My new Honda Minibike

[YamaGeek]

Originally Posted by btcn

Yea I'll have to figure me somtin out for them lights.

As for the forks I'll fix the bike first and take it to 55 and see what happens! No just kidding first I'll look into fixing them and then gradually take it to speed and see if its reasonably stable or not.

I'm about to go take it apart and look into that there clutch right now.

Also what kind oil do these little motors call for? Would 10W40 Synthetic Motorcycle oil be fine?

Probably, but frankly, and for the life of my really abused SL90 I had as a teen, it was ran on Delo 100 30#, the same oil used for Diesels in the 60's and 70's. My Father had a 55 gallon drum of the stuff. I still use Delo 15-40 in my 4 stroke bikes today. It works, it's made for older diesels with OHV and lifters. Not to start an oil argument, but we also used the same oil at the scooter shop I worked at.

[btcn]

Ok that sounds like a good idea for the oil I'll try it.

[btcn]

Well, I haven't gotten much progress on the Minibike. But I messed with it a little. And something quite strange is going on with it.

Ok for starters I adjusted the clutch cable and now it pulls all the way out. Its a bit sticky and takes A LOT of force but it pulls all the way back. Only worry is snapping the cable.

It seems to work. So heres the deal. The weird thing is it has to be in neutral to kick it over, if its in any gear with the clutch pulled in it jumps forward when you kick it over. Then if I put it in neutral but I pull the clutch in, the kick starter won't do a think, it just kicks with no resistance. Upon starting it, I can pull the clutch in, pop it in 1st, and release the clutch as you normally would on a motorcycle. It'll start going just fine, then when I get a little distance, maybe halfway through my parking lot it'll start sounding and feeling like I'm pulling a semi truck trailer pull of rocks. If I let off on the throttle it'll rev up a little and go for slightly longer before dying and locking up. If I floor it it starts pulling hard and sounding like its seizing and then die. It also does this sometimes and other times it doesn't. Sometimes it goes fine, but always if I floor it especially in higher gears it'll bog and either need to slow down and downshift or die. Then it locks up. Sometimes it'll restart and sometimes it takes a while.

Also sometimes when I kick it over the kickstart lever starts giving no resistance like its spinning freely, and sometimes with every kick it gets harder and harder and harder, feels just like the engines seizing. It may stay that way for a while, or it may start right up next kick.

I'm really not sure if its the engine seizing, the Clutch/Tranny, or both. Also a lot of times if I click it into neutral when it acts up it'll stay running, sometimes rev freely and sometimes bog down and die.

Any ideas?

[Woodsrat]

Pull the clutch cover and clutch apart and let us know what you find. Also on most engines with the clutch on the crank you can't start them in gear--without me going to a parts site to check is the SL-90's clutch on the crankshaft?*

Also for what it's worth I just picked up a Lifan 125cc four speed semi-auto with the carburetor and electrics brand-new with free delivery for $300 off of eBay. Manual clutch versions are available at the same "Buy It Now" price. These are genuine bargains--I was going to disassemble the 88cc motor out of my fiddy, freshen it up and drop in a four speed but at this price how can you refuse???


*Edit--Apparently the SL-90 does indeed have it's manual clutch mounted to the crankshaft, going by pictures on-line of it. This explains why nothing happens when you pull in the clutch and try to kickstart the bike. It must be in neutral to kick start it. If the bike is in gear--and you disengage the clutch to try to kick start it--you've stopped the motion created by the kickstart and primary gears from turning the crankshaft.

[btcn]

Originally Posted by Woodsrat

Pull the clutch cover and clutch apart and let us know what you find. Also on most engines with the clutch on the crank you can't start them in gear--without me going to a parts site to check is the SL-90's clutch on the crankshaft?*

Also for what it's worth I just picked up a Lifan 125cc four speed semi-auto with the carburetor and electrics brand-new with free delivery for $300 off of eBay. Manual clutch versions are available at the same "Buy It Now" price. These are genuine bargains--I was going to disassemble the 88cc motor out of my fiddy, freshen it up and drop in a four speed but at this price how can you refuse???


