Forum Donations
Search
VTF Google Search
 Click Here

DUAL Mikuni TM38 flat slides Part 2

P901 Single carb intake, FLAASH Cams, Super Charger, NOS.......
  • Advertisement

Post a reply

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: cozwurth » Tue Mar 06, 2018 6:09 pm

I just bought a pair of Mikuni VM38 N9's last night, and a 2-1 throttle cable last night. All of it should be here in a few days. Luckily I have a couple of people at work who have 3-D printers, so I should be able to get adapters made for the filter side if needed. Hopefully I can get them on and get it running by spring.

Dave
'84 Yamaha XV700 Virago
'85 Honda VF700 Sabre (SOLD)
User avatar
cozwurth
Junior Membership
Junior Membership
 
Posts: 61
Joined: Mon Dec 24, 2007 10:22 am
Location: Franklin, Virginia Flag

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Wed Mar 07, 2018 2:05 pm

You're at the wrong thread. There's a different thread on VM38-9 setup... with those you'll need VM38-200 inlet manifolds as the diameter is smaller. On the rear you won't need some 3d-printed part, but 54-63mm silicon couplers (as used on turbo-intercoolers)

Cheers,
Greg
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: cozwurth » Wed Mar 07, 2018 8:47 pm

nanno wrote:You're at the wrong thread. There's a different thread on VM38-9 setup... with those you'll need VM38-200 inlet manifolds as the diameter is smaller. On the rear you won't need some 3d-printed part, but 54-63mm silicon couplers (as used on turbo-intercoolers)

Cheers,
Greg


Thanks, Greg. I guess I missed that thread. I did search and found quite a few posts with the VM38-9 info, but didn't see a dedicated thread. Looks like you have put some pretty good info out there. Do you have a link to the thread?

Dave
'84 Yamaha XV700 Virago
'85 Honda VF700 Sabre (SOLD)
User avatar
cozwurth
Junior Membership
Junior Membership
 
Posts: 61
Joined: Mon Dec 24, 2007 10:22 am
Location: Franklin, Virginia Flag

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Thu Mar 08, 2018 1:23 am

As the search doesn't seem to work for me, there's a VM38-9 thread on www.tr1.de and there's definitely two or three of them on this forum, but I can't find them for the life of me.

But just open a new thread here in power-adder and I'll throw in what I have in the coming days, incl. manifolds and connectors and such.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Southclaw » Sat Apr 28, 2018 9:44 pm

When you fish the needle out of the slide, does the little washer snap in at the very top or very bottom of the slits on the needle?? I've got it set at the bottom but I just wanted clarification that I'm doing it right.

XV920 in central North Carolina, right around sea level, short 2 into 1 exhaust and a wide open air filter, I'll report back with my setup when I get it dialed in properly, I've got the air mixture screws out 2 turns but I'm still fighting with a rough and jumpy idle.
Josh. 1982 xv920 cafe project.

Southclaw
Senior Membership
Senior Membership
 
Posts: 132
Joined: Fri Apr 17, 2015 8:47 pm
Location: Raleigh, NC Flag
Bike year & model: 1982 xv920 virago
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: tymck7 » Mon Apr 30, 2018 11:47 am

For me, the perfect setting was to set the needle all the way up (the washer clips in at the lowest groove on the needle - so it sounds like you have it correct). Then I threw in a Q-4 needle jet (you'd probably be just fine with the Q-2 the carbs come with), and also a 250 mainjet. Runs perfect here in Idaho (2000 foot elevation). Air screws 2.5 or 3 turns out works for me, but the air's denser where you're at it sounds like, so 2 turns might be just fine. Does the bike rev well? Mine's a 920 with K&N filter, aftermarket 2 to 1 Mac exhaust.
'83 xv750 converted to '83 xv920..
Done: TR1 tank, removed stock airbox, 2-1 exhaust, brat subframe and seat, R6 front end, dual mikuni TM38-85's.

Plans: XT600 rear shock, 700 heads, rear wheel 17" 900 XJ Diversion complete with disk brakes, C5 ignition, BT-05 cam and anything else cool I read about on here.

