150cc T-rex Daytona motor - photos

[HACKMUNCH]

no but we had to use the kevlars that came with the 4v dohc kit with the 4v or it slips.

 

[grnman]

i just saw last night at a shop that you can get 4mm offset pins for the crank giving a stroke increase of 8mm!
so if you used this and the 60mm piston kit, you could make a vegas killer motor with specs of -
60mm x 66.7mm = 188.5cc DOHC.

 

[sean01]

finding a short enough conrod to suit may be a pain in the a$$

 

[grnman]

you just run a big a$$ base plate.

 

[sean01]

barrel studs?
cam chain?

 

[grnman]

cam chain is easy, you just put two chains together, and studs are easy to make with a lathe as well. my motor currently has all this stuff on it.
oh and you need a bigger cam chain tensioner

 

[Barnesd09]

Just to stir the pot a bit more.....
I decided to pull the covers off the YX and I found some disturbing tolerances with regard to the main shaft and clutch. Also found how oil feed lines don't line up, no bearings or washers on gears.
No wonder these engines shake themselves to pieces after a few race meets [riding motard]
So after working on both the Daytona 125 and 150E I can see where the money goes and how for the same capacity it will make a touch more power as there aren't things iside restricting movement of moving parts and extra care is taken to get tighter tolerances to eliminate play.
A Daytona will be my next engine, I just hope the YX holds up till the end of the season.

 

[pbk]

Just to stir the pot a bit more.....
I decided to pull the covers off the YX and I found some disturbing tolerances with regard to the main shaft and clutch. Also found how oil feed lines don't line up, no bearings or washers on gears.

do you have any pictures of these??

also do you have a yx160 or a 155z?

also what do you mean by no bearings on gears?

i also find it hard to believe that there arent any washers between gears...

 

[Barnesd09]

I have a YX160 and a Daytona 125.
I didn't take any pics as I was in a rush to get it all back together ready to be shipped to go racing in Hobart on Sat.
When the bikes get back I'll take a few pics and point out the parts I'm tal;king about and show a comparison.
There are washers between gears but not on all of them, the second kick gear and between the cluch basket and the main shaft gears, no washer, just a gap of about 1 - 2 mm, but the Daytona have all of these covered.

 

[wogtaz ryder]

i just come across this somehow ... mite mean something i duno

http://www.miniriders.com.au/tech-talk/29322-daytona-125-engine-help-urgent.html

 

[HACKMUNCH]

according to our "glee club" in utah (pitster) the daytona 150 and the $265 z155ho are the same LOL. BELIEVE THAT AND ILL SELL YA A BRIDGE IN FLORDIA.

 

[Chrisc161076]

When will the kits be ready to buy off the shelf? Really interested in the +R setup.

 

[wogtaz ryder]

You can already buy the +R's but there made for a difference engine , so you gotta do abit of tweaking . and i heard there not much more flash then stock . for the price anyway.

 

[Chrisc161076]

You can already buy the +R's but there made for a difference engine , so you gotta do abit of tweaking . and i heard there not much more flash then stock . for the price anyway.

What tweaks are required? Are they making one especially for the Daytona?

 

[grnman]

No they are not. from my understanding you need to put a smaller cam chain in as the port heights are different on the +R's.

and im with Woggy, there is no way the +R is worth the money for the very minimal performance gain.

What kit do you want to buy anyway. all the parts you need you can already buy. ill buy the parts put them in one box and sell them to you for a premium.

what setup are u wanting to get?

 

[Chrisc161076]

I'm not in a massive hurry to get this sorted as l got this bike late on in the season, which has only got two races remaining...

From what l hear Daytona have developed a new clutch basket with different rubbers, which actually lasts, so l would like one of those and l want more power and speed but with reliability, so l was thinking of a fully skirted bbk and 160 stroker crank and doing it all at once.

I would go DOHC but l don't want to be consistantly carrying out maintenance, l want something l can practice on, ride with my mates and use the same engine to race with aswell.

 

[grnman]

Ok well this doesnt sound like a straight forward job at all. if you are going to run a 2mm stroker and 60mm bore then your going to have grave issues with the compression its running. Number one the 2mm stroker will raise your compression to 14:1 and then making that into a 60mm bore your compression will be around 15.75:1.

you will then like me have to make a base plate of maybe 3mm+. then because the deck height has changed you will need to make a longer cam chain to reach and modify the cam chain tensioner and guide wheel as well. so now that your total head height is taller you will then have to make longer studs or like i have done counter sink the head nuts into the head and use the stock studs.

i have just taken delivery of the DOHC head and am amazed with its quality. i dont see how the maintenance on these heads would be anything different from the 2v. because the it is DOHC, you have the ability to adjust both the inlet and exhaust timing advances. this means that you could tone down the power and create heaps of torque at low revs for practice riding so the maintenance intervals are less frequent.

 

[Chrisc161076]

I would prefere the dohc kit, l don't mind doing the oil, filter and checking tappets, the easy quick stuff lol

Do you know anyone with the dohc and how long it has lasted, or how long the bottom end has held up?

 

[grnman]

ummm i dont personally. but im sure Hackmunch could tell you. the 150 DOHC kit comes with the new wisco piston instead of the old piston in the 119cc kit that didnt last long at all.

you could run the DOHC kit and put the 2mm stroker in it without changing anything major. that would mean you dont have to make any base plates or cam chains and would simply drop on the top after the stroker has been fitted.

and run your ignition on stage 1 for practice to give your bottom end more life.

 

[HACKMUNCH]

its been awhile, sorry. well our 4v dohc has been through it's paces.(running for 6months) just won a few races recently. no real major issues and maintance is down to the bare minimium (changing oil). we have not shimmed the valves since day 1 and the clearance is still in spec range. the engine has just recently been stroked to 160 (with daytona stroker crank). deck heigth is the exact same so it's just a plug and play gig. the engine has been started and heat cycled but not "real" ridden yet with the stroker. the dohc kits are on sale here in the US for like $1499 this month. IMO thats the way to go but we have another guy on the team that races the 167cc +r daytona and claims to be making the same power as the 150 dohc engine. time will tell. hope this helps