*Edit--Apparently the SL-90 does indeed have it's manual clutch mounted to the crankshaft, going by pictures on-line of it. This explains why nothing happens when you pull in the clutch and try to kickstart the bike. It must be in neutral to kick start it. If the bike is in gear--and you disengage the clutch to try to kick start it--you've stopped the motion created by the kickstart and primary gears from turning the crankshaft.

Makes a lot of sense. One question which side of the crankcase is the clutch on? Is it on the right side or left?

[Woodsrat]

The clutch is on the right side as you sit on the bike.

[btcn]

Originally Posted by Woodsrat

The clutch is on the right side as you sit on the bike.

Ok thanks I'll probably pull er about this weekend. Thought I could getaway without doing it but no choice. I don't mind it though, fun pullin motors apart! Just don't have experience on these Horizontal style motors, I've had a CRF 50 for years but their so bulletproof theres never a need to pull the motor apart! Oil and gas and they'll go forever.

I'll take some pics and let you guys know what I find.

[YamaGeek]

It sounds like a combination of carb and clutch\transmission problems.

Simple things first, I'd disconnect the chain and try to isolate the engine running problem first, one of our local inmates had a CT200 that the clutch plates friction material disintegrated on and it caused no end of problems while they were flying apart. I'd also drain the oil and see if there's any metal shavings and other swarf in the sump, get a new clutch cable if the old one is rusty or really worn.

[btcn]

Originally Posted by YamaGeek

It sounds like a combination of carb and clutch\transmission problems.

Simple things first, I'd disconnect the chain and try to isolate the engine running problem first, one of our local inmates had a CT200 that the clutch plates friction material disintegrated on and it caused no end of problems while they were flying apart. I'd also drain the oil and see if there's any metal shavings and other swarf in the sump, get a new clutch cable if the old one is rusty or really worn.

Ok I'll do just that. Yea the Clutch I'm sure has some issues. I think the carb probably may not be jetted correctly, cause I noticed it doesn't got no filter at all, just a little screen. Maybe it is jetted correctly though, but usually its good to have alt least a small air filter.

Also the only thing holding me back is I'm thinking that I'll need a new crankcase gasket when I put the cover back on, and I don't know how hard that could be to find but then again either way it does need to be pulled apart either way.

[btcn]

Ok I was about to take it apart Sunday but right before I did I took it for a little spin around the block. The clutch really seems to be working now, I'm really starting to lean towards carb issues. Reason is when it cuts out it just feels like a carb thing, plus even when I shift into neutral it does it. I also noted its also hard to restart it after it cuts out.

Another note is it seems to run much better when I warm it up for a few minutes prior to riding it. I'm really starting to think maybe it is some sort of carb issue or something. The Clutch may be worth looking into, but a new cable and maybe new plates and oil change should solve any problems with it.

The carb has no air filter, just a little metal screen. Maybe theirs like not enough back pressure or improper jetting? It also has a straight pipe for exhaust. Just an idea.

Also when I floor it it always cuts out if I'm in gear, like the engine can't take a load. If I slowly roll on the throttle it usually will slowly go faster and faster and the RPMs will go up, but then if I floor it it starts cutting out and won't restart easily and when it does it does the same thing in gear with any amount of throttle.

[YZman]

Ya know ya keep dancing around it but what you need to do is.

1. take the carb off and clean it

2, take the clutch apart and figure out what the hell is going on in there. Chances are the plates are just stuck together. pry them apart, sand the steel plates a bit and put it back together.

3. take the clutch cable off and lube the hell out of it if it can even be brought back to life. I would suggest taking the entire cable off and soaking it overnight in brake fluid to try and knock the crap loose inside the housing.

Do those 3 things and youll have a whole lot better idea what is going on inside there.

