Tecate carb options-

[mudbogger]

Just wanted to let the Tecate fellas here in a carb swap that's pretty sweet IMO.I have recently been wrenching around ideas for replacements carbs, I purchased a 34mm VM off ebay, but it didn't fit the intake from JESWINEHART well, so I came across a 35mm PWK Keihin CARB and it fit's like a glove in the intake and stock air box.I also was able to use the stock elbow off the original carb lid on the Keihin carb,here's a link to my write up on the mods, thought it might be of some help to the Tecate riders here.

http://www.3wheelerworld.com/group.p...&pp=10&page=19


The stock internals in the 35pwk matched perfectly with my motor, which is all new OEM bore, piston,head.Idles, smooth, slow jet is just right for the motor, 1/4 to half throttle crips, response perfect, I need to install rear shock and do plug chops for top end,I'll post that in the future but so far, the carb is a great mod that really does not need alot of re-working internally to get a nice performance upgrade.

[Vootie]

Interesing, I have a 35 pwk on my blaster, maybe I'll pull it and put it on my tecate. Right now I have a 36? pj that I'm having issues attaching the throttle cable to. Thanks for the info.

[mudbogger]

my pleasure, look at the link for the stock elbow mod, it was easy.You'll need a snap ring kit,and some pliers,a spacer of some small washers,15/16 drill bit, flare kit for brake lines,and some time.

[mudbogger]

I have been working on plug chops with this carb,it came stock with a 160 main,I have increased this up as I did the chops, I currently have a 178 main jet in there and it is way to lean still.It is totally starving for fuel on top end, it flattens out big time with the current main in it, plug is white, no burn pattern at all, need a bigger jet for sure.In hindsight it might be better to install a larger carb for the motor as the short stroke makes fuel so important,and the V-FORCE reeds with stuffer should help with proper fuel intake.We will see if the larger main installed will make the carb come alive, I am hoping the PWK will perform as advertised,I do like the smaller carb for the bottom end which I do need.I also am running 13-44 gears which does kill the top end too.

[mudbogger]

ordered a jet kit for Kiehin from ROCKY MTN, with my 'frequent buyer points' it was only 100 bucks with free shipping, kit is nice, 5 of each jet from 125-210.Will post options when I get them in here.

[Vootie]

What motor mods do you have other than the VF3? Just curious as I'm about to order a bunch of jets and kind of want a ballpark to start from. Also, fyi, jetsrus.com sells individual jets much cheaper than buying a jet kit. Once you get the PWk dialed in, it's a great carb, not nearly as finicky as the older PJ's.

[mudbogger]

What motor mods do you have other than the VF3? Just curious as I'm about to order a bunch of jets and kind of want a ballpark to start from. Also, fyi, jetsrus.com sells individual jets much cheaper than buying a jet kit. Once you get the PWk dialed in, it's a great carb, not nearly as finicky as the older PJ's.

Not alot, just the reeds, the bore is a 70mm,35mm PWK carb,stock expansion chamber with DG SILENCER, bottom end stock,stock jug.I figured I could get the jets cheaper,but I have so many machines and all run Kiehins-I am constantly jetting and the extras could be handy on rides.

[Vootie]

Ahh, gotcha, jet kits the way to go if you have multiple Keihins. My motor is basically the same setup, minus the reeds. I did some plug chops today and found a 155 main came back pretty good. I ordered some slow jets, that's mainly where I'm having issues. Also, you mentioned in the tecate group that your comp was high. Any idea what stock compression should be? I checked mine today and it's 150 psi. I'm thinking that's kinda low.

[mudbogger]

ok having some issues.I can't seem to get the plug chops near what I need, it is way lean, I took the jets to the biggest I have which was a 215 main jet and installed, was way lean, after I drilled that main jet out with a 1/8 drill bit, still way lean,it pulls nicely on mid range to 3/4 then top end again flattens out.I tryed every position on the needle,different needles even, no change, the plug is white, no burn ring on the it,I took some pictures of the plug.I also checked the compression, it is 205 warm.The motor is new,V-FORCE REEDS with the stuffer installed,35 mm PWK 68 slow jet,stock needle,stock expansion chamber with DG SILENCER,all new piston, rings on jug done by US CHROME.Any help on this is greatly appreciated as I cannot understand why I am not getting fuel into this jug.These pictures are running 32:1 pump gas.Any ideas?The jug was not decked to my knowledge,it was re-plated, not resleved.Alos, the head to my knowledge was not milled, but I did not cc it and I used a OEM head gasket.I did lap the head and removed some material to make it flat, but would that cause the compression increase? I can't tell you the head has not been shaved as I purchased it used.

[DixiePlowboy]

Definitely sounds/seems like that would should be a huge main jet for your application. I had trouble trying to jet the new 39mm PWK I put on the '85 Tecate(Stock jug and ports, boyesen Pro reeds, DG and another coned headpipe alternating) I had last year. I couldn't get a plug color even with a 210 in it. Someone suggested that my choice of oil(Klotz Super Techniplate @32:!) was not allowing a good reading in just a run or two on a fresh plug.....like it was burning too clean.

I'm not so sure about that, but I do know that I never got a color on just a few runs.

I ended up having to go by feel...which seemed to be a #168 main in that 39mm......which was within 2 sizes of my buddy's '89 KX250 with a 39mm PWK. Definitely an unnerving undertaking!

BTW: I'm not suggesting you try to jump down as far as I did in jet sizes. Don't want a meltdown on my conscience.

[mudbogger]

I am using Amsoil mix with high test 32:1 PUMP GAS. I am very very nervous of leaning this motor out till it poofkabooms. I agree, I was totally shocked after I drilled out the 210(sorry not a 215) with that 1/8 bit I figured for sure it would be fouled, but it wasn't. I cannot see the 35 PWK being the issue as the stock size is a 34mm.Theres is no burn ring on the plug at all, I even cut 1 plug to look, nothing.Is it possible the mix is burning that clean? I understand from reading here these motors have a short stroke so massive fuel intake is needed for them,but why can't this carb do it? The carb is new-it will idle,I can adjust it on the idle/mid range circuits with great results.Perhaps a air leak in the bottom end sucking air? Motor is all new, cases lapped, Yamabond used in case-assembly.There has been a slight coating of black on the outer edges of the plug,but I attribute that to the re-plating-am I wrong? It is not carbon, looks to be paint honestly.

[Tecate 50]

Your compression ratio at 205 psi seems a bit high for unleaded pump gas IMO! You might wanna try throwing in some (leaded) race fuel! Just a thought.....

[mudbogger]

Your compression ratio at 205 psi seems a bit high for unleaded pump gas IMO! You might wanna try throwing in some (leaded) race fuel! Just a thought.....

will the race fuel make the difference? it seems to be a lack of fuel, not lack of octane-what will the higher octane do, it will just burn at a cleaner, higher ratio correct?

[Tecate 50]

Im not saying this is the answer, but just a thought. Race fuel reacts just the opposite when needed, the fuel burns at a slower rate, this may or may not darken up the plug! Lots of things come to play when tuning: jetting, timing, fuel, etc.....IMO with 205 psi I would definately be running some leaded race fuel. But again this may not be the answer......good luck and keep us posted!

[Maico]

Do a leak down check before you do anything more.