Gracias a todos!
User avatar
tymck7
Junior Membership
Junior Membership
 
Posts: 55
Images: 6
Joined: Tue May 16, 2017 11:28 pm
Location: Meridian, Idaho Flag
Bike year & model: 1983 xv920
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: cafe45 » Sun Jul 01, 2018 12:57 pm

I will give you a little history on me and my 1984 XV700. The motor is completely stock with 21,000 miles. The old Hitachi carbs were corroded past repair. I tried rebuilding and let soak in an ultrasonic cleaner for 4 hours but still they would not work without choke on, plugged pilot passages. I am really not a big fan of Hitachi carbs. I built my own 2 into 1 manifold using a stock harley carb rejetted and it worked great except for an intermittent spit and hesitation on acceleration. Being that the intake tracks were not equal there was no way I could jet correctly. The front plug burned a perfect color the rear was sooty black. Very cool looking though.
https://www.youtube.com/watch?v=kqLu5A-qcpE&t=123s
I will tell you of my experience with the TM38-85. I read forum here and thought that I would follow suit from all the positive I read. It was these or the 34VM's that Greg Hageman uses. I emailed Greg (very nice and knowledgeable guy) to verify and it is the same kit Niche Cycle and a couple others are selling. Well this winter I decided on the TM's and purchased a set. I ordered a set of aluminum reducers from Mikuni Oz so that they would fit the stock boots and have the factory look. I made my own cables from bulk stock and ferrules I have. The carbs went on with no issues, however. Problem one came when I had to get a 90 degree adapter for the cable seat coming out of the carb top. The straight one would not work because it was hitting the frame backbone and I would have to tilt it to get it to work. Once the cables were made and routing was correct. I raised the needles as stated. Uni Filter on frame, I hit the starter button (no choke) and the motor came right to life. I installed my vacuum gauges and synced them. I adjusted the air screw 2.5 turns out (rpm’s hung at 3 turns out on decal) and set the idle. The bike ran great in and out of town and I was impressed. This was a big improvement over my last 2 into 1 setup. When I started the bike I would let it warm up for 30-45 seconds and then ride. I started to notice the bike was surging at around 3000 rpm. Bike ran great at top end (will go past 7000 redline) but I did notice if I backed off at full throttle and then gave full throttle it would really pick up. I pulled the plugs and they were black and sooty. I swapped the 22.5 pilots for 20.0 and adjusted the air screw. I noticed that now with 1 ¾ turn out the air screws the idle would hang on deceleration. This is telling me not enough fuel so I turned in to ¾ turn. The plugs still black and sooty after warm up. Then I thought maybe the float height was off, nope. I then stepped down to a 210 main jets, still black and sooty if left idle. Ran better at wot. Just for kicks I installed 200 mains. Ran good at wot but noticed mid-range was surging at around 3000 rpms. I lowered needles to lowest position, and surging improved but still drives me nuts because it it ever so slight but I notice it. 17.5 pilots the air screw setting is just able to keep the rpm,s from hanging on decel at ½ turn out on the air screws. I have been riding and tuning bikes for 40 years but never have been stumped like this. I went through 12 spark plugs trying to get correct readings. I tried everything to get the plugs from fouling at idle. I am at a loss because what I am reading on this forum this was the way to go. Maybe it’s just because it’s a 700, but I rather doubt that. So ….. what am I going to do? I am going with Greg Hageman’s advise and using the 34VM kit. I will let you know how it works.
User avatar
cafe45
Brand New
Brand New
 
Posts: 2
Joined: Mon Apr 07, 2014 7:00 am
  Flag
Bike year & model: 1984 XV700 Virago
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Mon Jul 02, 2018 2:55 am

You may want to go much smaller on the mainjet for a start, I had the same issue (well, sort of) on my Turbo and it was down to the fact, that my mains were so much too big, that it affected everything. Maybe start out with #170 mains and #20 pilots. (It's what I run in my VM38s on a highly tuned TR1, so it should get you somewhere as a starting point. )

Also make sure you bought the TM38-85, i.e. the two-stroke version runs a different needle and even though that can probably be tuned to suit, this would alter all the recommended settings.

Hope this (somewhat) helps.
Greg
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: cafe45 » Mon Jul 02, 2018 6:50 am

Thanks Greg, I will give it a try.
User avatar
cafe45
Brand New
Brand New
 
Posts: 2
Joined: Mon Apr 07, 2014 7:00 am
  Flag
Bike year & model: 1984 XV700 Virago
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Jeff0133 » Tue Jul 10, 2018 9:07 pm

How do you change the needle jets? Want to put Q4s in my tms but they seem to be pretty well stock in there...do you just pull on them with pliers?...I don't want to fck this up
Basket cases make the challenge interesting.
Xv1100, TM-38 flatslides, hayabusa front end, xs 750 tank, reserve tank/fuel pump delete, motogadget m-unit blue, antigravity battery...
More to come

Jeff0133
Junior Membership
Junior Membership
 
Posts: 9
Joined: Sun Jun 12, 2016 9:24 am
  Flag
Bike year & model: 1994 xv1100 basket case clean title
94000km
Needs love but I like'em that way...
1998 xv 1100 donor(no title)
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Thu Jul 12, 2018 12:53 am

You drive them out from the float chamber-side (GENTLY). Remove the washer between mainjet and the needle-jet casting and re-install the mainjet two or three turns. Normally some gentle tapping with the back of a screwdrive will unseat it. Them remove the main-jet and it should fall straight out.

