Today a guy I know asked if I could help him do a engine swap on his 250cc trailboss with a 500cc honda streetbike engine. He wanted me to help because I have all the tools and a welder. I agreed to do it if he gave me the old 250cc engine. He agreed to do it. So first he brough over the 500cc honda bike and we striped it down and got the engine and electrical out of it. just as we got done, his brother brought the polaris 250cc quad AND a 50cc Impuls quad that I had done some trading to get from him. So the we cleaned up all the bike parts laying around and Dove into the polaris. Some time later as we were getting ready to pull the engine, I realised that it had a seperate tranny on it. He said well, I can sell that and make some money. without hesitation, I said that the engine is not any good without the tranny. he didn't say anything... 4 hours later, we sat the 500cc honda in the polaris 250 trailboss chassy to size it up.. the upper frame had to be choped to get it in. and I am going to have to move some of the cross members to get it to sit lower on the chassy. I am also going to have to weld tabs on the uper frame that we chopped out so that I can bolt it back on. As of right now. the top of the 500cc honda is sitting about 4" above the TOP of where the uper frame used to be. I am going to have to do some fabrication to it to make it all go back togather and make the seat and the tank all line up.

So now I have a polaris engine and trannyout of that deal, and a TXL 50cc quad. I thought using the 50cc suspention and rear axel to make a go cart frame and then putting the 250cc engine on it. I don't think all the work will be that big of a deal after using a shoehorn to get a 500cc 4 cylinder in a 250 polaris trailboss chassy. What do you guys think I should do with the engine/tranny and the 50cc quad?

I will post pictured as soon as I have some that I can scan into my computer.

 

*update*
After about 4 days work on the trailboss, and much frustration. It was done to my lack of satasfaction. They wanted to just make everything work not thinking about the future. I should not have expected anything more. They ghetto rigged everything they could just to make it work. They didn't care about doing it right at all. And now I am ashamed that I let my name be put on it. I sat down on it to start tracing out the wiring and make a wiring harness. That was not good enough for them. They jumped in front of me and found 12 volts and jumped it strait to the coils. And then wondered why the keyswitch and starter didn't work. Then they just let all the rest of the wiring harness just lay there occasionally sparking and shorting while they were working. before that, it was even better, they cut out the old 250 swing arm mounts and then welded in 3/4" water pipe segments to put the swingarm pivot bolt through. And to cure the slop they created, they welded the swing arm in solid to make shure the chain would not come off. I almost stoped the whole project right there. But I wanted the 250cc drive train real bad, so I bit my tounge. I am a welder/electrician by trade. I would have thought that they would have let me do that part right. Their idea of motor mounts was bolt a scrap of metal to the engine and then hammer it over to the chassis and weld it on. First time welders mind you. It is now sitting in their yard awating new points that they blew out. I have a feeling that that is where this so called quad will spend all of its time.... in their yard, under a tarp. I got a wild hair today and decided to put them all to shame. I decided to put the 250cc engine and tranny on the 50cc eton that I just recently got. I just got started today. Right now, all I am doing is removing & bagging & tagging all the parts like steering, brakes, and a arms. They came over and asked me why I was doing all of that and said it was going to take too long to build it. I just grinned at them... they have no clue.... they are kids... while they were there, I started to cut out the old motor mounts and misc tabs on the frame and grind them smooth. While I was doing that, I was informed that I was just wasting my grinding disk. Once again, I said nothing. and just grinned. They hung out for a while and kept wondering what and why I was doing all of this. I just kept smilling.. Soon they decided to leave after what I was doing got boring to them. As they were ready to leave, I asked are you going to be ready to race me in about a month?

I have to complete this project to redeme my good name to everyone who knows about "their" so called quad. I feel so ashamed that I even let them touch my mig welder. I will not ever allow anyone to do that to me again.... unless I am getting something like a ninja 600 engine or better out of the deal...

 

one other update....
I extended the eton50's swing arm about 8" to prevent the 250 from pulling wheelies. I hope that this will be enough.

from my guestimate, I should still be able to pull a wheelie, but not unless I want to with this setup. Now I am wondering about the off road preformance of it when it is complete. Will in still hug the corners with a extended swing arm? And will it want to bottom out when I land while doing jumps?

 

you can't wait till the race,you will be both necktoneck,suddenly here comes the hill, you both become air,you both return to earth, you whole and moving out,you look over to see, not to your amazement dillweed in multiple sections with his stupidly welded (+badly done) rear swing arm beating the s*#t out of his stupid hairdo,rolling off to haities. i did not like my mushy bike so i put bushings in the springs,now it lands straight+firm,but the tighter you go the more likely it can throw you off on a landing.so you have to hold on tight.

 

I didn't think about that... now I have to bet him $$$ and make shure that the race has some good hills and jumps in it....
he will be bouncing around all over the place with the swing arm welded on solid. That is "if" all his welds hold togather. ha ha ha
ha ha ha

update on his gettofied so called quad...
he burnt up the points in the 500cc honda engine and now he seem to be moving to another location.... I cant find him to talk to him about it. I might try to buy the quad and see if I can pull the motor and use it in a gocart. All he is going to do is drive it on the street until he get caught by the cops and gets it impounded.

update on my polaris 250cc project...
I tried and tried... I could not get the engine and tranny in the 50cc chassis so now to plan "B".

I am laying everthing out to make a go cart with the eton 50cc front a arm suspention and rear axel, my homebrew swing arm, and the polaris 250 engine and tranny... I also have all 4 working brake hubs and pads. that will be nice to have both front and rear brakes on a go cart that has that big 250cc engine. Does anyone know what the hp rating is for a 1997 polaris trailboss 250cc?

the problems that I am running into is all the room that the engine and tranny will need. so I am thinking about mounting the tranny on the swing arm with the drive sprocket inline with the spocket on the axel and then mounting the engine above the axel and behind the tranny.

unless anyone tells me why I shouldn't, I am planning on using 3/4" or 1" water/gas pipe from the local home depot. It is galvanized but it is cheap and easy to weld and pretty stong

If I am correct. with the belt drive clutch and the foward and reverse on the tranny, I would have to run the tranny in reverse to make this work but my theory is that it should work because the gear ratios are the same in foward and reverse.

another problem that I am having is that the belt that came off of the polaris drive train is real short. So the engine and tranny have to be so close the the carb is litterally sitting on top of the tranny... I don't like that from a fabricators point of view. It makes it real hard to make motor mounts precisly. And then everything is in the way when you try to tighten or loosen the motor mount bolts.

<div class="FTQUOTE"><begin quote>Originally posted by: MECHANIKE

you can't wait till the race,you will be both necktoneck,suddenly here comes the hill, you both become air,you both return to earth, you whole and moving out,you look over to see, not to your amazement dillweed in multiple sections with his stupidly welded (+badly done) rear swing arm beating the s*#t out of his stupid hairdo,rolling off to haities. i did not like my mushy bike so i put bushings in the springs,now it lands straight+firm,but the tighter you go the more likely it can throw you off on a landing.so you have to hold on tight.</end quote></div>