Was the vibration you had a while back related to the jug of doom?
http://www.oldminibikes.com/forum/h...ds-massive-vibration.html?highlight=vibration
http://www.oldminibikes.com/forum/h...ds-massive-vibration.html?highlight=vibration
Taking all the end play out is directly related . also that is usually caused by piston to head contact that you can not hear when its running . metal stretches when it heats and spins that's why it is crucial to check clearance on everything . do your self a favor buy a real Honda gx200 .. Predators are great on mini bikes but Hondas are proven work horses
OND, yeah, it was turning 4300 RPM at the time of failure. It had run 6200 earlier that day. I was running a billet connecting rod and billet flywheel.
Chris, yes, I think so. It must have been a hairline crank in the crank case, then spread to the point of failure.
BBQ, sorry it didn't entertain you. I've been working on the motor since Feburary, well documented on my YouTube channel. If this is the first video in the series you've watched, then it was probably boring to you. But for those who've followed the build all this time, I appreciate your condolences.
I just don't think a built 200cc-class motors can handle a marine environment well. water is 800 times as dense as air. There have been several failures on several built 200cc-class mud motors over on the Mud Motor Kit forums. Most guys are going to the 390s and 420s for daily drivers.
Bone stock it's fine, even stage 1 is fine. Once you cross the line by yanking the governor, even with all the billet parts, the little motors just don't hold up in a marine environment, especially when trying to get all that weight up on a plane.
I may just run it at idle speed like they do in southeast Asia.
Chris, yes, I think so. It must have been a hairline crank in the crank case, then spread to the point of failure.
BBQ, sorry it didn't entertain you. I've been working on the motor since Feburary, well documented on my YouTube channel. If this is the first video in the series you've watched, then it was probably boring to you. But for those who've followed the build all this time, I appreciate your condolences.
I just don't think a built 200cc-class motors can handle a marine environment well. water is 800 times as dense as air. There have been several failures on several built 200cc-class mud motors over on the Mud Motor Kit forums. Most guys are going to the 390s and 420s for daily drivers.
Bone stock it's fine, even stage 1 is fine. Once you cross the line by yanking the governor, even with all the billet parts, the little motors just don't hold up in a marine environment, especially when trying to get all that weight up on a plane.
I may just run it at idle speed like they do in southeast Asia.
Sorry to hear the hoped up motor did not work out. Using the small engines on the boat as a mud motor is great idea and being on a boat is probably one of the most demanding on a motor since it runs hard and long. I really enjoyed your videos and once again, sorry to hear about the bad luck on the new engine and please keep us posted on your new engine.
Aww man...sorry to hear that.
I enjoyed the previous videos, it's neat to see familiar motors in what appear to be new applications to us.
Even if you do go back stock, please share a video with us, so we can see it run.
Maybe we need to get you hooked up with a mini bike frame, in the event you get the urge to build another motor....:shrug:
Anyway, keep up the good work....and btw...any story to share on how you got back to the boat landing ?
I enjoyed the previous videos, it's neat to see familiar motors in what appear to be new applications to us.
Even if you do go back stock, please share a video with us, so we can see it run.
Maybe we need to get you hooked up with a mini bike frame, in the event you get the urge to build another motor....:shrug:
Anyway, keep up the good work....and btw...any story to share on how you got back to the boat landing ?
A big block is a good idea ... But I think a mild torque build on a gx200 would serve you very well . the castings are better and take way more punishment ... I am in the process of cleaning out the winter shop right now and I have more Honda stuff laying around than you can shake a stick at .. Let me know if I can help out
Thx all.
Robert, I have a policy. Never go out unless you have three forms of propulsion: the motor, oars and a paddle in my case. An old army rifle commander once told me he'd be hard on his men for playing around long tanks and such. He'd always tell them three points of contact on the tank, no dangling off the tank like Rambo.
Well, I'm done building. I've missed an entire fishing season. I'm trying to build a fishing tackle company. I've had several products that I couldn't launch this year because I couldn't get video of using it because I was wrenching on the motor. I can't tell you the number of people who have bought longtail mud motors like mine because they saw my mud motor videos.
So I gotta get back to fishing. Building takes too much time. Considering a Champion 6.5 engine since they have the good rockers.
Robert, I have a policy. Never go out unless you have three forms of propulsion: the motor, oars and a paddle in my case. An old army rifle commander once told me he'd be hard on his men for playing around long tanks and such. He'd always tell them three points of contact on the tank, no dangling off the tank like Rambo.
Well, I'm done building. I've missed an entire fishing season. I'm trying to build a fishing tackle company. I've had several products that I couldn't launch this year because I couldn't get video of using it because I was wrenching on the motor. I can't tell you the number of people who have bought longtail mud motors like mine because they saw my mud motor videos.
So I gotta get back to fishing. Building takes too much time. Considering a Champion 6.5 engine since they have the good rockers.
Always sucks to break something you have worked hard on. My first drag race after building my truck I snapped the factory crank and ruined the entire engine at half track. All the testing and tuning months before and I had it all dialed in, first race and it didn't make 1/8th of a mile lol.
