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Honda spree crank mods. Ya done em? Check out mine.

Posted: Mon Dec 12, 2016 11:57 pm
by stevespree7
I just finish Swiss cheesing my crank. Have any of you done this with positive results?

I'd add a pic but my phone won't let me. I will in the am with my computer. I put 5 , 1/2 inch holes equally across my honda spree crank counter weight to lighten it. And then filled the holes with jbweld. Some people.say I messed up. Some people don't. What did I do?. Lol

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 12:03 am
by Meatball
The milligrams of weight reduction will never be noticed from the saddle...but Im betting the structural integrity being compromised will be a very explosive endeavor...Please be filming when this happens, thx.

If it even runs right at all, Ill be surprised. The crank needs to be harmonically balanced with the weight of the rod/piston/bearings.

I saw a youtube video of a guy that tossed a brick into a spinning washing machine. It jumped around until it finally broke to pieces.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 12:51 am
by MrJumps
Wow thats a first for me to see.

Im gonna bet it wont even last past 10 miles those little nuggets of jb weld are gonna fall out of the crank and go into your top end.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 2:41 am
by eclark5483
That poor Spree. :eyeroll:

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 4:11 am
by Ultraliner
The brick in the washing machine was one of the best youtube vids I've seen all year!

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 7:46 am
by stevespree7
So why have I read like 2 articles where people are doing this?
http://www.dragonfly75.com/motorbike/vibes.html

I am balancing to a Bob weight factor of 25% like a post in moped army said. With Bob weight attached the counter weight far outweighed the Bob weight. So I was merely lightening the counter weight to allow the counter weight to stop drifting to the bottom. As I moved material I drifted to the bottom with less force.. If calculating your Bob weight and balancing your crank is a load of bull, I would be quite suprized. Loads of people for it. I am just trying to learn how..I have 3 cranks to do it. Help me or not

I didn't grind the conrod. I brushed it with a dremel brush. Maybe a bad idea, but I needed to lose a gram. And I am going to drill out the pin as well. So no one balances cranks here? Everyone says the sprees shake with the bbk. That means it needs to be balanced.

I am merely trying what I have read in 3 separate locations and seen in several utube videos.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 7:47 am
by stevespree7
I am merely trying what I read like 3 times and seen in several utube videos.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 8:50 am
by noiseguy
... as long as you balanced the crank, the only issue is creation of stress fracture points.

My point with this would be that the Spree engine has bigger issues than the weight of the flywheel. Namely the sucky stock porting, sucky stock exhaust, and sucky stock intake. Even in the article you posted, the crank is the *last* thing the author was messing with (after addressing the things I just rattled off) and he did it to address very specific vibration issues he noted in testing. Since he was working on cheap China bike engine kits, I'm betting a lot of crap was wrong with engine from out of box...

As for Spree BBK kits... to address this you'd drill holes and add lead to crank... need to make it heavier on the top of stroke... right?

If you have access to a machine shop (not just a press) I'd be really interested to see someone swap a AF16/18 jug onto a stock Spree block. This would require splitting the crank and using the AF16 conrod with larger conrod small end. *That* would be a project.

Anyrate, carry on. I don't think anyone has done this before on this board so I'm very interested in your results.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 10:53 am
by MrJumps
Those jb weld pellets are gonna absord heat slower than the crank and slowly work their way loose into the crank case and reak havic. If you want a lighter crank get the rod replacted iwth a forged rod custom then get your bottom assembly machined out of aluminum at a custom fab shop, then balance the crank and you may see a tiny increase in power, most of what you get from crank mods is throttle response. Besides that your just wearing out a crank faster due to wobble or slap. If anything you get it to rev up higher and the bottom assembly decides it wants to gernade and you have your internals dumped onto the pavement.