When installing the new one, take not, that there's an alignment pin in the bore, which you have to align with a groove on the needle jet.

Hope this helps
Greg
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Jeff0133 » Thu Jul 12, 2018 6:07 am

Ok thanks, it is pretty solidly in there, didn't want to use too much force and crack the carb itself...
Now..the carbs keep wanting To pop out of the boots...Anyone else have this issue?
Basket cases make the challenge interesting.
Xv1100, TM-38 flatslides, hayabusa front end, xs 750 tank, reserve tank/fuel pump delete, motogadget m-unit blue, antigravity battery...
More to come

Jeff0133
Junior Membership
Junior Membership
 
Posts: 9
Joined: Sun Jun 12, 2016 9:24 am
  Flag
Bike year & model: 1994 xv1100 basket case clean title
94000km
Needs love but I like'em that way...
1998 xv 1100 donor(no title)
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Thu Jul 12, 2018 7:25 am

Tighten the clamps on the rubbers and sync 'em.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Jeff0133 » Thu Jul 12, 2018 7:59 am

Things is...I an bottoming out on the clamp.
Mayne i'll try a plumbing...wormscrew style clamp.
Basket cases make the challenge interesting.
Xv1100, TM-38 flatslides, hayabusa front end, xs 750 tank, reserve tank/fuel pump delete, motogadget m-unit blue, antigravity battery...
More to come

Jeff0133
Junior Membership
Junior Membership
 
Posts: 9
Joined: Sun Jun 12, 2016 9:24 am
  Flag
Bike year & model: 1994 xv1100 basket case clean title
94000km
Needs love but I like'em that way...
1998 xv 1100 donor(no title)
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Jeff0133 » Fri Jul 13, 2018 10:05 am

The wormscrew thingys worked...no more sucking sound from the boots or carb being pushed out so...that's good.
Starts first stab of the button,idles strong albeit fast.
Stutters and gets "flat" at 3/4 to WOT.
Needles at highest.mixture screw 2 turns out.
... suggestions?
Basket cases make the challenge interesting.
Xv1100, TM-38 flatslides, hayabusa front end, xs 750 tank, reserve tank/fuel pump delete, motogadget m-unit blue, antigravity battery...
More to come

Jeff0133
Junior Membership
Junior Membership
 
Posts: 9
Joined: Sun Jun 12, 2016 9:24 am
  Flag
Bike year & model: 1994 xv1100 basket case clean title
94000km
Needs love but I like'em that way...
1998 xv 1100 donor(no title)
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: nanno » Sun Jul 15, 2018 3:05 pm

Unless I am terribly mistaken, the mixture screw is an airscrew on the TM (it definitely is on the VM), so try turning that in by half a turn as a start.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 961
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
Sex: Male

Re: DUAL Mikuni TM38 flat slides Part 2

PostAuthor: Jeff0133 » Sun Jul 15, 2018 4:14 pm

Ok, will do.ordered 250 main jets and a Q4 needle jet as well from mikunioz...waiting on those.
Basket cases make the challenge interesting.
Xv1100, TM-38 flatslides, hayabusa front end, xs 750 tank, reserve tank/fuel pump delete, motogadget m-unit blue, antigravity battery...
More to come

Jeff0133
Junior Membership
Junior Membership
 
Posts: 9
Joined: Sun Jun 12, 2016 9:24 am
  Flag
Bike year & model: 1994 xv1100 basket case clean title
94000km
Needs love but I like'em that way...
1998 xv 1100 donor(no title)
Sex: Male


Previous

Post a reply


  • Advertisement

Return to Virago Help - Single Carb / Power Adder

Who is online

Registered users: Baidu [Spider], Canadian Star, creongr, Ekaminsky2007, Google [Bot], JesseEightSix, jozx7r, lukeholloway21, Mauzer12, Neckyzips, Psycrow