1987 mod questions.. help

[oldskoolracer]

OK.

sorry i picked up 1987 yfm350 and i have been trying to put it back
together.

motor was toast so had to pick up new piston and jug so
bought a set on ebay 10.5:1 if i remember correctly


exhaust was gone so i mistakingly bought a crappy dg open ended muffler.

well anyways where am i at horsepower wise?

also where should jets be, well atleast for a starting point.

i have built light brackets for the front i still need to build a tail light and bracket.

i am a big yamaha guy and i'm trying to pick up another 98 warrior.

i sold my blasters to move into these and i rode my brothers and loved it.

i wanna make the best i can but under budget right now

and about everyone i ride with right now have YFZ450's so ill do about anything to keep up/ possibly pass in the future

 

[1998yamahawarrior]

Horsepower wise its hard to judge, but what are all the mods done. Like do you have a filter and other stuff. As far as jetting alot of times you have todo plug chops to get it exactly right.

As for keeping up and passing YFz's, with work they wont totally lose you but you'll never really be able to beat them. On trail riding you may have a chance, but out in the open its usually a no go. YFZ's can just accelerate so quick. Dont want to discourage you from biulding a warrior, its just a fact of life. But with maintenance you will probably out live them!! Warriors are pretty bullet proof!!!

 

[DeadLastRacing]

Yupp yupp, what 98 said.

What size bore are you going with? HP numbers can vary.

Your never gunna beat a YFZ, but you'll sure as hell be able to keep up.

Spend a little time on this site, take a look around and you'll be a warrior genius in no time.

 

['00 WO-YA!]

Yeah man, 450's are just powerful......period. Much more advanced but when they're spare parts your Warrior Will still be around. Not sure exactly what DG you have but maybe it won't be too bad, you can always upgrade later.
For jetting lets try this, 1st, get yourself a good air filter & open up the air box lid. Prolly start with 152.5 main, maybe try a size smaller & a size larger. For your pilot you Will Prolly need a size or 2 up. I have a 45 in mine right now & a 50 ready to go in, I feel like the 50 Will put it about right.
Dude, there's tons of info here in the search forums & tutorials on jetting, exhaust, carbs, clutches, you name it & it's here. Check jets r us for your jets, if Bones chimes in he can Prolly attach a link, he's really good at that stuff, he's totally my go to guy for finding stuff, lol!
You can also do a good carb upgrade on these things, I'm pretty sure that Weston runs a 38mm Mikuni & he raves about it,..... Also, Raptor 350 carbs are a good upgrade. A good cleanup of the head & a nice cam Will help. Depending on where you want your power a Web .390 or Web .430 may be a good choice for your 10.5:1. Piston. I have a big Megacycle .450 but I also plan to run a race fuel mix & 12.1 piston. A good lil cheap upgrade for these things is a timing advance key.
There's just so much man, do yourself a favor & get a few tools to work on it with, flywheel puller & valvespring compressor, these engines are pretty simple if you have stuff to work them with. Have fun with your Warrior, it really is an enjoyable machine.

 

[duneracerweston]

HP 20-23
Jets 42Pilot and 150main to start IMO

 

[1998yamahawarrior]

42.5 is stock you want to go bigger

 

['00 WO-YA!]

Yeah, atleast a 45.

 

[duneracerweston]

in my experience stock intake aftermarket pipe pilot is normally fine anyways but ya going cant hurt sorry about the brain laps dont know what happened there :loco: i must be messing with EFI to much lately

 

['00 WO-YA!]

Haha, Damn Kawasaki is rotting your brain, lol!

 

[duneracerweston]

Haha, Damn Kawasaki is rotting your brain, lol!

But I love it so! Lol I will be back on the warrior in the week thou so don't worry haha

 

['00 WO-YA!]

Sweet man, you're gettin a new cam too! Oh boy, oh boy, Lol!!!

 

[oldskoolracer]

ths biggest thing i have been doing is trying to put it back together, i ride the dunes so i worry about doing the airbox lid MOD, i had it completely stripped down and trying to put some things right, i soaked and scrubbed the air box, replace the fuel lines and filter, tried to scrubb off alot of old paint and built on dirt on the plastics frame etc. the trans is a 5 speed of course and we are heading to the dunes here in a couple months, so will be a little more then trail rides alot of sand highway full throttle running and shooting up dunes. i'm hoping to not have to back down very many dunes for not haveing the power to get up and over.

 

[87warrior917]

Runnin no lid in the dunes would be ok i would think. Running in DEEP mud is a bad idea with an open box. The trans are 6 speeds for all years. 1 down 5 up

 

[oldskoolracer]

actually i have been told by multipul people including the former owner that 87-88' were 5spds. i havent tested it yet only as far as second gear so far. i have seen the outerwears covers that cover the top but worried about rejetting with no lid.

look at my other thread to see running finnally

 

[87warrior917]

All them ppl who said its a 5spd have no clue what there talking about. All warriors are 6 spd.

 

[oldskoolracer]

All them ppl who said its a 5spd have no clue what there talking about. All warriors are 6 spd.

i will take your word for it until i can also test it for myself.lol

i agree any one i have rode was 6spd. but they were all 97 and newer so
i have just gone on others info.


what year is yours

 

[1998yamahawarrior]

The motor in my 99 is from an 87, and its the same as the original motor in my 98. Other than the pull start stuff of course.

 

[beastlywarrior228]

Yep their all 6 it pisses me off when people argue that some are 5 and insist im wrong

 

[oldskoolracer]

yeah i used that pull start a few times driving it around the yard since i dont have a battery for it, dang that thing comes in handy, but dont forget to hit that decompression switch up front OUCH lol.

but it does stick out alot on that side.

 

[elwood]

Wow I thought mine had a powerglide it's a 2speed auto lmao