Spree bbk tuning help

[Provost33]

Well this is my first moped upgrade. Im new to this so i could always use some help. Bought a 85 Honda Spree yesterday. runs great. I did a little researching and notice that changing the motor would be the best performance upgrade but I decided to go with the 48mm bore kit from tazland001 on ebay. I also ordered some Michelin starcross 2.75-10 tires. plan on cleaning up some of the chrome and plastics a little. Thanks.. i throw some pics on because i know everyone likes pic

[Pineapplegti]

I see no moped... I only see a scooter.

[martynkim]

I see no moped... I only see a scooter.

50cc small and not a motorcycle = moped to a noob. You know what he meant.

[goreyboggs]

Nice bike! Hard to find with the petcock cover.

[Provost33]

ok... Iv got some pics i will post later but iv got the bbk in and waiting on the 21mm carb. I put the bigger main jet (i believe its a 90) and i wanted to run it a little at idle and little throttle while im waiting for the carb. when it first started up it sounded great.. ran it for a little and shut if off.. then today i added some oil to gas just for break in. So now it starts up but is very boggy and smokey.. I drained all the gas because i remember doing this to one of my dirt bikes before and if you dont mix the oil around it will drop right down to the carb. so i drained the oil and the bowl on the carb... now it will start up and sound great for about 20 sec then start to bog again.. everytime i drain the bowl it will run good for the 20 sec.. Plug looks good in color but pretty wet. I think im getting to much fuel but I dont know why all of a sudden that would happen. If anyone can throw me a bone that would be nice... on second thought now that i think about it, i did mess with some other screws trying to find the main jet. i pulled some out on the side and put them back in all the way... I know what one is the idle but other then that im not sure if i have another on in all the way when its an adjustment

[Provost33]

its gotta be the air/fuel mixture screw

[Provost33]

ok, so i adjusted the air/fuel 1 7/8 turns out. and it run awesome without an air filter but with the stock one it bogs it down..im hoping the bigger carb and aftermarket filter will help that

[paulpauly7]

you should have gone with a motor swap its easyer than trying to tune a big bore spree with a stock pipe .I hope you dont fry it .Did you read the instructions be for you started it ?

[patthesoundguy]

With the new bore kit, you need to mix 35:1 ratio plus the oil pump. The stock air box needs to be modified according to the instructions that came with your kit or run a uni aftermarket filter. The stock airbox in its stock form will cause a major rich condition hence your possible bog. Follow the break in instructions to the letter or you will suffer a roasted kit.

Sent from my Nexus 7 using Tapatalk 4 Beta

[Wheelman-111]

Greetings:

35:1 premix plus the pump takes you to more than 5% oil to fuel volume. That will be tough to jet for, smoky, prone to carbonization, hot-running, and suck power. With big Malossis, Corsas, Fabrizi 81ccs and even strokers, most tuners run straight premix at 32:1, or 3%. That seems to be enough. Even 40:1 has been reported. Unless there's something I don't know about the 48mm Spree kit, 20:1 is Way too much oil. Your mileage may vary. I do think you should delete the pump and plug the hole.

[Provost33]

I didn't do an engine swap because its more fun to upgrade the engine itself. I'm not looking to do 80mph that's why I have a crf450.

I don't remember seeing any instructions with the kit. I'm sure they were there I just didn't notice it and of course I tossed all the packaging... im going to wait until the 21mm carb comes in and run that with a uni filter. I did drill a 3/8 hole in my exhaust and welded a nut over it so I can put a short bolt in it to quit it up if I want.

I might try 40:1 oil mix plus the oil pump and see what that does for me

[Wheelman-111]

Greetings:

Most people delete the pump and install a plug when they assemble. Wheelman isn't most people. My first big-bore assembly was an '87 Aero with Polini 47mm, stock everything else at first. I decided to retain the oil pump as you have done, simply because I didn't have access to a plug right away. The bigger displacement needs more oil than the stock 50cc pump can supply for sure, but not THAT much more. I ended up putting a couple thousand miles running the pump - which we figured supplies about 40-50:1 AT 50ccs - plus I ran 64:1, then 90-ish:1 in the tank. Never had a problem with the Polini or the next Malossi bore. I do realize that the Tai-made Spree 48 isn't Polini or Malossi, but the amount of oil needed shouldn't vary that much.

The first 51mm ministroker I built, I decided to run 25:1 (Like 1950s outboard motors...). Like those old motors, it smoked horribly, was way under-jetted (due to the oil supplanting nominal fuel content) and lived a very short and ugly life. Sure there were other issues with my build, but too much oil was among them. Try 64:1 + Pump if you can't get a plug right away and want to "insure", but the more important thing is to inspect for and if necessary chamfer the sharp edges on the ports and piston skirts before assembly.
YMMV.

[Provost33]

Thanks a lot wheelman... I'll try 64:1 and inspect it and adjust accordingly.

[patthesoundguy]

The 35:1 was per taz instructions was just for the first break in. The instructions said to lean out the oil after that. Wheelman is right the whole thing will be happier with a leaner oil mix.

Sent from my Nexus 7 using Tapatalk 4 Beta

[Provost33]

OK ya that makes since...thanks.I'm not going to run it until I get the new carb and air filter on now