buiding a TAG 131 ?

hbk31

New member
I have a Parilla 125cc MY09 Lepord TAG engine, can it be stroked and turned into a 131cc engine? Has anyone ever Built one as an open? Thanks Darrell Hotler
 

animal 77

New member
i'm sure it can, just send the crankshaft to the crank works in phoenix az. and they can stroke it for you. you will need to make a spacer to move the reed cage away from the rod because of the extra stroke, and move the cylinder up with a spacer for port timing, and buller dual carbs. will help :) and change the pipe to a cre-9..... I have 2 engines that use the older leopard stroked crankshafts with ignition halves on both sides. the taper is different then a regular parilla so if you change the ignition to pvl or selettra, and use a hegar belt driver they will need to be machined for a proper fit because the tapers are different. ( they are on my engines anyway )
 

hbk31

New member
Was curious if i could leave it as a TAG with the starter and run it on a Jackshaft. I havent heard of or seen to many open TAG engines. I think I still Have a stock Sudam crank I could have welded and redrilled that way i can use my belt drivers I have.
 

animal 77

New member
on your sudam crank be sure it's the newer style with 90* angles on the crank throws ( or counter weights as I call it ) and not the older style with the tapered edge.. it should work.
 

rainman

Premium User
Just wondering what is the gain from going from 125 to 131, other than other changes. Is it worth it at all? JMO
 

MikeGrady

Member
You don't weld the crankpin and offset grind it. You have it relocated outward 3mm. Remember, this rod doesn't come apart. You take the crank apart to install the rod. Send the crank off and have it done right....or you will wish you had.
Mike
 

animal 77

New member
You don't weld the crankpin and offset grind it. You have it relocated outward 3mm. Remember, this rod doesn't come apart. You take the crank apart to install the rod. Send the crank off and have it done right....or you will wish you had.
Mike
x 2 :)............
 
Just wondering what is the gain from going from 125 to 131, other than other changes. Is it worth it at all? JMO

There is a lot to it but it creates an advantage with the port timing by adding stroke and added torque. Yes it is well worth the cost of stroking. I have been told that a Sudam will make more power by stroking it rather than boring it big to a 57mm, but stroking it and boring it will make more power.jmo
 

arc100

Member
I'm told the std electric starter that hangs off a TAG is pretty useless once you modify the engine into an open.
 

Freezeman

Premium User
I have not been in the Leopard Tag cases. Does it have a water passage under the crank area? The rotax does and a stock rod only has about .012 clearance to the ID of the flywheel case opening. Even a 1.5mm move south of the cranks pin hole to achieve a 3mm stroker would mean the case crank hole would have to be opened up in the center for the big end clearance which would run into the case bolts and possibly through the wall of the water passage. IDK about the leopard but I would suggest that if your looking at stroking the crank I would also be looking real hard at how that extra stroke is going to fit into the cases too.

I have seen that the starter that hangs off the stock Leopard Tag becomes useless quite often too.
 

azrcr

New member
Having built quite a few opens based on the leopard, I found it's sub pare to other options.. the starter will not start a alky open leopard., the crank halfs are marginal, as the stock ignition is not a total loss system and will need the powerpack., it also has a 2port exhaust (in the tag class, it's allowed a lower weight due to its lack of power) than more current 3port tag engines..

With that being said, before the soniks came out and were economical, I built all of mine on a iame lowerend (stud relocation required) using a sonik or, tt25 crank, I've also built them on a prd, and sonik lowerend, (stud relocation required)., however if your going to use sonik stuff, why even use a leopard? We have soniks out to 131,140, and 148cc's.. the case's of the soniks due not have wet jackets in the case, the center of case's have to be relieved for the rod, and a reed spacer is required, I use a old reed cage and machine off the reed part, just leaving the flat part, the spigot hole also has to be enlarged on a iame case..

It's been awhile, but if I remember right, the leopard has a 100mm rod, and with the extra stroke the piston will shank out on the crank at bdc, so the skirts will have to be trimmed, (being cautious not to free port the engine..) you also have to trim spigot hole ledges or piston will shank out on them.. you will also need a spacer plate for bottom of cylinder., building a hybrid open is seldom just a bolt together project, count on machine work., measure and plan it out..

And I disagree about stroking being better than a bigbore, and it is a easier than building a stroker, I have crank works here in Phoenix do all my cranks, I can't do it for what they charge,.

