scotto-
Custom 4-Stroke Bike Builder
You unhooked the governor.....you did not remove it completely from the inside of the crankcase? That could well be your problem as the internals need to be removed as well as the linkage on the outside of the engine.
On a very serious note here, the angle of the head tube and forks concerns me!
That is an awful lot of rake there and can be hazardous in handling the bike at speeds greater than 25mph. With the kind of power that engine produces the front end can come off the ground easily (wheelie) and a few hard landings could snap the front end off. This would be a horrible way to get hurt or worse.
I'm in no way picking on your build, just very concerned about your safety here. I know first hand what 212cc engines with their weight and power are capable of.....please trust me here.
On a very serious note here, the angle of the head tube and forks concerns me!
That is an awful lot of rake there and can be hazardous in handling the bike at speeds greater than 25mph. With the kind of power that engine produces the front end can come off the ground easily (wheelie) and a few hard landings could snap the front end off. This would be a horrible way to get hurt or worse.
I'm in no way picking on your build, just very concerned about your safety here. I know first hand what 212cc engines with their weight and power are capable of.....please trust me here.
Yeah, i see what you are saying, thanks for the input. the problem is that the frame i made is steel abut the forks and the linkage part is aluminum, so i was going o welt a U-bold to the steal and use lock nuts on the U-bolts(3 of them). or is there any other way to set it up ...... that was actually my concern as well
KCvale
Well-Known Member
Listen to the man Bunny, the man knows of what he speaks, that is an extremely hazardous frame for any motor.
professor
New Member
I use a 212 and kept the governor.
The gov can be tweaked a bit to bring the revs up.
The stock 212 makes max power at 4400 rpm, right at the limit of the gov tweak. My engine is stock except for a .033" drilled main jet and free flow exhaust (long and quiet), makes just over 9 hp.
Great motor but vibes like wild.
One benefit of using the gov (besides not having to do anything inside the engine (and never being able to blow it up by over revving- to say nothing of a flywheel exploding and taking out some of your body parts).
The gov senses load and compensates for it.
Are you sure you have a 12 to one or so ratio?
Mark the tire and the clutch then count how many revs the clutch bell has to make to rotate the tire one rev.
I see very little reduction in ratio ahead of your back sprocket in your pic.
Maybe I missed it.
If you are geared more like 4 to one- the engine will be so overloaded that 20 something mph is all it can manage and the clutch will eventually fry.
The solution is a bigger driven sprocket on the jackshaft from the engine and / or a smaller one driving the chain to the rear end.
The gov can be tweaked a bit to bring the revs up.
The stock 212 makes max power at 4400 rpm, right at the limit of the gov tweak. My engine is stock except for a .033" drilled main jet and free flow exhaust (long and quiet), makes just over 9 hp.
Great motor but vibes like wild.
One benefit of using the gov (besides not having to do anything inside the engine (and never being able to blow it up by over revving- to say nothing of a flywheel exploding and taking out some of your body parts).
The gov senses load and compensates for it.
Are you sure you have a 12 to one or so ratio?
Mark the tire and the clutch then count how many revs the clutch bell has to make to rotate the tire one rev.
I see very little reduction in ratio ahead of your back sprocket in your pic.
Maybe I missed it.
If you are geared more like 4 to one- the engine will be so overloaded that 20 something mph is all it can manage and the clutch will eventually fry.
The solution is a bigger driven sprocket on the jackshaft from the engine and / or a smaller one driving the chain to the rear end.
MEASURE TWICE
Well-Known Member
The 1st two sprockets look to be about equal, so 1:1. The others may be what I hear is 44/12 = 3.7 Then 1 * 3.7 = 3.7 or 3.7:1 ratio. If those are 24 or 26 inch wheels that is high ratio. Engine is powerful so it could go, but the clutch would suffer.
If the from 2 sprocket are maybe 8 and 13 teeth then 13/8 * 44/12 = 6
6:1 ratio
I once had 8:1 ratio with 26 wheel with 3hp 4 stroke and clutch heated so I has to up it. I probably did not need go as low as 20:1 ratio, but I am needing up hill off road trail climbing torque. My top speed it around 15mph.
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Just read it again, you get barely 25mph. 25mph is going and so let me correct myself, the clutch may be holding or slipping some, but it could also be the engine is chugging due to maybe the ratio being to low, ie high gearing. 6:1 ratio would be around 50 mph if 26 inch wheel theoretically.
Does the clutch slip and heat?
MT
If the from 2 sprocket are maybe 8 and 13 teeth then 13/8 * 44/12 = 6
6:1 ratio
I once had 8:1 ratio with 26 wheel with 3hp 4 stroke and clutch heated so I has to up it. I probably did not need go as low as 20:1 ratio, but I am needing up hill off road trail climbing torque. My top speed it around 15mph.
============
Just read it again, you get barely 25mph. 25mph is going and so let me correct myself, the clutch may be holding or slipping some, but it could also be the engine is chugging due to maybe the ratio being to low, ie high gearing. 6:1 ratio would be around 50 mph if 26 inch wheel theoretically.
Does the clutch slip and heat?
MT
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RicksRides
Member
the rake and trail are bit excessive ride careful