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[Dieseldude]

I have a 350 Big Bear which works fine in all gears except 1st and 2nd. It's almost as if these two gears are missing and I have to click up through first and second before 3rd will engage................

Any ideas as to what the problem might be - or where to first start looking?

I've done a service with quality Motul oil and the clutch is probably on the way out, but I'm not convinced that the clutch is to blame..............

Also, it's difficult to shift between high, low and reverse while the engine is running but I suspect this is due to the clutch adjustment being out / needing repair.

My main concern is what could be the reason why first and second gears won't engage?

Any help with this would be greatly appreciated.

I look forward to any replies.

Cheers.

Anthony.

[Dieseldude]

Any ideas?

I've been reading my manual over and over and have decided that a new set of clutch plates should help with gears engaging and disengaging - in particular from high range, low range and reverse. At present, if the bike is started in high range and it's shifted into reverse, it won't disengage to allow it to be shifted back to high or low range again.

The clutch adjustment is wound all the way out but the gears won't disengage. Is it correct to assume that new clutch plates will rectify this?

Once this issue is sorted, I will be able to look further into why 1st and 2nd gears seem non existent........

One again, if anyone has any experience with this, or thoughts on the best way to investigate this problem, it 'd be greatly appreciated.

Cheers,

Anthony

[Dieseldude]

Any thoughts?

Surely someone out there has stripped thier Big Bear box over the years or had a similar experience?

Anyhow........

I Just pulled down the right hand side of the engine casing to expose both the primary and secondary clutches.

The primary (centrifical) clutch looks to me as though the contact material has worn down. By my measurement, it's around 1mm thick whereas the manual states that it should be 2mm thick. It also states that if it gets as low as 1.5mm, it is due for replacement.

Should these weights be a snug fit inside their case (drum) when assembled? These, as they are now, have plenty of give before they touch the sides of the drum.

I also noticed that they have groves running lengthwise along the pads. These look factory, and not a result of wear. But - the contact surface of the pads look all chipped as though there has been some debris in there which has chewed the contact surface a bit. Surely this would have contributed to premature wear.........

The secondary clutch, looking down into the basket which is still installed in the bike, looks like the fibre pads are worn. There are still raised pads with definition between them, but only just.

Do these fibre pads ever wear to the point of being absolutely flat? Or do they wear down close to having no grooves (say 0.5mm) and then they're stuffed? I suppose that 0.5mm multiplied across 8 to 10 pads (not sure exactly how many are in there) works out to be a fair bit of give. 0.5mm x 10 pads = 5mm wear and freeplay in the basket. This is a lot when you look at it this way......

Thanks for any info you guys may have with these problems.

I've checked against measurement given in the manual, but I'm only measuring as best I can with a steel ruler and not a set of verniers at this point.

Interested to hear your point of view on this.

Thanks very much

Anthony.


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[Dino]

Dieseldude wrote:

Any thoughts? Surely someone out there has stripped thier Big Bear box over the years or had a similar experience? Anyhow........ I Just pulled down the right hand side of the engine casing to expose both the primary and secondary clutches. The primary (centrifical) clutch looks to me as though the contact material has worn down. By my measurement, it's around 1mm thick whereas the manual states that it should be 2mm thick. It also states that if it gets as low as 1.5mm, it is due for replacement. Should these weights be a snug fit inside their case (drum) when assembled? These, as they are now, have plenty of give before they touch the sides of the drum. I also noticed that they have groves running lengthwise along the pads. These look factory, and not a result of wear. But - the contact surface of the pads look all chipped as though there has been some debris in there which has chewed the contact surface a bit. Surely this would have contributed to premature wear......... The secondary clutch, looking down into the basket which is still installed in the bike, looks like the fibre pads are worn. There are still raised pads with definition between them, but only just. Do these fibre pads ever wear to the point of being absolutely flat? Or do they wear down close to having no grooves (say 0.5mm) and then they're stuffed? I suppose that 0.5mm multiplied across 8 to 10 pads (not sure exactly how many are in there) works out to be a fair bit of give. 0.5mm x 10 pads = 5mm wear and freeplay in the basket. This is a lot when you look at it this way...... Thanks for any info you guys may have with these problems. I've checked against measurement given in the manual, but I'm only measuring as best I can with a steel ruler and not a set of verniers at this point. Interested to hear your point of view on this. Thanks very much Anthony. dieseldude View Public Profile Send a private message to dieseldude Find all posts by dieseldude Add dieseldude to Your Contacts vBulletin Message Cancel Changes Quick Reply The following errors occurred with your submission Okay

