Got some in action pics from a while back. On the home pc

 

Defiantly one of the nicest TTR125s I've seen

 

Very nice, I need to do something with mine

 

Thanks guys it's still a work in progress. May have to bump up the spring rates in the forks or stiffen up the valving some more it's kind of a trial and error. Still need to shave the flywheel of some weight. Overall its still fun to go play around but I just want a little more out of her. Debating after she's done buying an x5 to be a little more serious with

 

you wouldnt by chance have the stock 2001 rear spokes you would like to sell? I broke half of the spoke out of mine and i dont really want to play 50 bucks to get new spokes.

 

No I actually got rid of my stock spokes when I changed rims as they won't work for me anymore.

have a new vid of me playing on the ttr starts at about 4 minutes

 

some action pice i promised

 

Long time no post. Just had the motor torn apart again for a broken counter shaft. So now im adding a few little upgrades to it.
Bought an electric start harness, bottom end with bad crank, e start motor ect, basically everything to make the bike electric start since kick starting it i killing counter shafts and kicker gears.
Also added, Adult bend bars, bar risers, BBR shfter, YZ80 carb, uni pod filter, tall seat foam, gripper cover, Added a LE aluminum swingarm probably missing a few things but it is what it is. slowly ticking off everything i want in this bike. next step is making the motor crazy! just need the $$

Bike prior to this tear down and after replacing counter shaft Painted the frame black as well

Heres what the last counter shaft left as carnage as well

Internals of both motors

Bottom end assembled

Waiting on a fe more part to come in and ill have it filly assembled

 

So got the motor all rebuilt. Still burning alot of oil even with new seals and a good ring gap. Thinking may just be time for an overbore. It may just be time to to build a 4valve motor I think I've researched enough now to go for it.

A few tips for those of you that want to convert to e start. And are too stubborn like myself to just buy a bike that already has it.

Make sure if you buy a used harness it comes with all of the safety switches and the ignition key. Otherwise you will have some homework to do to bypass them or spending a lot of $$ on all the sensors.

You only need the left side case from a e start model
Your stock front motor mount will need to be trimmed to clear the starter.
You will have to weld on the battery box mounts as they won't be on your frame. (This may not be true on 03 and newer models my 01 did not have them)
Otherwise it's really simple

Does anyone have any other ideas on why I may Still be burning oil like crazy? Rings are properly aligned, new valve seals. New gaskets. All Dowell pins in place. Compression is low and timing is correct so I am suspecting worn cylinder. Piston has low hours with brand new rings.

Stay tuned I may just say screw it and go for the 145cc motor with 4valve head

 

I vote screw it, get the 4 valve.

 

I am doing a TTR125 build and I would be curious how you get a 4 valve head to fit/ which model head it would be! great thread so far

 

I don't want to say for sure that the head fits but I bought a Zuma 125 head. There is 2 places that currently sell a 4valve kit for the raptor 125 which is the identical motor to the ttr125.
Firepower minis when I emailed them their price was $800 stock bore
Precision Motorworx they have a variety of stuff. Aluminum sleeve kit 13:1 piston kit. And the 4 valve head.
I picked a head based off of the photos they have and searched Yamaha 125 head and compaired pictures. Well see if I got it right. So far the gaskets line up. Still a lot more homework to do. I think Firepower minis is spot on on their price. I'll get a parts list and price list going once I figure it out.

PMW does amazing work though and have tested it like crazy in gncc racing. They are on top of their game.

This won't be a direct bolt on mainly because I have not found a 4valve piston the right size to stay stock. So we shall see what happens. I'll keep everyone updated.

 

Definately keep us updated on how that 4 valve head turns out and the cost for it. I have thought up building up a ttr125/yz85 "big mini" because my friend well sell me his complete bone stock ttr125 for $200 so I could build it for cheap, but the lack of motor mods is what has kept me from doing this project. (Before reading this thread I thought the only mods available were the BBR 150cc bore kit and cam which doesn't seem to make that much of an improvement from the reviews I have read). A 4 valve head plus the bbr 150cc bore kit could have some potential...

 

Well I ordered what I believe should be the parts needed for the 4 valve build. Along with extras as well. I'm sure there will be more things to be done. Just don't imagine this being a bolt and go job. I'm sure there will be some machine work involved. Will continue updating as thing arrive. Crossing my fingers this all works.

 

So got a email today piston rings are backordered till Feb so I guess a few weeks delay on top of regular shipping times

 

Ok everyone here is my current parts list and price, please keep in mind i have ordered many extra parts that may not be needed i can update this as discover what may have to be changed and what actually needs to be used from this list.

RC Racing

65mm Forged Piston $110

EBAY
Yamaha Zuma 125 Big bore cylinder head kit 61-66mm Bore with cam $240 Ebay also available on jiangwayne This head will not fit 58.5mm Bores valves will hit cylinder!

Billet rocker Arm Cover for Zuma 125 $40

Billet Cam Breather Cover for Zuma 125 $28

Tusk Full Gasket Kit TTR125 $28

Zuma 125 Cam chain $25

OEM Parts

BOLT, STUD 1 (5ML-E1391-00-00)	4​	7.96
Sprocket Cam Chain (5HH-11549-10-00)	1	34.17
Crank Bearing (93306-205YX-00) (Stock TTR Could use originals i decided to replace)	2	28.47
ARM, VALVE ROCKER (1P3-E2151-00-00)	1​	24.64
ARM, VALVE ROCKER (1P3-E2161-00-00)	1​	23.51
SCREW, VALVE ADJUS (5FM-E2159-00-00)	4​	7.96
NUT (90170-05800-00)	4​	4.08
SHAFT, ROCKER 2 (5HK-E2156-00-00) (Stock TTR Shafts are identical)	2​	7.98
PLATE (5ML-E111F-00-00) (Stock TTR cam Plate is identical)	1​	1.99

Racing Planet USA

Naraku Adjustable Camshaft Timing Gear $37

Local Shop (standard Price List)

Lightened flywheel $50
Press Sleeve in Cylinder $50-100
Bore Engine Cases $50 (does not include splitting cases)

Current Total $1034
this price can be lower but it reflects the parts I chose. Because Big minis are fun haha! there are definatly was i could have saved some cash!

I have no clue what else ill have in store or if this will even work

 

Way cool project!!! Dood (a member here) told me he did one years ago using a Taiwan issue Yamaha 130cc scooter head. He had to make a new manifold, oil intake passages and a custom piston if I remember right. I think it produced 17 hp. Keep us posted!???

 

I know for sure the bolt pattern and timing chain cutouts fit I had bought a base gasket prior to doing this and it matches perfect. Oil passeges seem to match as well. We will see the head and billet made it into customs last night so hopefully it will arrive next week. I'll at least get to mock it up against the stock cylinder and see if I need to order a different timing chain. I rememeber seeing a post from Dood that he ad done it but no details with it. I hope I can build it and hopefully we can get the ttr125 back onto the mod scene

 

I hope this works!

 

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

 

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.

 

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.

 

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

 

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

 

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....

 

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