When you build and play with something past it's reliable factory build something my dad taught me when I was a teen stands out. You can always have the toy but you better have something to back it up. You go out and street race on the weekend don't expect that car to get you to work on monday morning. You clearly enjoyed modding and making videos of it so don't stop. You just need to get another one so you have it to do what you have to do at work. Then play with the 2nd one and hopping it up.
When you build and play with something past it's reliable factory build something my dad taught me when I was a teen stands out. You can always have the toy but you better have something to back it up. You go out and street race on the weekend don't expect that car to get you to work on monday morning. You clearly enjoyed modding and making videos of it so don't stop. You just need to get another one so you have it to do what you have to do at work. Then play with the 2nd one and hopping it up.
So what do we think was the root cause of this failure? HP is HP, does not matter if you are turning a prop or a TAV or a sprocket. There are lots of karters out there running higher output motors than yours at full throttle for most of their races.
Do you think the case had a flaw that the higher HP caused to go south? You set the endplay to acceptable spec. Did you verify the piston deck height? Out? In? Valve to piston clearance?
There has to be a proper explanation here. HP was not the cause, only the mechanism. You have me a little worried since I am doing basically the same mods on a HEMI. Thx.
Sandor27
Do you think the case had a flaw that the higher HP caused to go south? You set the endplay to acceptable spec. Did you verify the piston deck height? Out? In? Valve to piston clearance?
There has to be a proper explanation here. HP was not the cause, only the mechanism. You have me a little worried since I am doing basically the same mods on a HEMI. Thx.
Sandor27
I think the prop it self wasn't helping. that's quite a few feet of leverage attached to the side cover, Stressing the case side to side. Not a good design IMO.
Leverage and stress of the prop/tail+ vibration issues + stress of higher hp+ a possible stress crack = boom
You stated that other 200cc long tails have had issues, what kind of failures did they experience? Case failure is an extremely uncommon issue in mini bikes and karts
Sent from my Fischer price Speak and Spell
Leverage and stress of the prop/tail+ vibration issues + stress of higher hp+ a possible stress crack = boom
You stated that other 200cc long tails have had issues, what kind of failures did they experience? Case failure is an extremely uncommon issue in mini bikes and karts
Sent from my Fischer price Speak and Spell
Sandor. Water is 800 times as dense as air. The marine environment is much tougher than races on land. Ever try running in water? It's like only running your car in first gear, with 3,000 trailer uphill all the time. That way harder on any engine. That's why all my mud motor buddies are either moving to 390cc motors or going back to stock.
Modding, The design has been a round for something like 50 years. This is what outboard motors look like in Southeast Asia. Despite what you think the design has been long proven as reliable. The drive shaft has endplay as well, and is only torqued to 10-12 lbs/ft max.
All the failure center on the modded 200cc-class motors. Again the stress in a marine environment is much harder than running mini bikes down a street or carts on a track. I've never seen a failure due to running bone stock or running higher displacement. A lot of it is user error, but the coincidence is too great.
This is a mild build on land, by put that same build in a medium 800 times as dense as air, literally flying over said medium while pushing 500 lbs total weight more hours on end at 20 mph, and lets see how long it lasts.
NOTE: if it was too much pressure on the sideplate, the side plate should have failed, not the crank case.
It's different. It's harder. It's a different animal. The same wisdom doesn't apply. Overseas they either run 'em bone stock or run the bigger block. Don't forget the water itself is supporting the weight of the longtail because the prop causes lift and takes weight off the sideplate.
Modding, The design has been a round for something like 50 years. This is what outboard motors look like in Southeast Asia. Despite what you think the design has been long proven as reliable. The drive shaft has endplay as well, and is only torqued to 10-12 lbs/ft max.
All the failure center on the modded 200cc-class motors. Again the stress in a marine environment is much harder than running mini bikes down a street or carts on a track. I've never seen a failure due to running bone stock or running higher displacement. A lot of it is user error, but the coincidence is too great.
This is a mild build on land, by put that same build in a medium 800 times as dense as air, literally flying over said medium while pushing 500 lbs total weight more hours on end at 20 mph, and lets see how long it lasts.
NOTE: if it was too much pressure on the sideplate, the side plate should have failed, not the crank case.
It's different. It's harder. It's a different animal. The same wisdom doesn't apply. Overseas they either run 'em bone stock or run the bigger block. Don't forget the water itself is supporting the weight of the longtail because the prop causes lift and takes weight off the sideplate.
Just my opinion bwl .. I have built a number of these engines . the clone castings are exactly what they are called Honda copies . the castings are not made to the specs a Honda is . they are more pourus cheaper material . and if building one to take abuse you need to support the block . but your failure is 80 times out of 100 caused by piston to head contact . when meatal heats and spins 6000 plus rpms for extended periods it will stretch . so in essence what you have going on is piston contact with the head surface that you can not hear when it is running and you pushed the jug off at its weakest point . run a Honda on a power tamp for years and watch it perform flawlessly try that with a clone motor and watch it fail after a very short period