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2 Stroke Bicycle Engines & Kits 2 stroke motorized bicycle engine kits need careful installation and setup, find out how from our professionals here!


The Kamakazi - My "second" build

2 stroke motorized bicycle engine kits need careful installation and setup, find out how from our professionals here!


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  #21  
Old 05-10-2013, 09:26 AM
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Default Re: The Kamakazi - My "second" build

So I have not been having very good luck with my engine lately. She was purring along fine so I decided to add back on my SBP expansion chamber. She got the expected pickup but also started running hotter. Over the last few weeks I have been trying to resolve the heat issue trying different jet sizes and generally fiddling with it. But it seemed she kept on losing power. I have only taken short rides while trying to solve the heat issue (1-2 miles per run). I even ordered a new Speed carb since I had mixed the parts between the NT and the Speed carb and couldn't figure out what parts belonged where. But even the new carb didn't resolve the issue. So I pulled the SBP pipe and had even LESS power. I pulled the piston and saw that my piston was burned. The cylinder is still in great shape no scoring or burning and the rings do not appear to be broken or damaged. I have been running a 32:1 mix on my third gallon through so still enough oil. Not sure why the piston is getting toasty or what to do to get the missing power back. Like I said I have fiddled with the jets and am pretty much back to stock. Also have a brand new NGK B8HS plug (was having good luck with it with the SBP pipe on). Any ideas would be great, thanks!
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  #22  
Old 05-11-2013, 08:37 PM
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Default Re: The Kamakazi - My "second" build

Hey I got a good joke for y'all, let me know if you have hear this one. So a guy gets this bike motor that is supposed to be the bee's knees and he is kind of new to the hobby. He THINKS that he has a high quality motor, but after about 300-400 miles the piston bushing starts disintegrating! So now he is left with bike motor that he really can't do anything with because we all know that you cant put a bearing where a bushing goes (something about the metal not being hardened to handle the stress)!!!
Oh wait, that was me. Yeah...and, well, number two engine, the one I BABIED and TRIED to make sure it was broken in and ran well JUST did the same farking thing!!!
Please forgive me for ranting but either the engines I have gotten are total crap or I am a horrible mechanic (or both). I am just about ready to give up! I have spent more time FIXING this POS then riding it! And I am tired of it. I have the motor I cobbled together from my first motor that the bushings blew and the third that blew the bearings and for right now it runs ok. But honestly I think if that one dies without at least a couple thousand miles on it, I am quitting the hobby.
God, I am married with a wife and three kids, I can't afford to throw away my messily fun money to find a good engine. And frankly with the my luck on these, I may not!
I admire the **** outta you guys that make this look so easy and can turn these HTs into decent machines. I thought I could do it, but I am not so sure anymore. My frustration level has gotten to the point where I am making sloppy mistakes that could contribute to the failures too.
Perhaps it's time to pour my pennies into getting that street bike that I wanted in the first place. I am sure I would be almost 1/4 there if I hadn't gotten a bike motor.
And please, do me favor, don't tell me that I should have gotten a four stroke or a magical CDI or I should have done this or that. Thank you.

Rant mode: off
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  #23  
Old 05-11-2013, 09:33 PM
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Default Re: The Kamakazi - My "second" build

I'd suggest another engine. I've seen them for under $100 bucks on fleabay.
The newer motors seem to be better quality lately.
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Old 05-12-2013, 03:52 PM
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Default Re: The Kamakazi - My "second" build

Good Afternoon. I have a theory about my engine failures, an angle I had never thought about until now and I would like an opinion from one of the expert mechanics around here.

From my first engine I have been running Homelite 2 stroke oil that you find at Home Depot and thought nothing about it. But looking through the forums I found a fact that I should have realized from the beginning.
HOMELITE IS A SYNTHETIC OIL. All the pistons from the engines I have pulled have been burned.
Could it be that the rings never properly seated due to the oil? I know there a few ideas that running synthetic doesn't allow the rings to seal correctly. Could this be it? God to think that I messed these up with a stupid oil?
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Old 05-12-2013, 09:45 PM
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Default Re: The Kamakazi - My "second" build

Risingsunn- Hello! I've been reading along, and man I think it's time to ask 'Norm's Two Stroke Repair'. I can't offer you any information, but that fella will certainly be able to.
Your missing out on the fun my friend! Less fixin- more ridin Hang in there, and keep us updated.
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  #26  
Old 05-18-2013, 08:02 PM
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Default Re: The Kamakazi - My "second" build

Quote:
Originally Posted by Risingsunn View Post
Good Afternoon. I have a theory about my engine failures, an angle I had never thought about until now and I would like an opinion from one of the expert mechanics around here.

From my first engine I have been running Homelite 2 stroke oil that you find at Home Depot and thought nothing about it. But looking through the forums I found a fact that I should have realized from the beginning.
HOMELITE IS A SYNTHETIC OIL. All the pistons from the engines I have pulled have been burned.
Could it be that the rings never properly seated due to the oil? I know there a few ideas that running synthetic doesn't allow the rings to seal correctly. Could this be it? God to think that I messed these up with a stupid oil?
I have had problems with what I thought was "not being able to find the right carb jet" in the past. My engine ran hot and sounded like it was four stroking. It lost power at high RPM. I messed with the thing until I was disgusted with it. Finally, I ditched the stock head and got a Fred Head from CR Machine. I switched to premium unleaded, and used a cooler spark plug. This cleared up my problem and it runs great now. I believe my problems were caused by detonation. Also, I know a lot of people will say not to use synthetic oil for break in, but I used Amsoil Saber, (which is full synthetic) for break in with no problems. Did it on my first build, and it is still going strong at 3,000 miles. Did it on my current build, and no problems with it either. To each his own, I hope you get it sorted out. I hate to see someone give up and not experience the fun of this hobby. All the best to you and yours. -J
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