[TheSwinkster]

I have a 1986 TRX350 and I absolutely love the machine. Tough as nails and does everything I want it to do, it’s got 26x10 kenda executioners in the front and 26x12 in the rear (that might be part of my clutch slip). When you take off, it seems like it slips quite a bit but once it catches, it’s fine. It doesn’t slip again unless you try to short shift it between gears, and if the rpms are down it will slip a little until it gets midway in the rpm range and then it catches and is fine. It isn’t a major issue, but if you’re running it hard and shift between gears and get right back on it, it will slip unless you let off a little and allow it to catch. I know that the secondary (change) clutch is slipping because of that. Clutch has been adjusted and no difference has been noticed in its behavior. I plan to replace the change clutch fibers, steels, and springs with the EBC dirt racer kit in the near future, that kit has worked very well for my mud bike and it hasn’t once slipped. My real question is this, since many of the primary (centrifugal) clutch parts are discontinued. Will the clutch weights, springs, and possibly drum for the primary clutch fit from a 300? I’ve had it apart once before when doing the timing chain when I rebuilt the top end and noticed it has the skinny primary clutch in it as compared to a foreman 450 clutch. Will these clutch parts interchange from a 300 to a 350d? If I’m taking the cover off anyways I’d like to just rebuild both clutches and be confident that my problem will be fully resolved and the bike will be ready to go for another 33 years. I’ve been a long time reader of this forum and many of its members have helped me resolve issues many times, and I assumed this would the forum to join to ask this question. Thank you for your helpful contributors and sorry for the long read!

 

[Goober]

I’ve heard of other clutch swaps (300-450) but not going to a TRX350A or D. Could be @fishfiles, @Manny or some of the other adventurous members could advise.

 

[TheSwinkster]

It would be incredible if I could swap to a 450 primary clutch. We own three of those and two of them are mud bikes, I’ve got a box slam full of clutch parts for them

 

[fishfiles]

I don't know much about 350D's , except I killed a bunch of them for their rear ends ----I put a 300 clutch , cage and primary in my 450 for a 14.5 reduction ----- it is getting hard to remember all the mods I have done , would have to look back at threads , if I remember right , the 300 takes the same disc and frictions as the 450 , just 2 more in the 450 , so the part numbers are different , but they interchange , so I was getting both kits for the same price , buying the 450 kits and putting them in both the 300s and 450s , save the 2 extra every time on the 300s and get a free set after a few clutch jobs -----

 

[TheSwinkster]

I don't know much about 350D's , except I killed a bunch of them for their rear ends ----I put a 300 clutch , cage and primary in my 450 for a 14.5 reduction ----- it is getting hard to remember all the mods I have done , would have to look back at threads , if I remember right , the 300 takes the same disc and frictions as the 450 , just 2 more in the 450 , so the part numbers are different , but they interchange , so I was getting both kits for the same price , buying the 450 kits and putting them in both the 300s and 450s , save the 2 extra every time on the 300s and get a free set after a few clutch jobs -----

Yes, I’ve done that same thing to two of our 450’s. The 350d also shares a clutch pack with the 300’s and 450’s but the gear on the back of the clutch basket is different and the primary is a 29t on a 350d and a 27t on a 300. Really id just like to know if a 450 primary centrifugal would bolt up and clear the side cover. If it wouldn’t clear but would bolt up to the crank, then I know a 300 primary would still work because the primary gear from a 300 fits a 450, and then I could find clutch shoes and aftermarket stall springs for the primary and turn this bike into a real stump puller without needing a GR.

 

[SamUK]

Here's a tip.... As long as the the gear count matches it will work..

So, if you take two teeth from a secondary add it to a primary, that make sense?

As for fitment, I'm pretty certain it will.. I haven't done this mod myself but most parts are Interchangeable with a small amount of work. For the cost it's worth buying the parts and trying it that's for sure.

 

[TheSwinkster]

Here's a tip.... As long as the the gear count matches it will work..

So, if you take two teeth from a secondary add it to a primary, that make sense?

As for fitment, I'm pretty certain it will.. I haven't done this mod myself but most parts are Interchangeable with a small amount of work. For the cost it's worth buying the parts and trying it that's for sure.

I probably should’ve been more clear in my original post, sorry about that. I’m not interested in changing the primary gear itself, just the drum and shoes for the clutch. I would want to leave the factory setup in if I could find parts for it. I might end up just taking it apart and taking my spare 450 clutch parts and seeing if I can make things work. I would simply get the 300 centrifugal drum and shoes and put that in because I’m quite sure it would work, but if I could make the 450 centrifugal fit it would be a tremendous upgrade with nearly double the clutch surface area and the possibility of a competition stall on an already strong bike

 

[TheSwinkster]

Something interesting I discovered for anyone stumbling across this thread, the primary drive gear for a 350d and a foreman 450 (and by extension, foreman 400) have the exact same part number. 23120-HA7-771. This means a foreman 450 and 350d share the amount of teeth on their primary gear, 29. This also means the centrifugal clutch drums will definitely fit on each other’s drive gear, my concern is the 450 primary assembly clearing the engine side cover on the 350d. I will update as I find out anything else.

 

[shadetree]

Something interesting I discovered for anyone stumbling across this thread, the primary drive gear for a 350d and a foreman 450 (and by extension, foreman 400) have the exact same part number. 23120-HA7-771. This means a foreman 450 and 350d share the amount of teeth on their primary gear, 29. This also means the centrifugal clutch drums will definitely fit on each other’s drive gear, my concern is the 450 primary assembly clearing the engine side cover on the 350d. I will update as I find out anything else.

if the cranks are not the same length on the 450 to the 350 ?, then no, the drum will not clear the side cover, least I would not think that it would ?. I dont toss parts at stuff, least not without checking as much as I can. plz update this if/ and when you find out !.

 

[TheSwinkster]

if the cranks are not the same length on the 450 to the 350 ?, then no, the drum will not clear the side cover, least I would not think that it would ?. I dont toss parts at stuff, least not without checking as much as I can. plz update this if/ and when you find out !.

I wouldn’t think it would clear either, but I’m very curious because I’d be quite happy with such an upgrade. I never toss parts at something I’m experimenting with, but since I’d have the cover off already to rebuild the secondary and I have a box full of leftover foreman 450 clutch parts (including two drums) I could easily see if it cleared or not or if only slight modification was needed, etc and just order the new parts accordingly. It may be some time before I carry this out but I will most certainly be updating this thread continually because I know that clutch parts have been basically phased out of production.

 

[fishfiles]

TheSwinkster , there is a guy on Facebook named Bill Byrd , search him out , he has done some amazing things with the 350 , he has one with 44 inch tall tires and Toyota front and rear axles , I would think if any knows about 350 clutch modifactions , then it would be him , I seen videos of that one running thru the bounty holes

 

[TheSwinkster]

TheSwinkster , there is a guy on Facebook named Bill Byrd , search him out , he has done some amazing things with the 350 , he has one with 44 inch tall tires and Toyota front and rear axles , I would think if any knows about 350 clutch modifactions , then it would be him , I seen videos of that one running thru the bounty holes

Thanks for the heads up! I’ll message him about this and see if he has any insight.