Hi all just restored my ct3 175 and its up and riding ok.....it just doesnt seem powerful enough it gets up to 40 to 50 on flat ground reasonably but seems to struggle on hills i get about 30mph i dont know if i have an unreasonable expection has i ride a 961 commando so i dont want to investigate and strip for no reason ...im about 13 stone ...does anyone have one to compare has ive said its running fine ...carbs been cleaned..good fuel..new filter etc barry.

Hello Barrya, your CT3 should be able to go faster than 40 to 50mph on flat ground even though you weigh 13 stone (182lb). I have been riding a CT3 for many years and I weigh 150 to 155lb. Before I modified my CT3 and with stock gears on flat ground my CT would get up to near 65mph, although I could not hold that speed without the engine getting too hot. It would easily maintain 55 to near 60mph with no problem. On hills the speed can be a slower depending on the incline of the hill and the weight of the rider. Concerning your CT3, I would recheck the timing using a digital gage to make certain that the points open when the piston is 1.8mm BTDC. Also, if the carb is too rich this will affect speed, check the jetting.
 I use a heat gauge on my CT and I would recommend others to do the same especially when playing with the jetting. Do not let engine temperature exceed 430 degrees Fahrenheit. The top of the piston will have a hole in it at around 500 degrees F. (ask me how I know that! )

I'm right at 182 lbs and my CT-1 cruises at 55 easily on level roads, and can get to 60+ MPH, using GPS to measure speed. I've found that my speedo reads about 4 mph high. I went up one tooth on the countershaft sprocket, which may actually reduce top speed (it won't rev out in 5th gear), but it feels better on roads.

Just took it out i can get 50 to 55mph flat out on flat but it seems abit sluggish and tach does not go past 5....the airscrew on the carb is 2 full turns out has per factory settings does any one know any different...the jet is 200 ...im in the uk ...thanks barry.

Will it rev past 5K RPM in the lower gears? Is your air cleaner clean and not restricting?

I'm permanently stuck in Exhaust Mode when it comes to performance.
Plus what everyone else said of course.
Ok, found this of my 125 with a 175 top end. Admittedly a TY175 cylinder but they're not a high performance cylinder.
Head is our farm model AG175 early model so effectively just a CT2 head.

I'll link the page so as not to block up your post with my rat bike crap videos. Second video is the one i mean to show riding it albeit with clutch slip which slightly improved.
Just to show it revs freely. Has super high gearing with a cotton reel rear sprocket.
First vid by memory was fitting a dreaded chinese carb, which i got jetted good but we won't talk chinese carbs-will we lol. It becomes like an oil thread.
Right at the very start of the vid if you stop it playing you can see the rear sprocket looking across. Might be more visible on the carb video. I know ya all sick of my videos haha. Hence linking rather than live.
yamaha-enduros.com/index.php/forums/1968...-chinese-carb-on-175
yamaha-enduros.com/index.php/forums/1968...h-is-slipping#149026

Speaking of EXHAUST, have you removed the end pieces of your muffler to make sure it is not plugged up with carbon?

As TomP.  My 175MX is geared up one tooth for road use and has almost identical performance.  Cruise at 50mph with ease on the flat in still air.  Will slowly arrive at 55mph and 5500rpm and hang there.
If I go down a gear I can hit 60mph with the engine at full throttle, but it sounds nasty.

I weigh in excess of 200lbs and have ex bodybuilders shoulders.  The engine has to use a lot of power just overcoming the drag of my parachute like body.
A slim, lightweight and small statured rider would get considerably more performance from it.

Gearing up a tooth from 14T std to 15T has killed the top speed, but is better for the road.  Are you using std gearing?

My brand new one seemed like a fire breathing monster back in the day (weight 140lbs max and like a beanpole), but as road bikes went, I was climbing the stepladder of performance from my Fizzy (4bhp), through to a Honda TL125 (8.5bhp) to the DT (15bhp).

Coming back down from Honda CB1300s and CBR1100xx Super Blackbirds (165bhp) to my VFR750 (102bhp) and then slinging a leg over my now DT does not set my hair on fire.  I suspect you are in the same boat.

Remember, these bikes were never designed for outright top speed, they were designed to have tractable, easy power both on road and in the woods.
My 2stroke road bikes. The coffin tanked Yam RD200 and 250 had very big steps in the powerband at the top end at the expense of lower rpm performance, to boost top speed.  It was like flicking switch.  Hardly any power to full power in 1500rpm.
The DT does not have this.  The power is linear from 3000 rpm up and I suspect the top of the torque curve is around 5000rpm.

Aircleaner is brand new...and does not seem to want to rev out past 5 in any gear thanks barry

Is the air cleaner stock or a pod? I had a pod filter and had a problem revving over 5k. it turned out that the opening was restricted with a step down from the outer part of the boot. I got another pod with a full size opening, and it runs well now. In fact I just went for a ride and in every gear I can rev up close to the red line, except in 5th it takes a while to get to 6K.+.