Alot of the tag class tracks have a leopard only class so they still hold some value alot of times more expensive than a Sonik or prd, vortex, which are better engines., I can pick them up for 4-600.00, if you can do the work yourself, you can build a 131 or bigger open for less than 1000.00 or so. (not counting, carbs, pipe, etc.)

With the leopard, to get the power, be prepared to do some major porting due to the 2 port exhaust, it's limited in the stock configuration., Abetter option would be just start with a more current 3 port engine and get more power stock., basically a open leopard is going to be a money pit..

One thing I will add, i've built a quite a few prd opens, the rods (much like a kt rod), I was a little worried, but i've had no failures with the rod.. they are cheaper than a iame rod and stand up to the the open mods..

The soniks, prd's, vortex's run a selletra or pvl, or the prd use's its own ignition, they are total loss systems, current kart type ignitions..
 

RadialFin

New member
azrcr do you have any videos of those motors you've made? I'd love to hear em.
In terms of porting the Vortex has a good setup too.
 

azrcr

New member
no videos or pics.. I mentioned the vortex, they are a 3 port and do make a good open.. I've done several of them also..
 

azrcr

New member
No prob. with all the tag class's in euro, going to the kf engines several years ago., we are once again seeing good old (and cheaper) engines for open builds, we always get the euro hand me downs.. there's nothing wrong with a air cooled sudam, and they will be around for years, but the newer wet engines have the same porting plus the advantage of being wet engines, same power but will maintain a lower temp over a race, meaning you can tune a faster engine.. Al and Jason have been having mixed results with the new kf engines..

Good luck finding a used sudam cylinder, the only option is to buy a buller cylinder or resleeve yours.. it's just a matter of how you want to spend your money.. I still own several sudams, (these are keepers, a stock and 131).. with low bores, but for 131 and up engines I'll build on a sonik base, great case's, cranks, cylinders...
 

hbk31

New member
Having built quite a few opens based on the leopard, I found it's sub pare to other options.. the starter will not start a alky open leopard., the crank halfs are marginal, as the stock ignition is not a total loss system and will need the powerpack., it also has a 2port exhaust (in the tag class, it's allowed a lower weight due to its lack of power) than more current 3port tag engines..

With that being said, before the soniks came out and were economical, I built all of mine on a iame lowerend (stud relocation required) using a sonik or, tt25 crank, I've also built them on a prd, and sonik lowerend, (stud relocation required)., however if your going to use sonik stuff, why even use a leopard? We have soniks out to 131,140, and 148cc's.. the case's of the soniks due not have wet jackets in the case, the center of case's have to be relieved for the rod, and a reed spacer is required, I use a old reed cage and machine off the reed part, just leaving the flat part, the spigot hole also has to be enlarged on a iame case..

It's been awhile, but if I remember right, the leopard has a 100mm rod, and with the extra stroke the piston will shank out on the crank at bdc, so the skirts will have to be trimmed, (being cautious not to free port the engine..) you also have to trim spigot hole ledges or piston will shank out on them.. you will also need a spacer plate for bottom of cylinder., building a hybrid open is seldom just a bolt together project, count on machine work., measure and plan it out..

And I disagree about stroking being better than a bigbore, and it is a easier than building a stroker, I have crank works here in Phoenix do all my cranks, I can't do it for what they charge,.

Alot of the tag class tracks have a leopard only class so they still hold some value alot of times more expensive than a Sonik or prd, vortex, which are better engines., I can pick them up for 4-600.00, if you can do the work yourself, you can build a 131 or bigger open for less than 1000.00 or so. (not counting, carbs, pipe, etc.)

With the leopard, to get the power, be prepared to do some major porting due to the 2 port exhaust, it's limited in the stock configuration., Abetter option would be just start with a more current 3 port engine and get more power stock., basically a open leopard is going to be a money pit..

One thing I will add, i've built a quite a few prd opens, the rods (much like a kt rod), I was a little worried, but i've had no failures with the rod.. they are cheaper than a iame rod and stand up to the the open mods..

The soniks, prd's, vortex's run a selletra or pvl, or the prd use's its own ignition, they are total loss systems, current kart type ignitions..

Thanks for the info Mike. I Have the Leopard sitting around and was curious if it was worth building as an open.
 

azrcr

New member
I guess it depends on how much money you have, and access to machines.. I'd guess it would cost 6-1000.00 to have it built..
 
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