[greenducky55]

So good new Head and billet parts have cleared customs no delivery date determined yet.
Big bore kit is still on back order due to rings out of stock till feb. If anyone else is attempting this right now the 63mm Kits are in stock.

Got my kill switch installed no key set up on my bike. It works like a charm. Hope this E-start saves my kicker gear/countershaft

So a few weeks back i made a mistake and ordered a 2 valve older model 58.5mm Big bore kit bright side i was able to use it for some research. If i ever wanted to build a 2 valve motor i believe i could use this setup as well only paid $60 for it so no big deal haha. I am hoping the gaskets and ect are the same on my other cylinder. but we will see.

Cylinder and piston

TTR base gasket on that cylinder you can see the cam chain passage is different

Zuma base gasket on TTR bottom end. Oil passage blocked. This is why i plan to use the TTR cylinder with the Zuma Sleeve

 

[greenducky55]

Here is the base gaskets on top of each other for reference

Head gaskets of each stacked

Have much more research to do as in check where the zuma cylinder head gets oil.
also all of my oem parts came in this week as well

Edit: looks like it goes up the same way as our motors so no worries on the how the head receives its oil.

 

[greenducky55]

Well head was supposed to be here yesterday. Since I was at work I couldn't receive it needed a signature. So now have to wait for Monday to pick it up from the post office. Oh well till Monday.

 

[YZ250F4ever]

I am doing a TTR build as you know and I am really enjoying your build.

 

[greenducky55]

Alright Picked up the goodies today. Did some mock up work. Well here is some pics and plenty of words haha!
Bottom of the head should

Head with the billet covers on. (cam cover needed to be flipped was way to excited haha)

Intake side (going to need a custom intake manifold our stock one is not near to fitting the bolt holes are too narrow

Exhaust side: fits my BBR header perfect

Cam (its a cam dont know how the profile will perform we will see can always have webcam do a custom if I need to)

To be continued in a few minutes lol

 

[greenducky55]

Assebly of the head was a total pain in the rear. but i know some trick now that make it alot easier.
1. Install the cam, valves, springs, retainers, keepers first
2. the exhaust rocker is a super right fit, you have to push it up and past its install location and then place in its location its way too tight to do straight in ( i don't know if this would be true on a stock zuma head.
3. i had to debur a few things there are some rough casting spots (china quality control) all of the machined spots fit great

Intake side no covers

Exhaust side no covers

TTR cam sprocket on bottom Zuma sprocket on top (same teeth count different diameter)

zuma head gasket on its own head valves are super close on this gasket. its a 58.5mm head gasket and the head is spec for 61mm + bores we will see how it looks when my piston and rings come in. (they shipped out today from china)

TBC....

 

[greenducky55]

TTR head gasket on zuma head (for comparison)
This is where some welding and machine work is gong to be needed more details on my plans on next pictures

zuma head gasket on ttr cylinder
Plans are to weld on more material to the outside of the block where the cam chain would slide through ( will make more sense when i get it done

Head bolted to ttr motor for mock up purposes. ended up only using the shorter cylinder studs from the zuma and the stock ttr alen head bolts ( ill update the parts list today)

TTR head in front of zuma for height comparison

this is how short the ttr cam chain is so going to order a zuma cam chain and then if that doesn't work ill order a custom on from tsubaki

to be continued

 

[greenducky55]

Engine mounted in TTR frame (had to cut off the upper motor mounts off of the frame otherwise intake valve cover hits) ** may not be true if you use stock covers**

SO exhaust bolted to the head perfect but came up a little short on the stock frame mounting hole (could make a little bracket to offset but ill probably just cut and weld a new one to the frame)

And now for some quick mock up with the plastics on if you used the stock covers it wouldn't even gain any attention from a non ttr owner (but where is the fun in that!!!)

 

[greenducky55]

so that's it for now wait for a few more parts and then off to all the machine work! looks like this should work like a charm

 

[old skool]

Really looking good!!

 

[YZ250F4ever]

all i have to say is WOW!

 

[greenducky55]

So after sitting on the bike and playing with the rebound I think I'm going to have to set a faster rebound with the adjustment at its fastest it just seems too slow. I'm going to double check my sag set it and see. But as of right now I think I gotta rework it oh well bike isn't going anywhere right now anyway. I guess. Might as well buy the Race tech bladder cap too it's only $35.
Thanks everyone this thing is hopefully going to be a beast. I'm really hoping I don't have to order a custom piston and sleeve. Things will increase quick if so. If it comes to that I may just order a piston and nikasil sleeve from pmw and go from there.

 

[crazybentley]

Looking forward to hearing how the engine runs with the 4 valve head!!. I have always wanted to build a ttr125/yz85 conversion build, but the lack of motor mods available always kept me from doing it. Hopefully this 4 valve head will put out some good power.

Those spokes/rims looks awesome by the way. Any reason why you didn't do the full yz85 swingarm/linkage/shock/rear wheel/rear disc brake conversion? Also I have heard the newer style ttr125 plastics bolt right up to the older bikes, and they look way better IMO, might want to check it out. Either way this build is looking good!!

 

[greenducky55]

Thank you lmkinda love this little thing!

