[Thwapp]

Hi everyone,

First off, I'd like to appologize to everyone for the mini novel I'm about to write... So here goes:

As in the title, I have a 1989 Honda Fourtrax 300 4x4. It has a few issues that I'm hoping one of your brilliant minds will be able to help me with.

1 - The carb is wayyyy out of adjustment. The guy I bought this quad from royally f***ed it up trying to get it to run better. I'm willing to bet it was set up pretty good before he messed with it and it just needed a good cleaning, but since I know nothing about how to clean or set up a carb, I'm most likely talking out my backside. I did put some of that magical Seafoam fuel treatment mixed with Chevron 04 octane premium (no ethanol in it!) through the bike and that seems to have done wonders for it already, however at random times, the engine surges like the throttle is being held around 40-60%. After a while, it settles down again. Once in a while it won't start at all, and after I've pulled the spark plug out and cleaned it up, put it back in and she fires right up instantly. The tip of the plug is black when I remove it. Not sure if that's carbon, or oil leakage. I'll try and get a picture to make my description a bit clearer. My hope with this problem is that someone who knows better than I can point me in the right direction to figure this out as it's driving me bonkers.

2 - It has no front brakes. The wheel cylinders that push on the brake pads in the front drums are seized.. If I can't find a front wheel drum to disc conversion kit for this quad, I'm planning on ripping the front brakes out entirely and letting the front wheels freewheel as I've got a rear drum to disc conversion kit from SuperATV to put on, which brings me to my next couple of problems. I'm hoping someone knows where I can get a kit for this quad to convert the brakes from drum to disc. If there isn't a kit, but someone has done it, can I be pointed towards that person so I can learn how to do it and what parts I'll need to accomplish my goals?

3 - The rear brakes. They work, but not the way I want them to. As I mentioned in point #2, I have a SuperATV rear wheel drum to disc conversion kit that I'm going to put on. It has both hydraulic and mechanical brake connections. Unless I can find a front conversion kit, I'm planning on connecting the front hydraulic brake lever to the rear disc caliper in addition to connecting the rear mechanical brake lever and the mechanical foot brake as well. This way, no matter which brake I pull, the quad should stop - or at least, I'm hoping it will work that way. Once this rear disc brake is installed, SuperATV claims the stock rear wheel won't fit properly, which brings me to my final point. Hopefully someone can offer some advice to help smooth out the problem for me.

4 - Tires and Wheels

- Wheels - The SuperATV disc conversion kit is not supposed to work with the stock 11x7 wheels it has on it. Furthermore, finding replacement tires for it is turning out to be a bear of a task as the choices available for the front (23x8-11) and rear (24*9-11) are very limited, so I've decided to go with a set of 12x7 wheels. ITP makes a ITP Black Delta Steel wheel that's supposed to bold right onto the quad. It's also supposed to clear the rear disc brake from SuperATV. If anyone can confirm this, I'd be very appreciative! The other reason I have for going with the 12" rim is that it opens up a plethora of tires to choose from, making replacements much easier..

- Tires - How big of a tire can I put on this quad? I have a 2016 Honda Rubicon 500 DCT EPS IRS 4x4 that I went 1" larger tire size all the way around (26*9-12 fronts, 26*11-12 rears) on 12" rims w/out issue. Because of the 1" tire size difference, I was thinking I'd put a pair of 26x9-12's on the front with a pair of 27x11-12's on the rear for a little bit more ground clearance. Will this work without borkin' my transmission/transfercase?

- Offsets - I read somewhere that I have to watch out for offsets. I know what a 4" + 3" offset on a 7" wheel is and apparently, that's what's on my quad right now. The ITP steel replacement I linked to show a 5+2 offset for the fronts and a 2+5 offset for the rears.. I was wondering if I could just use the 2+5 offset rear wheels on all 4 corners??

So, there's my saga. Anyone have any suggestions? Can Someone possibly confirm some of my suspicions/concerns?

 

[retro]

Lets take it one step at a time... carb first.

Do you have a copy of the service manual yet? If not, you can get one HERE, you'll need it to disassemble, set up and reassemble your carb.

Next up... is your carb a genuine Honda original or has it been replaced with an aftermarket carb? If original, has it been rebuilt using an aftermarket carb kit? I must ask because most of the carbs and kits people buy nowadays are china made garbage and will never work right. Verify that your carb is original and has all of the original parts inside it... then fix it by following the manual. If you have any aftermarket china made parts, replace all of them with OEM.

Keep us posted if ya can...

 

[Thwapp]

Thank you retro for the link to the service manual.. I'm downloading it now and shall peruse it on the weekend when I'm done my week of 14 hour shifts.. I will endeavor to keep you posted, and I'll be taking pictures along the way as well.

 

[retro]

Cool, love the prospect of maybe seeing some photos...

Check out fishfiles' Blue 300 project thread if you get some time... If I remember right he is putting a SuperATV disc brake conversion on the front of his bike.

