Hey, I have been building for a bit now, some may have seen pics of my newest build I just posted on the cruiser forum. But I have always built cruisers and always used grubee gt5's. But now I think I want to build a mountain bike for trail riding. My question is, does a 4 stroke offer better low end power? I know nothing about 4 stroke motors. I was looking at the 49cc from deamon bikes. Aside from reliability and not mixing your oil, what benefits does a 4 stroke offer? Can I expect more power or speed from a 49cc 4stroker? also what does anyone think about fitting this thing to a bike? AUTO 125CC 4-STROKE ENGINE MOTOR ATV GO KART DIRT BIKE - eBay (item 150565213084 end time Feb-28-11 02:13:27 PST)
best low end power
- Thread starter walander
- Start date
The answer will always be generalizations, but... in general.... a 4 stroke will be heavier & generate less hp but more torque for a given capacity & rpm. So yes, low end can be better than 2 stroke. 4 stroke reliability is a myth, there are more moving parts so there is more that can go wrong. rings, pistons & cylinders do sometimes last longer as the rpm is often lower.
Four strokes have much more low speed torque and less hp (as mentioned above) but for trail riding a geared down 2 stroke would be lighter.
The engine in your link lacks a carb and would need a battery and wiring plus exhaust system. Suitable for an experienced fabricator/ mechanic.
By the way- there is no way a 2 stroke will last as long without re-building, as a 4 stroke will last.
The power strokes are double and the heat created is doubled.
One plus with the smoker is they are very easy to re-fresh.
The engine in your link lacks a carb and would need a battery and wiring plus exhaust system. Suitable for an experienced fabricator/ mechanic.
By the way- there is no way a 2 stroke will last as long without re-building, as a 4 stroke will last.
The power strokes are double and the heat created is doubled.
One plus with the smoker is they are very easy to re-fresh.
the fact that the 4 stroke says it's top speed is 35 mph is laughable to be honest, it sucks up more fuel has nearly 2-3x the displacement and wont give you any more power then our little chinese 2 stroke kits?
if their numbers are accurate thats a gigantic waste.
if their numbers are accurate thats a gigantic waste.
There have been a few guys who showed up on our monthly So-Cal club rides with 4-stroke engines; (some bragging how fast they were.) 
They have always ended up at the back of the pack once we got rollin'!
IMHO, if you want good low end power for trail riding?, a fully ported HT with a giant rear sprocket will make you very happy!
They have always ended up at the back of the pack once we got rollin'!
IMHO, if you want good low end power for trail riding?, a fully ported HT with a giant rear sprocket will make you very happy!
Last edited:
