Tri-z mod jetting issue

[tippmann]

Ok im desesperated right now about jetting.

The z: 1985 tri-z bored to second oversize .5(i think) , wrench report phase 2 , dg exhaust , 38mm miku tm (flat) open lid on air box, v-force reed cage. All bearing , Seal Gasket are new. COmpression 180 psi

Carb: setting right now are : 560 main ,q-2 needle jet , 50 slow, cant remember the needle but its the one that was comming with the carb.

Problem: even at 560 after a plug test at 5 gear wot then clutch+ kill switch spark plug are white + he spitting prestone a good shot. while im riding it he seem to cut a bit on every gear like if he miss gaz.(white plug confirm) but from 450 to 560 its the same deal happen.

So some peaple told me that he could pull some air within seal or somewhere else so I used break cleaner all over the head, reed cage , base of the cylinder and the sound didnt changed. I only have the seal behind the stator to look but hes new.

I had some Issue with my guy who made me the mod to port and head shaving. it ended that i had to put a thicker base cylinder gasket so it raised my port approx. by 0.008 '' My squish test:0.033'' compression 180psi

some told me that its look like you needle jet is too small so even bigger the main jet im stuck by the needle jet that why bigger jet do nothing

that or my port job is ''pass over'' (not sure how to say this but port too big and its bad ) But when i test the Z seem to pull right.

So i hope some1 here will have a good idea to help me there. and if i have to change the needle jet with what i have to switch a q-3 q-5 or switch to a bigger size in letter? like r-2 ?

p.s he dont smell prestone burned and i swapped my oil she had no pretone in it too but she was already dark... but since i rebuilded the bike its the first oil i putted in maybe its normal,.

[badass350x]

Sounds like you need a bigger main jet, if the plug is white on top speed plug chop, your running lean on your top end! Your needle is your mid range for the most part!!!

[badass350x]

Also double check your timing ..

[El Camexican]

I’m not saying this is your problem for certain, but I did see what I am about to tell you happen once...

A guy I know put a set of 40mm Mikuni RS Flat Slides on a 1200cc Kawasaki. He started with 140 Round jets (a very common jet for large 4 strokes, works in almost all conditions) The bike ran bad, really bad and the plugs were white as bone. His engine builder/tuner (who I still think is an idiot) had him running all the way up to 175, or 180’s with the same problem. These jets could have drowned a 1500cc Pro Mod, but they couldn’t feed the mild 1200 enough fuel.

In the end the problem was the size of the manifolds. They were eventually stock in diameter and just stretched over the 40mm carbs. What this did was put an obstruction between the draw of vacuum coming from the engine and the orifice of the main jet. Essentially it didn’t matter how big the jets were the engine couldn’t draw fuel up from the bowl.
In your case we all know a 38mm works well on a 250 Tri-Z, but being that my manifold already came somewhat modified I don’t know how much restriction a stoker has, so you need to take a look at this on your set-up. If the inner diameter of the manifold is smaller than the inner diameter of your 38mm carb I recommend you match it up before worrying about your main jet.

Once you are done I’d consider going back to a 480 or 490 and trying it. All other things being equal a modified engine will sometimes need a smaller main jet as the flow has improved to the point that the motor is creating more vacuum and drawing more fuel out of the same size jet.

Oh, and make sure your float is set correctly and is allowing the main jet to get enough fuel. If it is too low this could also be an issue.

[tippmann]

You make me think about my v force 3 cage the cage is in 2 part andthe second lower the size here a pic i found
http://www.google.ca/imgres?q=v-force+3&start=141&hl=fr&sa=X&biw=1366&bih=637&addh=36&tbm=isch&prmd=imvns&tbnid=xpIbN6hweikO_M:&imgrefurl=http://www.nonolesgaz.net/admission-pipe-clapets/666-boite-a-clapets-v-force-3i-80-85-cr-et-derbi.html&docid=B4WxP5Z_2YL4RM&imgurl=http://www.nonolesgaz.net/666-298-large/boite-a-clapets-v-force-3i-80-85-cr-et-derbi.jpg&w=300&h=300&ei=Tb6ZT-rDN-Ta0QH02fSJCg&zoom=1&iact=hc&vpx=905&vpy=167&dur=742&hovh=225&hovw=225&tx=103&ty=111&sig=108742691676876797101&page=7&tbnh=143&tbnw=143&ndsp=24&ved=1t:429,r:16,s:141,i:145

think i had to remove this part ?

about the float high how can i set it ?

[El Camexican]

I don't have a V-Force cage, but someone here must. What size diameter is that round hole? What size is the hole in your rubber manifold? I don't do French, but it looks like the ad says "for an 85cc engine" Is your V-Force for a Tri-Z, YZ or IT 250 or something else?