 

[fishfiles]

first thing I notice is either you or your atv are not from the USA ,there was no 1989 300 4x4 in the USA , so if you are out the country then it may be expensive to ship the disc conversion kit , Super ATV or Highlifter makes them , I just put a SuperATV kit on my 92 300 , they list for $229 , as far as fitting your 89 , I could give you the phone number and you give them a call

 

[fishfiles]

as far as tire size goes , I run 26x12x12 on the rear and 26x10x12 on the front , I run aluminum rims so I run 1 inch spacers on the front so the calipers of the disc conversion don't hit the rims , you can grind the corner off the caliper and not use the spacers , this grind mod is sanctioned by SuperATV now and is stated in the instructions , the 26's are the limits with going to a gear reduction

 

[fishfiles]

as far as I know there is no rear disc conversion for a 300 rear end , could you link me to what you got , I think what you got is not going to fit

 

[Thwapp]

as far as I know there is no rear disc conversion for a 300 rear end , could you link me to what you got , I think what you got is not going to fit

Here's the rear disc conversion kit I got from SuperATV. I live in Canada on the BC coast, but ordered the parts from a Canadian reseller in Calgary, Alberta.

https://www.superatv.com/honda-utility-atv-rear-disc-brake-kit#

 

[retro]

Here's the rear disc conversion kit I got from SuperATV. I live in Canada on the BC coast, but ordered the parts from a Canadian reseller in Calgary, Alberta.

https://www.superatv.com/honda-utility-atv-rear-disc-brake-kit#

From that link:

Fitment

Fits:
Honda 2x4 Utility ATV's with a 12" or larger wheel and rear drum brakes
Honda 4x4 Utility ATV's with a 12" or larger wheel and rear drum brakes

Does NOT Fit:
Models with drum brakes on swing arm
2014+ 420 Models
2014+ 500 Models

 

[fishfiles]

I was told by Superatv that kit doesn't fit on a Honda 300 , the brake drum has to be out against the rim for it to work , did you try to fit it yet , I am very curious

 

[fishfiles]

Here is a pic of that kit on my 450 , on the 450 the brake drum is out on the end of the axle , the 300 has no axle tube on the right side for the kit to bolt to

 

[SamUK]

Here is a pic of that kit on my 450 , on the 450 the brake drum is out on the end of the axle , the 300 has no axle tube on the right side for the kit to bolt to

Is it possible to fit this to a 350d rear fish?

 

[fishfiles]

I wish Sam , the diameter of the 250/350 axles splines is different , seems modifying the kit would be doable ----if SuperATV is listening , maybe they could send me a free kit and I will sure try to make it work and they cam have the patent rights

 

[SamUK]

Ahh ok. 'Could' be modded to fit though?
I was just thinking how often I use the park brake on my 300, even though it's not great! I plan on removing the drum as soon as my front discs turn up see. May end up with a bungee cord on the front brake lever temporarily haha

 

[fishfiles]

the difficult takes a while , the impossible just a little longer ------- some tie wire , duct tape , a BF hammer and some imagination will solve almost any problem

 

[Goober]

Thwapp,

The thing with disc is that the pads are always in contact with the disc--unlike drum brakes the are always reducing hp

Good luck with the carb if OEM you should not have too much trouble.

Please consider renovating the front brakes-You would like them if they worked. I don't think you would improve the rig by removing them.

I just got a 300 and the brakes don't work. I need to replace the long cable plus can't get the fronts to bleed right.

 

[Thwapp]

I was told by Superatv that kit doesn't fit on a Honda 300 , the brake drum has to be out against the rim for it to work , did you try to fit it yet , I am very curious

I phoned Super ATV before I ordered my rear disc kit. I asked a crap-ton of questions of them & I'm sure they were ecstatic when I finally got off the phone with them, too. LOL.. Anyhow, the reason I mentioned this is because they told me it would fit no problem. I'm going to try to fit it on tomorrow, right after I pull my front bumper back out from the plastics on my 2016 Honda Rubicon 500 that I crashed into a tree today while riding. (pics attached of the carnage... *Sigh* And a pic of the airtime I got while riding a week ago!)

I'll take some pictures before, during, and after and post them up here showing what I've done (or not done, whatever turns out to be the case).

I'm going to leave the carb alone for now and focus on the wheels. Considering how bad the spark plug looked when I changed it last weekend, I think I may have some engine work to do as well, so I'm going to tackle that issue next..

But first, I was given a pair of 25x10-12 ITP Mud Lite tires today that I'm going to put on the rear of the 300, hopefully using the original steel wheels that came on my 2016 Rubicon. Right now, there's a pair of 24x9-11 ITP Mud Lite tires on the rear. I'm going to throw away the old stock tires on the front 11" rims and discard the rear 11" rims, moving the rear tires to the front rims in the process. That will give me a practically new set of ITP Mud Lite tires on the quad, preserving the 1" difference between the front and rear tires as well. That should also neatly fix my potential clearance issue with the rear disc caliper and the rear rim. If there's contact between the disc kit caliper and the 12" rim, I'll put a spacer on and hope that does it.

Regarding my front brakes, I priced out the parts from Honda to rebuild the front drums and damned near fell over in shock when I was quoted almost $700 CAD, which is still quite a chunk of change converted to USD! I'm not willing to pay that, which is what started me on the drum to disc conversion kits in the first place. If anyone knows of a front wheel disc conversion kit that will fit my 89 fourtrax 300fw, I'd be very interested in hearing about it!

Anyhow, I must be up in about 6 hours, so I should get to bed.

 

[Thwapp]

Thwapp,

The thing with disc is that the pads are always in contact with the disc--unlike drum brakes the are always reducing hp

I've never had that power loss experience with disc brakes. I HAVE had that sinking feeling when your drum brakes stop working because the drum has filled with water and fouled things up, usually discovered when you need them the most!

 

[Thwapp]

Here is a pic of that kit on my 450 , on the 450 the brake drum is out on the end of the axle , the 300 has no axle tube on the right side for the kit to bolt to

Fishfiles, thanks for the pic! It's good to have an idea of what they're supposed to look like once the kit is assembled!

 

[Thwapp]

Does anyone know if the offset on a 2016 Rubicon 500 12" rim is the same as that on the 89 Fourtrax 300FW? I'm having a bear of a time finding out what the offset is on the 2016. If it's the same, or darned close, I shouldn't have any trouble at all using the rear rims from the 2016 on the 1989..