They are both shagged, by the sounds of that.
New pads in your centrifugal and new rollers in your variator.
Your right about debris accelerating wear. Lots of dust or mud can do that.
Fix that and then see how the gears are before doing anymore I reckon.
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[Earthmover]

Is it to much trouble to stick some photos or videos up


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[Earthmover]

I'm constantly surprised over how many people are ignored on some forums, equally as how many come to a forum only because thay have an issue or problem and then vanish never to post anything worthwhile again }To the point in question{

I know very little about gearbox's & transmission and in particular big bear 350 1's, only to say that, I did take the time to look at a pdf file on the CVT and gearbox of our bike (CF MOTO 500) and with the limited knowledge i do have with Car & truck Gearbox's.

I'd say you need to look at either the Gear Position Bolt, Spring and Ball or one or all of your SHIFT FORK'S could be bent or just simply worn to thin to fully select the gear and or your SHIFT FORK SPRINGS have lost tension to so as not to hold the shift forks in there desired position. I hope for your sake it's just the gear positioning bolt, spring and ball! but like I have said. I don't know much about this stuff, SO DON'T PULL YOUR GEARBOX APART GOING BY WHAT I SAY
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[Dieseldude]

Earthmover wrote:

I'm constantly surprised over how many people are ignored on some forums, equally as how many come to a forum only because thay have an issue or problem and then vanish never to post anything worthwhile again }To the point in question{ I know very little about gearbox's & transmission and in particular big bear 350 1's, only to say that, I did take the time to look at a pdf file on the CVT and gearbox of our bike (CF MOTO 500) and with the limited knowledge i do have with Car & truck Gearbox's. I'd say you need to look at either the Gear Position Bolt, Spring and Ball or one or all of your SHIFT FORK'S could be bent or just simply worn to thin to fully select the gear and or your SHIFT FORK SPRINGS have lost tension to so as not to hold the shift forks in there desired position. I hope for your sake it's just the gear positioning bolt, spring and ball! but like I have said. I don't know much about this stuff, SO DON'T PULL YOUR GEARBOX APART GOING BY WHAT I SAY

Thanks for your input mate.

These are the kind of suggestions I am after so I have a starting point as to what to begin investigating.

I too have limited knowledge about how these transmissions work, but am mechanically minded so can usually work them out.

I'm new to quads, so was asking incase this is a common issue with older / worn models etc.

Thanks for your input.

Anthony.

[yogie]

Earthmover wrote:

I'm constantly surprised over how many people are ignored on some forums, equally as how many come to a forum only because thay have an issue or problem and then vanish never to post anything worthwhile again }To the point in question{ I know very little about gearbox's & transmission and in particular big bear 350 1's, only to say that, I did take the time to look at a pdf file on the CVT and gearbox of our bike (CF MOTO 500) and with the limited knowledge i do have with Car & truck Gearbox's. I'd say you need to look at either the Gear Position Bolt, Spring and Ball or one or all of your SHIFT FORK'S could be bent or just simply worn to thin to fully select the gear and or your SHIFT FORK SPRINGS have lost tension to so as not to hold the shift forks in there desired position. I hope for your sake it's just the gear positioning bolt, spring and ball! but like I have said. I don't know much about this stuff, SO DON'T PULL YOUR GEARBOX APART GOING BY WHAT I SAY

could you help me to please, I cant get my flux capacitor working proply, oh and dont take too long.

waiting...waiting...waiting.
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[Earthmover]

yogie wrote:

could you help me to please, I cant get my flux capacitor working proply, oh and dont take too long. waiting...waiting...waiting.

That's a new thread entirely

you have enough mates to help you out I thought Oh! and that's not to long is it mate!
So are you any help to this bloke
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[fossil800R]

Have you tried searching for the problem in the Utility ATV section on the Yamaha forum? You will have to join to do so probably but it is a great source of info on all of their gear.


http://yamahaforum.com/forums/
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[PeteW]

I would say probably a shift fork is the cause of your 1st and 2nd gear probs, and if you fit new plates to the secondary clutch and new shoes to the primary clutch then you might get get the HLR gears to shift more easily. Looking at the parts diagram it is a pretty busy gear box with both sets of shafts on the same case. What year is it? the only Big Bear 350 listing I could find is from 1987.
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[Dieseldude]

PeteW wrote:

I would say probably a shift fork is the cause of your 1st and 2nd gear probs, and if you fit new plates to the secondary clutch and new shoes to the primary clutch then you might get get the HLR gears to shift more easily. Looking at the parts diagram it is a pretty busy gear box with both sets of shafts on the same case. What year is it? the only Big Bear 350 listing I could find is from 1987.