[tippmann]

v303a for kx 125 04-08 wwith p682m petal who are softer ,, this set up used by some peaple here... but maybe i had to remove the second part that reduce the hole size.

[El Camexican]

Yea, I just went looking for a V Force for an old YZ and they don't list them. So again I ask "what does the opening of that hole measure? If it is less than 36mm it may be the problem. Also, did the cage come with a manifold, or are you using the stock Yamaha manifold?

[Mosh]

V force makes a larger stuffer for the Z cage. Typically we use it on the BB 310 kits. But maybe it may help you in this situation.

http://www.3wheelerworld.com/showthread.php/67963-Tri-z-billet-intakes-TEST-RESULTS-PAGE-4/page4

Now, awhile ago I told you I was concerned with your squish readings. I said nothing lower than .035" and, you would need race gas at possibly .045 of squish..Z's just dont like tight chambers. At least during all the testing I did, they didn't like it. It prevents them from over-revving something fierce. I am sure someone here maybe has an opposite opinion on that, but what works for one may not work for the other guy. Just too many variables from engine to engine.
I am not an expert on the issue, it is just what I noticed during testing of the domes for the coolheads.

Are you running race fuel at those readings on your engine? If not, you need to be IMO.

Lastly...I absolutely have no faith in a Mikuni Flatside carb..And I dont recall hearing many good reviews on them either. I would say you may be better off to go over to a PWK 38 mil.
Also look into the new Z billet intakes. They flow more, eliminate the boost bottle, and fit the larger carbs much better. They are available for purchase in the 3WW store.

I dont want you to buy parts you dont need, but I definately agree with the OEM intake boot being way to small for a ported engine built to breath. I also know that too tight of compression on certain engine designs inhibits top end pull. Lastly, there are better breathing top end pipes than a DG. The Phase 5 or Answer pipes seem to have a little more topend pull over a DG. The Dg will work ok for you but if you find a good deal on one of the ones I mentioned try it.

[tippmann]

Ill start by buying some octane this next monday i have sone test to do before buying part at high price again but about the stroker if the v force you grinded it ?

[tippmann]

If i put back the hold reed cage who dont have the stuffer or i simply remove the stuffer off the v force cage then done a wot test with my 560 main jet who is probably way too big ill see if the stuffer is too small ?if my spark plug getting hella wet after this try it mean that im stuck by the v force stuffer size

[El Camexican]

If i put back the hold reed cage who dont have the stuffer or i simply remove the stuffer off the v force cage then done a wot test with my 560 main jet who is probably way too big ill see if the stuffer is too small ?if my spark plug getting hella wet after this try it mean that im stuck by the v force stuffer size

I thought you plug was white? Now you're taking about it being wet? You never did say what size that hole was.

[tippmann]

Watch my post scroll down i posted v force plan and the size is wrote there
http://www.3wheelerworld.com/showthread.php/142378-My-project-Z-)

Think i have to grind the hole ?

[tippmann]

Ok just put bCk old reed cage and when i snap big gaz throttle he spit prestone So this is my head gasket right ? Or my prestone cap ?

[Mosh]

You mean prestone as Antifreeze/coolant?

Where is that "spitting" from?

[tippmann]

Coolant and by the hose that go to the coolant bottle

[Mosh]

If you are pushing fluid out the overflow line from the bottle, you either have the level in the bottle too high or you have pressure coming from somewhere..Probably the head gasket since you had problems with it sealing before. The jugs have a tendency to "mushroom" up around the studs and make an uneven sealing surface for the headgasket. You may have to pull the head and studs and flat file down the jug around the studs so the gasket will seal..So that could be your running problem.

I dont think you will be able to remove the stuffer and run the VF3 cage. The stuffer helps all that stuff hold the petals and diverter in the cage. You could proabably custom grind the stuffer, but they are pretty cheap to get the Larger one and you may need the smaller after all if your headgasket is leaking..If you call Them, he should know what stuffer you need for a larger flow that fits the V303 cage. If I recall, the larger stuffer was used on a sled motor that took the same cage as the Z.

[TimSr]

When a TriZ head gasket leaks, it always leaks the compression out through the cooling system. Each time you rev, it will shoot a little squirt out the overflow. I'm with Mosh, TriZ and bumping compression is a bad combo. You can't adjust your carb until the compression leak is corrected. Wisceo or Cometic gaskets will seal easier under imperfect conditions and might get you sealed. Use Copper Coat or some other gasket sealer made specifically for head gaskets. With cylinder shaved, its going to be hard to get compression back down.

Mosh, can a cool head help at this point, in either sealing better or reducing compression?