If you cant figure out how to work on the clutch just post up some pictures of what your puzzled about. Somone on here will know how to get you thru it. But untill you get that side cover off you wont know what is in there.

[btcn]

Originally Posted by YZman

Ya know ya keep dancing around it but what you need to do is.

1. take the carb off and clean it

2, take the clutch apart and figure out what the hell is going on in there. Chances are the plates are just stuck together. pry them apart, sand the steel plates a bit and put it back together.

3. take the clutch cable off and lube the hell out of it if it can even be brought back to life. I would suggest taking the entire cable off and soaking it overnight in brake fluid to try and knock the crap loose inside the housing.

Do those 3 things and youll have a whole lot better idea what is going on inside there.

If you cant figure out how to work on the clutch just post up some pictures of what your puzzled about. Somone on here will know how to get you thru it. But untill you get that side cover off you wont know what is in there.

Yea, your right I have nothing I need to do this weekend so why not get down to it? Your right I've just been putting it off thinking its gonna fix it self. But what have I got to lose? I'll pull er apart tomorrow and let Y'all know what I see in there! And probably take some pics!

[Woodsrat]

While searching for a sprocket for my Lifan 125 (they use the larger output shaft and not the early Honda-style splines) I noticed on one of the pit bike parts sites that the "outer rotor" ignition I mentioned in an earlier post apparently does come with lighting coils. It's simply a smaller, more compact version of the larger flywheel/stator combo used for years. This means that the Pitster motors equipped with this setup can be used to power lights (with a suitable rectifier/regulator). If you throw in the towel on the SL-90 motor and decide to swap to another motor keep this in mind. Might even be a good idea to ask whoever you order from if the motor you're buying comes with a lighting-suitable stator. The early Pitster motor I have on the shelf came with a big flywheel but no lighting coils on it's stator.

[btcn]

Originally Posted by Woodsrat

While searching for a sprocket for my Lifan 125 (they use the larger output shaft and not the early Honda-style splines) I noticed on one of the pit bike parts sites that the "outer rotor" ignition I mentioned in an earlier post apparently does come with lighting coils. It's simply a smaller, more compact version of the larger flywheel/stator combo used for years. This means that the Pitster motors equipped with this setup can be used to power lights (with a suitable rectifier/regulator). If you throw in the towel on the SL-90 motor and decide to swap to another motor keep this in mind. Might even be a good idea to ask whoever you order from if the motor you're buying comes with a lighting-suitable stator. The early Pitster motor I have on the shelf came with a big flywheel but no lighting coils on it's stator.

Thanks for that info, I am starting to lean towards a Lifan, but not quite ready to throw in the towel.

As for the bike, got a little time to work on it Saturday so I cleaned out the carb and put it back on. Noted one of the bolts was improper and the bolt stripped on it's way out! Appears that just the bolt stripped and not the carb manifold screw hole on the head. I had to remove the whole metal tube thing with the carb on it cause there was weird bolts in the end of the manifold where it attaches to the carb that had nuts on them and would be a PITA to remove. The gaskets still there, looks a bit old and dried but seems to still be effective.

The carb seemed to be pretty clean actually, but sprayed some carb cleaner anyways and blew compressed air through the jets and made sure they weren't clogged.

Put it back on and the bike wouldn't even attempt to start! But with the stripped bolt on the left it probably was leaking air now. It was already hard to start before anyways. So I'm gonna go get me one of them new bolts.

But then I decided to start pulling it apart, it won't run now anyways. I kicked it and kicked it and not even tryin. Sometimes the kick starter feels like to easy to kick and then it gets hard like its seizing and then goes back to normal.

So I pulled the cover off to see the clutch but right as I did my friend who I'd planned to ride with on a 2 day ride pulled up on his bike. So we looked at it and I didn't see anything to obvious, so I decided to start disassembling the clutch next weekend. I'll keep Y'all posted.

[Surfernick]

I know this is a year late - did you replace the SL90 engine in your bike? If you did, I'm interested in buying it (and I'm in California). Let me know - thanks!