Stripped splines on drive pulley

[Lift Kit]

Hi, I was given a Honda Spree (after '85 model) today. I got the service manual from this site and started reading the wiki (thanks to everybody whose work has gotten me this far). I tried to turn the engine over with both starter and kick starter, but it only moved the cooling fan slightly. After pulling off the crankcase, here are some photos showing where I am at right now.

Click for big



In the first photo you can see that the splines on the (crankshaft?) are partially worn away. In the second photo you can see that the matching splines on the drive pulley are partially worn, and that one of the teeth that the kick starter engages is kicked right off. I suspect that the person who tried to fix this before me tried to kick start it rather brutally.

SO I have a couple of questions:
1. How reasonable is this to fix?
2. How many parts need to be replaced?
3. Where do I get the parts?

[motormike]

To be properly repaired, this engine will need a new crankshaft.
I would imagine there are contributing factors hiding inside the cylinder...

[Lift Kit]

The cylinder seems to turn over properly when I turn it by hand, it makes a nice "pop" sound and isn't that hard to turn. So I don't think it's seized. Is that what you meant?

And, would this be what I need? http://www.ebay.ca/itm/86-NQ50-NQ-50-Sp ... 776wt_1397

[patthesoundguy]

what a huge drag, I feel for ya.

[motormike]

Yeah Lift Kit...the link you posted is what you need.
I looked at the pix and would not be buying if it were me. Pix lie.
Sometimes you can can be caught in a trap of "throwing good money after bad"
Start spending money on parts and soon you will be invested more $ than the scooter is worth.
When starting with a free scooter, you've got an advantage, but the same possibility still exists.
I do not intend to discourage you from working on this bike, so consider this:
Do a "patch-job" ...MIGHT work for you; weld that gear to the shaft and hope for the best.
Reason for me saying this: If it holds and runs for a while, you're into it real cheap.
If it breaks right away, you're only out some minor welding charges.
And if this doesn't work, repairing or replacing the engine is still an option.

[Lift Kit]

That's a good idea, do you think that JB Weld might work? If not I have a friend who is a welder. I don't want to spend $100 on a crankshaft and find out that it still won't run.

Edit: And one more question, would it help to tighten down the nut on the drive pulley really hard?

[motormike]

JB Weld has it's uses, but not in this case.

Yes, put that nut on tight and weld shaft, nut, and gear all together.
I mean, hey, it's already trashed...

[breaze]

My two cents worth:

I would guess that the damage was done by someone tightening down the nut while doing maintenance without making sure the pulley was properly engaged with the splines (OK, yes, I've done it before).

I had a similar situation and tried filing the splines, etc. - to no avail.

Cracking open the engine and putting in a new crankshaft is the correct fix - will require sourcing a crankshaft, new gaskets, and the tools to do the job right. You'd want to change out the bearings while you're in there. This is a big job and can be expensive depending on how you source a crankshaft. You will find many posts on this subject.

I would agree with Motormike about JB Weld. However, just wanted to note that I used JB Weld on the exact same situation with great success. Put on a new belt, applied JB Weld, torqued it down, and it ran for quite a while. The problem is that any welding type fix may prevent you from going back, splitting the case, and doing it right. I eventually found a new engine bottom end and swapped out - you may be able to do the same and avoid cracking the case.

[motormike]

I would agree with Motormike about JB Weld. However, just wanted to note that I used JB Weld on the exact same situation with great success. Put on a new belt, applied JB Weld, torqued it down, and it ran for quite a while. The problem is that any welding type fix may prevent you from going back, splitting the case, and doing it right. I eventually found a new engine bottom end and swapped out - you may be able to do the same and avoid cracking the case.

breaze speaks with some experience here. The JB weld might do the job since the splines look to have a some teeth that will assist the JB in holding it together for a while. Even if you weld this gear on, repair could be done later with the assistance of cutting torch. I say, try the JB fix...good tip breaze...

[Lift Kit]

Thanks for all the tips guys. I will let you know how it works out. Is there any way to start the engine without the drive pulley installed? I'd just like to know if I have a working motor on my hands or if the problems go much deeper.

[motormike]

Is there any way to start the engine without the drive pulley installed?

With the flywheel cover removed, you can use a drill to turn the crank.
Be sure to rotate the correct direction....

[kingearwig]

I have a used stock af05 crank, kickstarter assembly, and drive face that are in good shape. Would you like to make me an offer on them? Send me a PM.

[patthesoundguy]

If you do decide to weld it all together it would be really strong if you weld it right. And im sure if you ever did decide to replace the crank in it im sure you could just take an angle grinder and a cut off wheel and cut the nut off and grind the welds and cut the end off of the crank and take it apart. Im sure if you replace the parts its going to run. There isnt much left to replace after a new crank bearings and seals. Could you just thread the nut on and crank the engine with a drill?

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[JJ Joseph]

As others have suggested, the cheapest and strongest repair would be to TIG weld a new gear to the shaft. Maybe your welder could replace the broken tooth if he's really handy with the welder and a grinder, and you could make do with the existing gear. It shouldn't cost more than $30 or $40. This repair could last you for YEARS if you do it carefully (make sure no weld splatters onto the threads of the crankshaft). JB Weld is just plastic, and might only last for a short time. But I wouldn't bother rebuilding the existing engine; it's just not worth the bother. Either weld it, or scrap it and with the proceeds buy a Dio or Elite.

[Lift Kit]

Well, I haven't had time to fix the pulley yet, but she runs! I cranked it with a drill on the alternator as someone suggested. I started it the first time with the muffler off, and then when I slipped the muffler back on the engine died. The next time I started it (muffler off again) I had to keep a constant hand on the throttle in order to keep it idling high enough to not die.

I've heard people talk about burning carbon deposits off the muffler - what do you do, just get a hot stove fire going and leave it in the coals for a while?