Right Clutch?

[Lindy]

Just put a new HF Predator in a DB30S. Gas tank is a little snug at the top but workable. I bought the attached clutch and thought it would fit but if I slide it on (sprocket out) it only slides on half way. If I flip it around (sprocket in) it won't fit on at all. Did I buy the wrong clutch or am I doing something wrong?

 

[buckeye]

May be a dumb question, is your set screw backed out enough to allow it to slide on?

 

[Lindy]

I didn't even put the set screws in yet. Seems like it goes into the torque converter fine and then hits the sprocket and stops. I didn't want to force it.

I don't feel (or see any) ridges or burrs on the shaft or in the clutch. Is 3/4 inch the right size for a new HF?

 

[T-Town Mini]

If there's no obvious burr or ridge preventing the sprocket side from sliding onto the shaft then there may be some taper to the inside diameter of your clutch.

Measure the ID on each end of the clutch's bore and check that it's identical either way. It should be within a thousandth of an inch. If you don't have a caliper or machinist's scale you can still use a tape measure or ruler and eyeball it to either side of a 1/16th mark. If it's not exact then call wherever you got the clutch and talk it over with them. They may just exchange it for you.

You might try polishing it with some fine sandpaper (320 grit or higher) and see if it'll fit then.

 

[Lindy]

Thanks. I'll try that this evening after work. I bought the clutch from OldMiniBikes. Should I call them first, before I try the sanding? I don't want to have an issue returning the part, if I sand it first. Thoughts?

 

[T-Town Mini]

Definitely call OldMiniBikes first. That's the best course of action and you can do that right now.

Keep the thread updated to let readers know the results....and, post some pictures of your bike, too.

 

[Havasu Dave]

If it goes on half way with the sprocket out, then hangs up when you reverse it, you have burrs on the clutch and probably the crank.

Yesterday I was playing the same game with a brand new jack shaft, and brand new collars. I couldn't see the burrs with my naked eye, and couldn't feel them inside the collars. (no room for my fingers)

I spent a lot longer than I should have with a found file (rat tail file) removing the burrs that occur when you tap holes for set screws.

You have the right parts, just some virgin territory, coupled with some threads bulging into the machined area.

FYI- Max now says to allow the clutch to track a bit on the shaft in a chain application- in other words, to use the crankshaft bolt and washers for spacing but no set screws.

File away. :grind:

 

[jdogg]

Seems like it goes into the torque converter fine and then hits the sprocket and stops.

Hey Lindy! What torque converter are you reffering to? Is this not going on the engine shaft? :shrug:

 

[Lindy]

Sorry - Should've said "it goes into the clutch fine and then hits the sprocket and stops". I have a Rupp Roadster too (no clutch but torque converter) and just misspoke.

I'll post some pics tonight of the DB30S. Nothing special but my son wants to ride and the Rupp HS40 is always giving me problems.

 

[jdogg]

Sorry - Should've said "it goes into the clutch fine and then hits the sprocket and stops". I have a Rupp Roadster too (no clutch but torque converter) and just misspoke.

I'll post some pics tonight of the DB30S. Nothing special but my son wants to ride and the Rupp HS40 is always giving me problems.

Ok Lindy that makes sense! :laugh: Let us know if you get it to work and what the problem was! :thumbsup:

 

[Lindy]

Ok - did a little work on the clutch (filing and sanding) and finally with a little help of the rubber mallet, was able to get the clutch on. A bit snug but should be okay.

A couple last questions:

> Should there be any spacers/bushings on the shaft between the motor and the clutch?

> What's the consensus on using the clutch set screws?
> Finally, what's the best way to align the clutch and the wheel sprocket? Just eye it up or is there a trick to it?

Here's the bike. Picked it up for a $100 on CL. Front fork was bent, replaced all the bearings, and had to replace the back tire but everything else was good.

 

[jdogg]

Hey Lindy im hearing more and more that no spacers are needed and it should float for its own alignment so no set screws. But I have not had a problem with a 3/4'' machine washer as a spacer! I use a straight edge/flat straight bar and clamp it to rear sprocket then adjust engine/clutch gear to match! :thumbsup:

 

[jdogg]

Heres a good link or two

http://www.oldminibikes.com/forum/h...94223-max-torque-clutch-install-question.html

and

Clutches

so now you just have to make a decision :laugh:

 

[C9H13NO3]

Ok - did a little work on the clutch (filing and sanding) and finally with a little help of the rubber mallet, was able to get the clutch on. A bit snug but should be okay.

A couple last questions:

> Should there be any spacers/bushings on the shaft between the motor and the clutch?

> What's the consensus on using the clutch set screws?
> Finally, what's the best way to align the clutch and the wheel sprocket? Just eye it up or is there a trick to it?

Here's the bike. Picked it up for a $100 on CL. Front fork was bent, replaced all the bearings, and had to replace the back tire but everything else was good.

No you don't need any spacers of any sort. As long as you have a bolt with a washer that has an OD larger than 3/4", you'll be fine. It sounds like your clutch is a bit of a snug fit (hence, mallet) so you should be fine without set screws.

I've used set screws on some bikes and skipped them on others. Didn't see any noticeable difference.

Just my opinion.

 

[Lindy]

Thanks for all the information. I'm going to get that all set up this evening.

The last question is related to the chain. I bought a new one and read I might need to take a couple links out. Sounds like I might need to invest in a chain breaking tool. Any other way to adjust the length or should I start searching for one of the tools on the internet this morning?

I'm also going to do a search as soon as I finish this post. Maybe there's some information out there already.

 

[Camjamsdad]

I bought an arc chain break on ebay for $15.99 its been awhile but worth checking into.

You can use a punch and hammer, or a small nail/screw and a vice to push the pin out of the chain but the break is the best easiest and slickest way. I rarely use master links unless I'm lazy, not at home, or can't find my break.

 

[JKautoFab]

this is the first ive heard about this not using set screws and letting the clutch float on the shaft. i guess it makes sense, but would it apply to yard karts? the max torque site seemed to be mainly talking about race axles and staying in the race after a crash by not throwing your chain. I have wrecked a few yard karts but dont think i ever had an axle move.

ive got a baja warrior with a subaru robin that i think i will have to use the set screws on... theres a broken bolt and a broken easy out in the bolt in the crankshaft. i imagine my only other option is to tack weld a washer on the end of the crank to keep it from flying off! i dont think the set screws will be a problem on the baja or a yard kart though..... i dont see how it would effect our minibikes unless your initial line up was off

 

[jdogg]

this is the first ive heard about this not using set screws and letting the clutch float on the shaft. i guess it makes sense, but would it apply to yard karts? the max torque site seemed to be mainly talking about race axles and staying in the race after a crash by not throwing your chain. I have wrecked a few yard karts but dont think i ever had an axle move.

ive got a baja warrior with a subaru robin that i think i will have to use the set screws on... theres a broken bolt and a broken easy out in the bolt in the crankshaft. i imagine my only other option is to tack weld a washer on the end of the crank to keep it from flying off! i dont think the set screws will be a problem on the baja or a yard kart though..... i dont see how it would effect our minibikes unless your initial line up was off

This was kinda my thoughts too! Dont know if they took into account mini bikes where the engine is pitched side to side as the bike turns. I would think that would throw a chain with the clutch going out off alignment by its own weight when you turn? Also wouldnt the clutch be locked up against the keyway on the crank under power and wouldnt "float" anyway?