Hi, thanks for your reply.

From what I have established, the year of the bike is '88.

I thought I was onto something by ordering a new set of secondary clutch fibre and metal disks from the states. These should arrive this week and I'll put them back together.

I also managed to find a local business in Capalaba, QLD which said that they could rebond my existing Primary centrifugal clutch - so I was extremely happy that I was about to have this side of things fixed.

Unfortunately, I received a phone call this morning stating that they are unable to rebond my clutch and that they couldn't help me. Part of the reason was because the clutch runs in oil, so a particular material is required - and secondly, because the rivets which hold the clutch shoes within the pack are not a removeably item. They didn't seem overly keen on trying to pull it apart and have to put new pins back in when/if done.

Would anyone have any idea as to where else I might try to get this sorted? The price I was given from Yamaha was $520.00 for the new Centrifugal clutch set up.

Thanks very much.

Anthony.

[Dieseldude]

A little update on my issue with the Big Bear.............


I received the new clutch plates / disks and fitted them, put everything back together, went to start the bike to investigate the next problem - and it wouldn't start.

Couldn't get it to start with the pull starter so put the battery back in. The starter solenoid just clicked away, so it was stuffed. Bought a new one, fitted it and now the battery kicks over the starter......................BUT.................. now there is no spark...........

So my bike which ran fine (motor wise) before I pulled the side clutch cover off, now has no spark.

Any idea if this is just a crazy coincidence - or if resting the bike tilted over on the left hand side for a couple of weeks (while waiting for the new parts to arrive) would have caused this.

I suppose the next thing to do is test the Coil, CDI and finally Stator Coil.

I've looked at the fuse, and it's fine............

Might pull every wire connector apart and spray INOX in there to ensure a good connection.

Any suggestions as to why no spark now?

Thanks very much.

Anthony.

[Dieseldude]

Ok, for those who are interested..........

I dropped the quad off at Yamaha to have the stator coil tested on the bike - it bench tested fine.

Yamaha has come back to me saying that it gives voltage spikes when tested on the bike so they assume that it is arching out across the wires leading in and out through the case. They seem confident that this can be easily rectified and is a common issue with a number of bikes including Ducatti, Suzuki and older Yamaha.

I'll find out this week if the repair is a success so will keep you posted.

My next dilemma will be changing gears and picking up gears - my original issue.

I'll keep you updated.

Cheers.

Anthony.

[slightlydodgy]

Sorry if you feel people are ignoring you I have been watching the thread (as I do with most) but havn't felt that I can offer anything usefull
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[06YFZ450]

slightlydodgy wrote:

Sorry if you feel people are ignoring you I have been watching the thread (as I do with most) but havn't felt that I can offer anything usefull

x2

[dangerman4]

Note to self.
Dont spend more on repairs then the bikes worth.

[Dieseldude]

I have good news on the 'No Spark' conundrum.

The mechanic called me today and explained that it took a fair bit of searching all over the bike, but he was able to get it running and idling perfectly (I'm yet to pick it up and see for myself though). Apparently there were a number of faults in the wiring loom such as earth wires running a voltage and switches not contacting etc etc.

I also remember him telling me something to do with the insulation and the 2 wires coming from the stator arching out. This was mentioned, but I have a feeling that this wasn't the issue in whole.

So anyway, he is confident that this part of the problem is sorted, so now it's on to the gear selecting issue.

I have asked that he have a quick play with the bike and try to move it using gears and see what his thoughts are as to why it's not picking up gears.

I guess when I pick it up tomorrow or Wednesday I'll have a mechanics point of view as to where to target next.

Hopefully it's as most of you have said and that it's something like a detent spring or bent selector fork etc and something which is fixable without too much hassle. I'm looking forward to being able to get some good use out of this on the property.

I'll jump back on when I pick it up and let you know what we (Yamaha mechanic) have figured out and hopefully will have a plan in place to get it sorted.

Cheers

Anthony.