1988 honda elite sb50p engine swap

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

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iampee
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1988 honda elite sb50p engine swap

Post by iampee »

hi everyone i have a 1988 Honda elite sb50p and have finally came to realize the unfortunate lack of upgrades with the non variated engine. i have put a new exhaust on it and it runs and sounds great but is still a bit disappointing speed wise. im not too concerned about top speed but mostly torque and acceleration from a stand still. i have done a lot of research and it seems like my only option at this point is an engine swap. my question is: will any af16, af18 engine work? seems a bit too good to be true to have everything line up. im okay with making holes bigger and dealing with wiring but im mainly concerned about the mount alignment. thanks!
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Re: 1988 honda elite sb50p engine swap

Post by Meatball »

Any Af16-18 will fit with some minor modifications. The wiring is a simple swap of the main plug underneath. The shock mount to the frame would need to be moved slightly unless you use a long shock and dont mind sitting higher. Fuel and vac lines need to be a bit longer and so does the rear brake line. The motor mount from the Af16-18 needs to be used and slight modification is needed to fit into the sb50 frame.

Besides that, it slaps right in! You will have some space issues fitting the fatter motor under the skinny body plastics. This can be handled by trimming plastics for the exhaust on one side and running a pod air filter on the other. You also might need to trim the mudflap since the rear tire will rub.
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Re: 1988 honda elite sb50p engine swap

Post by bonesv »

Yea what Meatball said, or, maybe you could just buy an Elite SA50 that has the AF16 already on it and go from there? I know someone selling one in Florida (not cheap) but it's complete w/title. Where are you located?
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

awesome thanks so much for the info meatball! <3 i have been considering getting a whole new scooter but i just found an af18 engine thats a bit steep but still cheaper than a whole new scoot. so i think im going to go with that. im located in co.
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Re: 1988 honda elite sb50p engine swap

Post by bonesv »

iampee wrote: Tue Oct 07, 2025 12:09 pm awesome thanks so much for the info meatball! <3 i have been considering getting a whole new scooter but i just found an af18 engine thats a bit steep but still cheaper than a whole new scoot. so i think im going to go with that. im located in co.
Hey man, that's cool! I know that there's plenty of guys that have built AF18/16's and crammed them into a small frame like the spree or SB50 with no problems. It is not that difficult but I do hope you use good parts, methods and make safety first as you may be faced with costly challenges.
I had so much fun building a couple of scooters the way I thought I wanted them and had excellent results! Best wishes to you and have a blast with it! Bones :thumbwink:
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

yeah i love how small the sb50 is. im able to lift it in the back of my van by myself! hopefully the swap goes smooth. thanks for the info!
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Re: 1988 honda elite sb50p engine swap

Post by bonesv »

iampee wrote: Tue Oct 07, 2025 5:43 pm yeah i love how small the sb50 is. im able to lift it in the back of my van by myself! hopefully the swap goes smooth. thanks for the info!
Hey, it's like Meatball said, you have to reinforce the frame and in a few places also, and the other is you have to make up a motor mount bracket from one of the other scooters that fits best and make it true(even and straight)and strong enough that you can trust it to ride down the highway with it. :2thumbs:
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

just got the new engine in. unfortunately it looks like im going to need a new engine mount as the one that came on the engine cant be shaved down enough to fit in the frame:( looking like i will need to buy a lot more to get this going
Last edited by iampee on Wed Oct 15, 2025 4:12 pm, edited 1 time in total.
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

also wheel doesn't fit. at this point i might as well just build a whole new scooter 😭
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Re: 1988 honda elite sb50p engine swap

Post by Meatball »

Many people have done this exact swap over the years. Its a cool Colorado winter project to tinker with. Easy completed by giving it an hour or two here and there over the snowy Winter months. Its not you’ll be riding much with the roads iced over anyways.
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

since i need new wheel set can i just swap the back? or will it be too big and ill need to swap front and set up disk break and possibly new fork?
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Re: 1988 honda elite sb50p engine swap

Post by ntonar »

Its a fun swap, I love the size of the SB50
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Re: 1988 honda elite sb50p engine swap

Post by Meatball »

All you need is a new rear wheel. You can even use the tire and tube from the sb50 wheel since its the same size.

You can leave the front alone and run the stock stuff up there for now. The stock af18 will have great acceleration, hill climbing power and a top speed of about 40mph. Once you start modifying the af18 with big bore kits and all sorts of goodies, it can go 60-70mph with the right combo. Then you would want to do a full disc setup in the front for safety reasons.
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Re: 1988 honda elite sb50p engine swap

Post by iampee »

that thing is beautiful! i need me one of those tail lights 🤤. i will post some pics of mine soon but i cant figure it out on my phone.

and thanks again for the info meatball! great to know. will start keeping an eye out for a rear rim.

my current list of parts for the swap is:
engine mount, got one just need to make it fit the frame
exhaust
carb and filter
rear break line
maybe a shock
and not sure if i need new throttle cable
and now a rear wheel
not sure when ill get around to this but very psyched to get this thing rippin even harder! thanks again everyone for the help! <3
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Re: 1988 honda elite sb50p engine swap

Post by bonesv »

iampee wrote: Wed Oct 22, 2025 5:53 pm I will post some pics of mine soon but i cant figure it out on my phone.

thanks again everyone for the help!
You must resize them to 600k or less or it will not accept it. Either an app or photoshop, etc. will work.
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