The stock TriZ runs awesome when properly tuned and setup, and a little bit of porting will open up the top end for super performance across the board, without sacrificing reliability, with performance exceeding what few riders are capable of using, and usually yield better end results than expensive high performance builds.

[Mosh]

When a TriZ head gasket leaks, it always leaks the compression out through the cooling system. Each time you rev, it will shoot a little squirt out the overflow. I'm with Mosh, TriZ and bumping compression is a bad combo. You can't adjust your carb until the compression leak is corrected. Wisceo or Cometic gaskets will seal easier under imperfect conditions and might get you sealed. Use Copper Coat or some other gasket sealer made specifically for head gaskets. With cylinder shaved, its going to be hard to get compression back down.

Mosh, can a cool head help at this point, in either sealing better or reducing compression?

The stock TriZ runs awesome when properly tuned and setup, and a little bit of porting will open up the top end for super performance across the board, without sacrificing reliability, with performance exceeding what few riders are capable of using, and usually yield better end results than expensive high performance builds.

Not really without mods. Those raised areas around his jug studs will still need filed down, and you have to use thread sealer on the studs even in the best conditions or coolant will wick up through the studs and leak at the head nuts. However he would be able to chamber and cut the coolhead dome for a custom fit and reduce the compression significantly. I have not experienced an compression coolant leaks with the coolheads. He already has a ton of money into this build and I would like for him to get the compression down with his stock dome if he can without shelling out big bucks for a coolhead unless he wants to buy one anyway. However cutting into his stock dome even more, will increase coolant temps as the material goes away. The coolhead would be more forgiving in that respect to cooling even after cutting the coolhead dome. They have way more coolant capacity then stock.

Tipman..I have some heavy duty thicker base gaskets here for those also. (just got some last week) I will have to double check, but one of those usually measures around .030-.040 thick uninstalled, and may end up giving you another .010 extra on squish overall installed. That may put you at .045 squish..Plus they are much stronger than the paper type base gaskets.
I can sell you one if you need it.

[TimSr]

Those raised areas around his jug studs will still need filed down


I was under the impression they lapped the top of his cylinder, in which case he wouldn't have those for the first install.

[Mosh]

I was under the impression they lapped the top of his cylinder, in which case he wouldn't have those for the first install.

Ok..My bad..Just read his other thread and they did deck the jug..So the stud areas should be clean.

Sounds like he just may have to high compression blowing out the headgasket then, or an uneven surface or defective gasket.

[tippmann]

He was not leeking while i was doin some test with
Too rich test but when i tryed some other test who was too lean he started spitting prestone
I have 180 pai compression i saw some peaple here with 200 + so probably blew it on a test to lean

[tippmann]

the funny part is after i got my cylinder and head once milled correctly i firstly assembled the top head witout liquid gasket and i got some coolant again by the same stud i was like O.O so oppened again then used some #518 lock tide gasket(red) and it made it ! but now have to open again........ + i missed a cylinder stock bore off ebay for 200 $ because my iphone internet been too slow... so i have to make this set-up work.. ill buy another full gasket set this week.. Heads gasket cost like 30 and full cost 50...

[Bryan Raffa]

what are you torquing the head too? I go 20- 22fpd never ever had to use any kind of sealant on the head,, with the steel gaskets or the fiber dirt bike gaskets.

I do not recommend using any sealer... that may be your problem! the confined space may not allow the sealant to dry, thus when it heats up,,expands,, it blows it out.

and make sure you put the head gasket in the right way there's a UP SIDE! the center ring is stepped on a oem metal gasket.

http://www.3wheelerworld.com/showthread.php/66451-proper-install-of-a-tri-z-head-gasket-for-chris?highlight=tri+head+gasket

[tippmann]

I saw that step in the metal gasket but i had no mark so i probably installed it wrong but one side or another by the gasket form i should not leak through a stud with a freshly milled head and cylinder and the gasket i usee is often user to close up leaking top end and witout any problem the gasket have to be removed with an exacto and it peel . Maybe i blew my head gasket because it was on wrong side ill tell you later this week for the next day i have some road to do to rammstein show !

[TimSr]

I do not recommend using any sealer... that may be your problem! the confined space may not allow the sealant to dry, thus when it heats up,,expands,, it blows it out.


It is possible to disagree with someone without sounding ridiculous in your attempts to demean them in asserting your "residency of expertise". Permatex Coppercoat specialty head gasket sealer does not cause head gaskets to leak, and it was once considered a standard "must use" when everything used copper head gaskets, but then I'm sure that was before your time. You shouldn't badmouth something you've never used thats been widely used throughout the automotive industry and around longer than you have, nor should you invent bogus theories of it "causing failures" in order to damage the product's reputation.


