• We are no longer supporting TapaTalk as a mobile app for our sites. The TapaTalk App has many issues with speed on our server as well as security holes that leave us vulnerable to attacks and spammers.

Phazer engine reliability ?

It amazes me that we are surprised these motors are running 10,000 km. The filter change is at 20,000. I ride motorcycle's in the summer months and can get 100K out of a bike motor. I expect these motors to run 50K without issue.
 

I've seen Phazer MTX's who were used as a snowmobile safari machines. Sold with 30000 km on the ODO. That's almost 20000 miles :) and not any engine problems reported


Skickat från min iPhone med Tapatalk
 
But why not 100,000 kms? I'm currently riding a 2014 Honda NC750X that currently has 15,000 kms and I know that motor will take me beyond 100,000 kms easily. So why not the phazer motor?
 
2007 Phazer I just purchased has a new engine and both clutches were replaced at 1,400 miles from previous owner.....crank end or gear reduction broke off, took out both clutches.
 
Gotta go to work early but I'll leave a quick shim. I think the Phazer has potential to get quite good mileage. The stepbrother - YZ 250 the dirtbike engine has problems with piston longetivity. However the Phazer has longer piston skirt which prolongs piston life and cylinder life. But the Phazer engine is quite more extreme than your 750 bike when it comes to things like piston skirts, cylinder pressure etc. NOS-Pro, your problem with the crank sounds similar to the Rotax 800 engines. The reason for them breaking down is jumping and big rev differences when landing. The thing is the 2-strokes with their pressed crank. Big mass in movement and image stress will move with the drivetrain. From track to driver to chain to clutches and belt to gear reduction to crank. On the Rotaxes it's really common that the crank twists a few degrees, that gives unbalance and the weakest link is the greased filled crank bearing. I guess that since we have cast crank, as in one unit it can't really twist, but the cracks sounds like something that can happen because of that force. But I cannot say, it can be a manufacturing error also :)

A lot of people have bad to say about drive belt instead of chain drive. And yeah, the belt breaks if someone sets a jump with to high rev and to much throttle but instead - better to blow that belt instead of twisting the crank? Manufacturing thinking at its finest, there is a reason for weaker clutches on cars. Better to slip the clutch than blow the gearbox, diffs or driveshafts. Much cheaper fix :)
 
Last edited:
Semifreak said:
Gotta go to work early but I'll leave a quick shim. I think the Phazer has potential to get quite good mileage. The stepbrother - YZ 250 the dirtbike engine has problems with piston longetivity. However the Phazer has longer piston skirt which prolongs piston life and cylinder life. But the Phazer engine is quite more extreme than your 750 bike when it comes to things like piston skirts, cylinder pressure etc. NOS-Pro, your problem with the crank sounds similar to the Rotax 800 engines. The reason for them breaking down is jumping and big rev differences when landing. The thing is the 2-strokes with their pressed crank. Big mass in movement and image stress will move with the drivetrain. From track to driver to chain to clutches and belt to gear reduction to crank. On the Rotaxes it's really common that the crank twists a few degrees, that gives unbalance and the weakest link is the greased filled crank bearing. I guess that since we have cast crank, as in one unit it can't really twist, but the cracks sounds like something that can happen because of that force. But I cannot say, it can be a manufacturing error also :)

A lot of people have bad to say about drive belt instead of chain drive. And yeah, the belt breaks if someone sets a jump with to high rev and to much throttle but instead - better to blow that belt instead of twisting the crank? Manufacturing thinking at its finest, there is a reason for weaker clutches on cars. Better to slip the clutch than blow the gearbox, diffs or driveshafts. Much cheaper fix :)
Click to expand...

I think your right.....could have been, who knows how it was ridden. It happened to the previous owner and happy to see it's running strong :)
 
Nice to hear, I don't think you need to worry too much about that happening again. Especially since you seem very aware when it comes to driving and the mechanical behavior. And that really have a positive impact on longevity of the machines :) But if it happens to anyone, it will be interesting to hear about it and if the ride style is to blame. But it never is, is it? ;)
 
Just look at the engine disassembly sticky. Its obvious some of the gear reductions were made with too tight tolerance gear to gear=heat and failure. Even Yamaha is not perfect. Our little Phazer motors are turning 9-12000 rpm almost all the time. No streetbike engine unless raced is doing that for most of its life. Heat cycles also add up. So just time takes a toll on metal strength. That 20000 mi mark is where I will be going into the engine and putting that head on whether something has failed or not. When that time comes I will be replacing any suspect parts such as pistons and valves without a doubt and frankly not think twice about it since at 14000mi and 8 years my Phazer has already outlasted two or three normal sleds!
 
Voda2000 said:
Impressive. Did he do a top end or still the original pistons and rings?
Click to expand...

That the strange thing. The sled was running perfect at 10,000 miles but he thought he should throw a set of pistons in it. Compression was perfect. He installed some Wisco pistons and less than 500 miles a ring turned and caught a port. He rebuilt it with arctic cat pistons and ran it another 2,000 and sold it. If he hadn't played with it, it would have gone the full mileage without a wrench to it.
 
I have seen plenty 10000+ mi cat 2strokes. Also seen plenty go down with bad gas at 300mi. They are good engines just cant count on gas. So 4st 4 me!
 
Yup, I had the exact same sled as my buddy's and mine blew up three times. Lean condition at high speed. I'm done with 2 stroke sleds.
 
Last edited:
You must log in or register to reply here.


Back
Top