  I'm gonna do the TSB this weekend.  I'll let y'all know how it turns out.  I'm also a little concerned about the level of wear inside the holders for an 11,000 mile engine.  Nothing severe, I'll snap pics and see what you guys think.  Have any of you had your cam towers off?  Also, can I do the fronts without draining the coolant/moving the radiator?

[matty]

Wow- lots of useful info here, I suspect my setup will need similar tweaking-

Does anybody have a comprehensive list of the tools required to do carb work on V45's?

[TLRam1]

Wow- lots of useful info here, I suspect my setup will need similar tweaking-

Does anybody have a comprehensive list of the tools required to do carb work on V45's?

You're looking for DG, if he does not show up, send him a PM.

[JLeather]

So, I was pondering something about my carbs today.  I went to a local place a picked up a set of 110 mains.  They look different from the ones I pulled out.  The ones I picked up had a little band engraved around the head, just like the ones pictured for 99101 Keihins on all the jet ID sites (makes sense, since that's what I was buying).  The ones I pulled out had no band around them and the head was a bit taller.  Since I've got DynoJet needles, it would make sense I've got DynoJet jets right?  They all come in a kit, and I don't believe this bike was dyno-tuned (or it'd run better) so they're almost certainly the DynoJet jets.  Is there a positive way to ID the DJ jets?

Now, here's the question.  The FAQ says that a DynoJet 108 (which I've got in the bike) is similar to a 112 Keihin jet.  Anyone know why that is and what validity there is to it?  I do know that my bike at WOT seemed to pull fine.  Perhaps I oughta keep the 108 DynoJet mains in there and just bump the idle jets and needle/idle screw settings?

[Greg Cothern]

I found that the Dyna-jet kit worked GREAT for me on my previous 96 Magna with the needle in the 3rd from top, 42 idle jets and the Dyna-Jet 100's.  Remember that the # on the jet can be specific to that manufactuer.
Several in the DFW area had ridden this one and all spoke of its throttle response and pull..

[JLeather]

Well, I did the cam holders.  And learned a couple lessons along the way.  Getting them out wasn't that bad really.  BUT, make sure that whichever holder you're taking off that cam is on compression (both valves closed) or when you take the holders off that cam will jump out of the head.

Here she is all torn down:




And the area of interest:




Started in on the cam holder.  First was the center to make sure I get a good start with that tiny little drill bit (1mm):




Then it was time for the teeny little bit:




And the finished product:




Did it to all 8, and the bit survived just fine.  The advantage of starting with the center is that I also end up with a nice chamfered hole as pictured to help the oil flow.  Deburred, cleaned (extra thoroughly), and ready to rock.  When I reassembled them I coated the journals with a bit of oil so it won't be a dry start-up.  Torqued everything down, checked it all out.  Ya know what?  That cam that jumped out of the journal earlier ended up being off a tooth in timing.  I didn't have time to address that, so that's where I guess I'm starting next time.  Atleast the drilling worked out great.

[matty]

Thanks for posting the pics- If no special tools are required, I am going to try and pull my carbs and see what the jetting situation is too.

[Lurkin]

The Dynojet jets ARE different then the stock Kiehin jets.  I would suggest not mixing 'em unless you know the differences between the two.

[JLeather]

Making some good headway on the Magna.  Had to wait for the new pilot jets to come in at my local store.  Also, some "lessons learned" during reassembly that would have made the job a lot faster.  Most notable, the aluminum plate above the carbs has a front and a back; it's not symmetric.  I was pretty bummed when I finally got the carbs back on the bike only to fid out that the aircleaner didn't fit    Anyway, I got it fired up last night and it sounded great, but I couldn't take it out yet because the clutch cover is still leaking (in spite of a new gasket).  I ended up leaving the DynoJet 108's in it, bumped the needles up a notch to 3rd from the bottom, put 42 pilots in it, and opened the idle screws to 2 7/8.  Throttle response sitting in my garage it much crisper, but obviously I can't tell anything til I get it out on the road.  Likewise with the cam holder mods, I won't know how well it worked till she's good and warm.

[JLeather]

Ok, test report time.  Got her back together and went for a good ride this weekend.  No cam rattle so that part worked atleast.  Anyone know what mark I'm supposed to put on the engine when I do the TSB?  If I ever resell it I don't want someone else thinking they still need to do it.

For the ride report, it definitely runs better.  Downhill decel pop is all but gone.  It smells a touch rich at idle, but I'm ok with that for now.  The most improvement was just off-idle where the bike used to surge and buck.  I went for a ~180 mile ride with my wife.  Riding was good (except I really need progressive springs now).  Only complaint is the mileage.  When the bike was too lean I was pulling ~40mpg hitting the reserve at right around 105 miles.  My first 2 tank fulls this weekend were almost 30mpg on the nose    I know from reading that some people get around that, and it was 2-up averaging 70-75mph with a bit of wind, but still.  That's a 25% reduction in mileage.  That sound right to anyone else?  I'm gonna check for leaks when I get home.

[TLRam1]

(unrelated) - Question.. Any chance you have a punch mark next to your S/N on the neck of the bike??

Hoot answers your question above.

[John Luttrell]

I believe the technical service bulletin called for a single punch mark to be added after the last digit of the VIN#.