Tippeman, before you remove the headgasket, make sure you recheck the torque on it. When the metal gaskets are used they often simply need retightened once its been run and gotten hot.

[Bryan Raffa]

It is possible to disagree with someone without sounding ridiculous in your attempts to demean them in asserting your "residency of expertise". Permatex Coppercoat specialty head gasket sealer does not cause head gaskets to leak, and it was once considered a standard "must use" when everything used copper head gaskets, but then I'm sure that was before your time. You shouldn't badmouth something you've never used thats been widely used throughout the automotive industry and around longer than you have, nor should you invent bogus theories of it "causing failures" in order to damage the product's reputation.


Tippeman, before you remove the headgasket, make sure you recheck the torque on it. When the metal gaskets are used they often simply need retightened once its been run and gotten hot.

Yes..it is possible.. the Factory Manual DONT SAY NOTHING ABOUT PUTTING ANY SEALANT ON THE HEAD GASKET... SO WHY SHOULD YOU? were not dealing with copper here... and Im shure he didnt use copper sealer.. what you got some beef with me? we all know you like to use lots of permatex...:rolleyes:

oh and YES I have used it...thanks.... Go read your freakin manual... its not a old Flat head!!!!!!!!!!!!!:lol:

[TimSr]

Yes..it is possible.. the Factory Manual DONT SAY NOTHING ABOUT PUTTING ANY SEALANT ON THE HEAD GASKET... SO WHY SHOULD YOU? were not dealing with copper here... and Im shure he didnt use copper sealer.. what you got some beef with me? we all know you like to use lots of permatex...:rolleyes:

oh and YES I have used it...thanks.... Go read your freakin manual... its not a old Flat head!!!!!!!!!!!!!:lol:

The factory manual doesn't say anything about using Wiseco pistons, decking cylinders or any other aftermarket parts or 2 stroke oils either.

"Permatex" is a company name and not a product. They make several hundred products. Do you even have a clue what Coppercoat is or what its for? I don't begrudge or belittle those who don't use it or find it necessary, but I don't attempt to publically ridule them in a feeble attempt to elevate my own SUPERIOR "brilliance" either.

I do find your condescending attitude towards those who dare answer a TriZ question without your seal of approval to be offensive, especially when you do it to others with far more experience than yourself. If you want to dazzle the impressionable, do it by respectfully offering your own alternatives, and not by trying to demean and belittle those who know methods you've never experienced.

[Bryan Raffa]

The factory manual doesn't say anything about using Wiseco pistons, or any other aftermarket parts or 2 stroke oils either.

"Permatex" is a company name and not a product. They make several hundred products. Do you even have a clue what Coppercoat is or what its for? I don't begrudge or belittle those who don't use it or find it necessary, but I don't attempt to publically ridule them in a feeble attempt to elevate my own SUPERIOR "brilliance" either.

I do find your condescending attitude towards those who dare answer a TriZ questidont give fals informationon without your seal of approval to be offensive, especially when you do it to others with far more experience than yourself. If you want to dazzle the impressionable, do it by respectfully offering your own alternatives, and not by trying to demean and belittle those who know methods you've never experienced.


Don't give false information thats its ok to use permatex on a tri z head gasket... shame on you! Bad info!!! Thanks for ruining this guys post!!

[TimSr]

http://www.permatex.com/products/motorcycle/motorcycle_gasketing/motorcycle_gasket_sealants/motorcycle_Permatex_Copper_Spray_A_Gasket_Hi_Temp_ Adhesive_Sealant.htm


http://www.permatex.com/documents/tds/automotive/80697.pdf

[tippmann]

Well ill look at my head nut torque but im pretty sure gasket is blew

[tippmann]

I Borrowed a keihin 35 mm flat carb that my friend had on his banshee before he start running with only one carb. i put a 170 main jet in it and DAng !!!! too rich !!!!!!!!!!

Before testing out the carb i matched the intake with the carb size( to not choke) then matched the v-force stuffer to match the intake hole( again to not choke).

SO now with the carb test im 100% sure problem is from carb... But now the only thing in the carb that could stop me beeing more rich is the needle jet. i Presently have a 480,Q-2 with a 6fj41 needle.. Every needle jet cost 17 $ and if it dont work i cant return it.. so wich one i should try out ??? Q-6 ? Q-8 or go in the R1, R2 ??? Thx for your help...

[tippmann]

Yesterday i saw that the 6f4 needle is 62.3mm long and the 6fj41 is 68mm but anyone know if mikuni flat (tm) use same needle of the vm (round)? I know the needle jet of tm is longer that why im not sure about needle shorter. Was about to test it but the adjustement screw in the middle of the clutch broken ,,, so i have to figure out what to do with this screw