Need some guidance on my YFZ repairs/upgrades

[LonesomeTriZ]

Last year I pulled my 2005 YFZ 450 out of moth balls and got it running. It was then I found the water pump seal had gone bad from sitting for so long. I got annoyed then got busy with school and two jobs so it has sat in the garage since. The two things I want to address now are the coolant leak and the charging problem. I have had to buy more batteries than I have had a chance to use. I understand this is a common problem so I just need to know how to deal with it. Also, while I have it apart is there anything else I should address. I read somewhere the earlier models have an oiling issue. Other than a set of Hole Shots it is all stock and has very few rides on it. I just want to get it up to date and repaired properly. Any input?

[ebaccm26]

They do have a serious oiling issue that effects many of them. If your bike has not been ridden much there is a good chance you could still experience this problem. It absolutely needs to be addressed as it can be catastrophic for the engine. Just google YFZ 450 oil mod or oil upgrade.

[LonesomeTriZ]

I did some readin on it. It seems there are a few methods to addressing the oiling problem. I have not zeroed in on the one best for me though.

[86T3]

Do some searches on yfzcentral, you'll find all the oiling info you need. I bought an 08 so im not super familiar with yours but i believe your options are either mod your case half for the oil passage, send it out and have it done, or buy a 07 and up half to replace yours. Im also not postivie but i read about the early yfzs having a design problem where the battery doesnt charge unless the headlights are on. Hopr this can get you in the right direction

[atc007]

Yamaha,Yamaha,Yamaha. Raptor one way bearings.... YFZ's that are junk,unless you pull them down ,split the cases. And repair them yourself.. Grizzly one way clutches,,and on and on and on. This kind of thinking. Supporting a company that does this to their customers. Is completely and totally beyond my scape of reasoning. Lonesome. I have your old tires. I'm betting that your YFZ does NOT have 3 tanks of fuel through it. They make me sick. I have told the unequivocally, if I get a Raptor through here that needs a one way. THEY are going to fix it! Don't get me wrong. I love a sexy yellow 85 Tri Z to look at just as much as the next guy!. But giving them money for a late model buggy is a very bad idea IMO. Good luck Lonesome. Sounds like the internet is gonna have to fix another one :(

[LonesomeTriZ]

I have just done a bunch of reading over on Central. I am going to send my case off to get it machined. Teh charging thing is killing me now. I never knew the headlights had to be on. There has to be a fix out there for it.

I think yo are correct. I have not ran more than a couple tanks of gas through it. So it does bug me to deal with stuff like this on a like new machine. Just goes proves what I already knew. Better to biuld an old one than buy a new one.

[ezmoney1979]

I have an 05 YFZ that I have put an insane amount of hours on, many of them riding double climbing dunes banging off the rev limiter. I only have a Dr.D pipe, exhaust cam retard, pro flo/k&n and adjustable pilot jet. It has been the best quad I have ever owned by far. I definitely need to open it up and do the top end and oil mod but I must have a thousand hours on the stock motor. I'm pretty strict on oil changes. I change it every or every other dunes trip, depending on how its been ridden, with Torco T-4 10-40. I rode it the other weekend and it's still the fastest 450 out of all my friends 450s!
To the op, anything that has a battery that sits needs to be on a trickle charger. Get rid of the stock jetting as it is too lean, my fan never kicks on anymore unless it is super hot and pulling hills. Good luck, they can pop without notice but so can any production motor.

[ezmoney1979]

I have never heard anything about needing to have lights on to charge, that can't be true.

[LonesomeTriZ]

I have read it on several sites now. Either it is a urban legend, or there is some truth to it.

[86T3]

http://www.yfzcentral.com/forum/32-yfz-powertrain/115932-05-charging-problem.html

Post #2.

Bill, the problems with the 450s were the first years only, they got them straightened out pretty quick. I think honda had problems with the crank bearings or cranks on their early ones. IMO, they're just as reliable as the hondas. Dont know anything about raptors and qrizzlys though

[nicker71]

I have an 05 YFZ that I have put an insane amount of hours on, many of them riding double climbing dunes banging off the rev limiter. I only have a Dr.D pipe, exhaust cam retard, pro flo/k&n and adjustable pilot jet. It has been the best quad I have ever owned by far. I definitely need to open it up and do the top end and oil mod but I must have a thousand hours on the stock motor. I'm pretty strict on oil changes. I change it every or every other dunes trip, depending on how its been ridden, with Torco T-4 10-40. I rode it the other weekend and it's still the fastest 450 out of all my friends 450s!



To the op, anything that has a battery that sits needs to be on a trickle charger. Get rid of the stock jetting as it is too lean, my fan never kicks on anymore unless it is super hot and pulling hills. Good luck, they can pop without notice but so can any production motor.




I raced XC with a 2005 yfz for more than two years. I ran it very hard and it took care of me. I never had an oil mod done nor did my crank/crank bearings fail me. Only a couple times did I have issues with my battery not charging, I called my dealer where I bought it from and they got me hooked up a factory fix for the problem. If I remember correctly it was a rectifier.

[LonesomeTriZ]

By chance would you have the OE part number for that?

[nicker71]

http://www.yfzcentral.com/forum/32-yfz-powertrain/115932-05-charging-problem.html

Post #2.

Bill, the problems with the 450s were the first years only, they got them straightened out pretty quick. I think honda had problems with the crank bearings or cranks on their early ones. IMO, they're just as reliable as the hondas. Dont know anything about raptors and qrizzlys though

I don't know about the other models but the yfz was superior over the 450r. Everyone's that races the 450r seems to break the frame up over the engine. Hondas electric start system sucks, crank bearings don't last very long.
to put 04/05 spindles on their 06 plus models. I've been out of it for a few years so maybe things have changed since then?? I sure do appreciate the old honda trikes over all the rest though

[LonesomeTriZ]

When mine would start, I loved it. But I am so very sick of pulling it out, getting it running, just for it to give me trouble when I want to use it. That is one reason it has not been on the trails in 5 years.

[nicker71]

http://www.bluetraxx.com/forums/yamaha-yfz450-450r-2004-present/48103-yfz450-yamaha-tech-updates.html

Here's a link about it. The resister kit is what I had. I also bought a optimate 3 battery charger that I always used between races. And I think I used a cbr600 battery or 400ex battery I don't remember

[LonesomeTriZ]

I did not know there was another battery that would fit in that space.

[nicker71]

I did not know there was another battery that would fit in that space.

Yeah if you cut out the back wall that holds the battery in. Back in 04/05 this is what people were first doing to help with the charging problem. Plus this battery cost a little less. Do you have a good quality charger?? I bought a optimate 3 And would put and leave the charger on it when ever I wasn't ridding. It's a smart charger and won't over charge and damage the battery. This maybe all you really need.

I installed a kick starter on my 07yfz just in case. I'm 200 lbs and I couldn't kick it over, I had a shorter kick lever so I wouldn't have to cut my rear fender but it was just too hard to kick.

[LonesomeTriZ]

I was wondering which charger to get. I knew it had to be a certain kind.