Hoping to have good power gains as well. A company they currently mods to make the 4 valve conversion claims around 17hp with a 150.
Newer ttr plastics are $700 brand new and they aren't easy to come by you need the tank and the seat as well as the old style won't fit sop too much $$ for cosmetics.
I didn't go for the yz rear set up because the geometry is a guessing game. Not saying some of the guys here have not done a great job I really think they have. But regaurdless to fit an adult rider you have to 're spring and re valve the suspension so might as well save myself the work and run the ttr suspension modified. And the rear hubs can last if your not bottoming out all the time. I only have about $500 in my suspension and it's worked pretty flawless (not sure about my shock reworking yet)
And I can stop perfectly fine with the rear drum I honestly do not use the brakes a lot on this bad boy at the big motocross tracks momentum is everything just like a 125 2 stroke so I like my setup it's not for everyone but I push it to its limits and I'm happy.

That was a lot of blabbering sorry haha

 

[crazybentley]

Thank you lmkinda love this little thing!

Hoping to have good power gains as well. A company they currently mods to make the 4 valve conversion claims around 17hp with a 150.
Newer ttr plastics are $700 brand new and they aren't easy to come by you need the tank and the seat as well as the old style won't fit sop too much $$ for cosmetics.
I didn't go for the yz rear set up because the geometry is a guessing game. Not saying some of the guys here have not done a great job I really think they have. But regaurdless to fit an adult rider you have to 're spring and re valve the suspension so might as well save myself the work and run the ttr suspension modified. And the rear hubs can last if your not bottoming out all the time. I only have about $500 in my suspension and it's worked pretty flawless (not sure about my shock reworking yet)
And I can stop perfectly fine with the rear drum I honestly do not use the brakes a lot on this bad boy at the big motocross tracks momentum is everything just like a 125 2 stroke so I like my setup it's not for everyone but I push it to its limits and I'm happy.

That was a lot of blabbering sorry haha

I understand what your saying. For a playbike like this, I don't think having a rear drum brake is that bad. And I heard that the newer LE model rear shocks with remote resi can be rebuilt/revalved with some sucess. But I was under the impression that one of the main reasons for upgrading the entire rear end to yz85 stuff is to lift the rear of the bike to match the ride height in the front due to the longer yz85 forks. Did you drill a new shock mounting hole to raise the rear end of the bike? Or did you just slide the forks up in the clamps and just ride it as it?

 

[greenducky55]

I ended up just redrilling the hole. Took my time to measure and try to keep the angle the same but ended up with a softer ride than before hence the re valve and ect.

 

[greenducky55]

So a few of my parts came in this week.
Billet timing plugs/oil fill plug (so glad to have a hex head to remove instead of the flat type that strip easily)

Longer timing chain (hopefully long enough)

Lightened flywheel (Oh it is sexy really anxious to see this and the counterbalancer combined)

Exhaust studs (probably should have ordered them a little longer but they work great. Super easy to install)
No pic

Well that's it for now still waiting for piston and rings.... Next time I'll check stock before I order from them.

 

[greenducky55]

Lord this thing is beautiful. In scared of what this is going to cost. PMW is making a billet cylinder with nikasil coating and water cooling ports! Not sure how he plans to run the plumbing electric water pump maybe?? Not sure still crazy idea. And no modifications. Required for the 4v head. Pushing the limits of the little 125. I have seriously no connection to these guys other than drooling over their work just incase anyone was wondering.

 

[greenducky55]

Well did some more homework on setting up my 4valve head. And things I'm going to have to purchase or modify. Going to see if PMW can't help me out on one of my issues.

My 100link timing chain is way too long so going to have to break and rivet the master link which I anticipated.

The Zuma cam sprocket is useless for the most part. It is for a different size chain than the crank so yeah.
TTR chain on Zuma TTR and TTR

The ttr sprocket fits physically in the space provided in the head.

The ttr sprocket does not fit the Zuma cam. The Inside diameter and the key are too big. So either I venture into a custom sprocket which I am imagining won't be a cheap option and really more work than I was hoping for. I'm going to pull my ttr cam and compare it to the ttr cam.

Problem with the ttr cam possibly is the profile won't be ideal for the 4 valve head. If this is the case I am hoping PMW can shed some light on it and hopefully he has a cam ready to go for this issue.

Last bit of bad news the ##@$ rings are still on backorder.

But this got me looking into ordering a 63 or 65mm piston and custom sleeve from la sleeve. They actually have a sleeve on their shelf that may fit perfectly just needs to be cut to length. So we will see. This project is a lot of work. But someone had to do the homework for the diy crowd haha.

Stay tuned!! Next week I may light it on fire!

 

[greenducky55]

Alright had a nice little research week with the motor. i think i may have finally figured out how to make it all work together.
I will not lie my homework was to stare at someone else's pictures of their hard work of making it happen.
At this point i am definatly thinking the $1500 price tag that the two companies are charging is justified haha.

By the way I added pics to my previous post to show a few of the things I was talking about. anyways to the Meat of this post!

Compaired cams today... wont be swapping them haha
2 valve on the left 4 valve on the right

2 valve 58.5 mm piston left and Weisco Hi comp stock bore on the right. happy to know the pin heights are the same so i wont have to stress about a custom pston hopefully.

Computer is forcing me to restart i will follow up in a few (stupid widows 8)