Dratv Hyper 88 Kit

Miniac

Member
:confused: oook let me ask this then,will my factory motor with the 88cc hyper kit perform like a 110cc lifan?

Actually, one of the little kids on the pit bikes out at the trails I ride at RIPS on a CRF50 that his old man claims is an 88. It has an FMF pipe and a bigger carb, and I suspect a high rev cam and some porting, but he spanks the 90-110 crowd. The 140s can out run him, but not by a lot. He is a good little rider, and it's clear that his dad has tied up some money in the little bike, but it is still really impressive. I know I'm the guy that said, "There's no replacement for displacement" but done right, an 88 kit will really perform. Maybe it's the shorter stroke on the 88 letting it rev to the moon, . . . I don't know.

If you want to just bolt it in and go, the 110 might be the easiest choice, but if you like to tinker the 88 might just surprise you, . . . and the folks that ride with you.

-kevin
 

Miniac

Member
ok i have a quick question, I know I've asked this before but nobody has given me a clean answer:

If I were to buy the basic 88cc kit from dratv (link below) can I run it on my stock CT70 engine without having to buy a new cam, carb, etc?
...
-roguenine1138 :yellow70:

Yes and no. (How's that for a straight answer?!?)

You can install an 88 kit all by itself. You may need to play with carb jetting a little bit, but once that's dialed you're in good shape. However, the stock carb is pretty small and the stock ait filter and exhaust are pretty restrictive, so they will be the limiting factor at higher RPMs. The 88 kit by itself, set up right, will give you more kick at lower RPMs , but for the full benefit to be realized you'll probably need a little more carb and a little less restriction in the exhaust and intake. The only 88 kit that I personally installed included a 20mm carb and a Uni filter and the owner also bought a new FMF exhaust. When we got done with it I was pretty impressed. With the stock cam and the subtle increase in carb and exhaust, it still had a nice mild power delivery, but the power was deceiving, cuz it would run off and leave stock 70s.

If you want to do it in stages (88 kit this month, big exhaust next month, bigger carb the month after that) you'll spend more time dialing (and re-dialing) things in, but it's not an unreasonable approach if you are a tinkerer.

-kevin
 

roguenine1138

New Member
hey thanx! that really did answer my question. lol. after reading your info i think its best if I do it in stages. thanx again for taking the time to break it down for me =]

:yellow70:
 

swanni06

Member
The one I posted above comes with a race cam and a bigger carb,so all I would need is a better free flowing exhaust?
I am kindda worried about my motor though,I was running it hard today and it was blowing alot of oil out of the crances tube,what does that mean?
 

Miniac

Member
The one I posted above comes with a race cam and a bigger carb,so all I would need is a better free flowing exhaust?
I am kindda worried about my motor though,I was running it hard today and it was blowing alot of oil out of the crances tube,what does that mean?

Usually that means your rings are shot and the most common causes of rapid ring wear are poor air filters and overheating. The overheating part is why the high volume oil pump and a good oil cooler are so important on these little beasts when they are pushed to the limit and beyond.

swanni, . . . have you been thrashing your little CT engine? :D

-kevin
 

swanni06

Member
Usually that means your rings are shot and the most common causes of rapid ring wear are poor air filters and overheating. The overheating part is why the high volume oil pump and a good oil cooler are so important on these little beasts when they are pushed to the limit and beyond.

swanni, . . . have you been thrashing your little CT engine? :D

-kevin
lol maaaybe I just got it a week ago ..it has been running wierd so to get it to run good I have to thrash it,also if you kick the kickstart to fast it doesn`t turn the motor over.Sounds like a 110cc or 125cc lifan is in my future.
 

Miniac

Member
lol maaaybe I just got it a week ago ..it has been running wierd so to get it to run good I have to thrash it,also if you kick the kickstart to fast it doesn`t turn the motor over.Sounds like a 110cc or 125cc lifan is in my future.

The slipping kickstarter thing isn't too uncommon. Often a clutch adjustment will fix it. As far as the blow-by goes, you might want to install a valve cap with a breather on it before you decide your engine is shot, . . . . unless you are looking for a good excuse to buy a big engine. That works, too. ;)

-kevin
 

racerx

Administrator
Staff member
Administrator
What do excessive blowby, poor running and a slipping clutch all have in common? If an engine has all three simultaneously, it's worn out and in need of a rebuild.

An 88cc kit isn't going to match the output of a 110-125cc motor unless the setup is fully optimized into a high-rpm screamer. Some riders really love this type of engine and working through the gears. That displacement will never match the torque output of the larger engine, that's where there truly is no replacement for displacement. Horsepower equals mph, torque equals acceleration. Road and race uses have different requirements.

You could add a stroker crank to the mix and transform an 88cc kit into 110cc. By that point (fully optimized system) your bottom line wouldn't be impacted substantially. The CT70 lower end is a solid base for 110cc and, 60mph+ would come pretty easily. On the other hand, if your goal is cheap, big displacement, power then the lowest initial cost will be a Chinese motor.
 

swanni06

Member
Thats what I thought,I believe I will go the chinese route just to get it running,then build the honda motor up after in my spare time .I just have the "I wanna get this thing out on the street and ride" fever lol
 

Miniac

Member
Well, you can never have too many engines. (Just don't ask my wife about that. She's rather uninformed in that department!) Let's see, . . . I'm up to 7 that aren't currently installed in a bike, . . . and one of them will actually run! I do have 5 chassis in various staste of assembly that are waiting for the engines, tho'. Does that count for anything?

It's a disease, and I'm terminal.

-kevin
 
Top