http://www.outcropacres.net/images/bs-rod.jpg

Like so except lightning your block too.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 11:22 am
by stevespree7
forgot to mention i have the 22 PWK flatslide carb 100 jet.
a Dio intake with adapter smoothed out for more flow.
dio reeds
BBK
and taz's race gears
and a stock GY6 clutch with crazy lightened clutch arms

i shaved the front pully
and took 1/3 of my contra spring off

i can get to 43 flat on a good day. I am trying everything i can to get to 50 mph. bought 2 more sprees for 50 bucks, using there parts to see what i can mod (or just have replacements for broken stuff, im sure stuff will break)

I have 3 BBK's that i picked up at scooter swap shop when they were on sale. only already blew up but lasted 3k miles (kits arnt that bad at all as long as you tune a little rich) just got a new piston and ring set so after some honing im back to 3 kits to destroy. (not going to try, but may be inevitable)

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 12:02 pm
by Meatball
stevespree7 wrote: I am trying everything i can to get to 50 mph.
I cruise 40-42 on flat all day in my Spree....I bombed a looong crazy steep hill and GPS says max speed was 53. It has stock SE50 motor in it and it didn't even break a sweat.

Sure you can port, polish, shave, trim, mod, extract every drop of juice from the Spree motor and MAYBE hit 50 ONCE. Youd be turning at 12k-13k rpm on a motor that tops out at 8k. Put your money into a variated motor swap. The Spree motor is best left unmodified and ran how it is.

Side note: Did you know that .308 rounds go right through a Spree crankcase?

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 12:28 pm
by eclark5483
SSS has Spree BBK's?
22 PWK?
DIO intake?

Pics please.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 2:00 pm
by noiseguy
graphite9 wrote:the dio bore will never work. and even if you could get it to fit your left with a horribly designed engine and intake/clutch. Also its not just the stroke, its the transfer/boost layout thats different, bolt spacing, all of it.
Several years ago I'd heard someone had done this swap... thought that bolt center for the Dio engine was at least same, but if that doesn't line up, it was either something else, or just a story. I've heard plenty, god knows.

Steve: Given all the other work you've done: rather than lighten flywheel, you need to get a better exhaust. I've hand-built (rather poorly) expansion chambers for Spree in past. On an otherwise stock engine (bore, carb, air filter, literally zero other changes) that was good for +3 MPH top speed *just by* increasing the upper bound of RPM + ~1000 or so. You could get a little more playing with the pulley b/f lack of power at that higher RPM was the limiting factor... best I ever got was 31-32 MPH on the otherwise crummy 84/85 Spree engines (which would do 25-29 in stock form).

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 2:18 pm
by MrJumps
Mod an scorpian to fit the spree, graphite9 have one for real cheap all it needs it the header pipe and a new mount platw to the block and you have the best pipe idea ive seen for a bbk spree get the bore ported by 1man8scoots to the scorpian pipe and than you will have some serious power.

Re: Honda spree crank mods. Ya done em? Check out mine.

Posted: Tue Dec 13, 2016 2:44 pm
by Meatball
The time, money and effort youre putting into this truly commendable. Hats off to you for seeing how deep the rabbit hole can go with a Spree motor. I don't think you'll find any haters on here for you attempting this but there are many theoretical and factual flaws with your plan as stated in previous posts.

If you really want better performance and higher top speed you should focus your efforts and fab skills into somehow fitting a variator to the Spree. With so many interchangeable parts from models domestically and abroad, Im sure theres a combination out there that will get you close to success with minimal fabrication. My theory below:

Replace ONLY the variator half of the crankshaft with one from a bike you choose to use trans parts from. Balance crank as needed. Replace rear 12t drive shaft to accept new clutch. Youd be stuck with the Spree gear ratio (or TAZ gears) because of the Spree case design. Belt length will likely be unique to this mod because of length of Spree case. Belt cover will need to be modified for clearance due to new variator distance and no other OEM covers will fit the Spree case with clearance needed. Kickstart will require savvy fab work to operate but not detrimental to make the vari work. Possibly need to shave a few areas on the inner case for the new belt system to be free of unwanted rubbing.

I bet theres more things along the process I overlooked but "in theory" it will work. Would be a fun project for sure.