line between reliability and hypo

[shiftngeer]

Well i finally pulled my motor to freshen and now i am looking to mod the hell outta it however want it to be fairly reliable.
I understand modding a 2 stroke one generally looses reliablilty....but i am sure there is a line between high hp and reliability.
My advisor, who is a 30 yr career yamaha mechanic....says....most modds aren't worth their unreliablity.

however i am learning to trust some of ur suggestions and high hp mods is why i joined this site!!

I am doing the complete motor top and bottom. currently all stock bore and stroke never rebuilt... in good shape... from 92!!!
suggest away!@!!!!

thanks in advance, dg

 

[super noober]

a nice solid trail machine can be had with some quality porting, FLOTEK is my guy and currently holds the busco beach blaster speed record but there are a handfull of guys that will do u right, ken oconner, chutzell, wildcard, SCD racing . also a +3 stroker crank, good reeds and a good exhaust are great additions. i ran the balls out of mine when it was set up like that and it never let me down

 

[sicivicdude]

Most mods are a trade in reliability and on most vehicles trading reliability for power is an EXTREME trade-off. That's generally in vehicles which are higher tuned from the factory. The good news is, Yamaha started with a good solid platform and left a LOT on the table. You can make a still decently reliable blaster engine that can pump out some HP's.

The other good news is, the blaster is a light and nimble platform... you don't NEED 90hp to make it fast. Just putting out another 10 horsepower is like bolting a JATO rocket on the back of a blaster. Pumping out another 20 horsepower is like having a warp drive...

The first place to start is believe or not, the end. You need to think now about your final goal, your budget, and what you're going to be "happy" with. What are you trying to do with the quad? Drag racing has a far different set of power requirements than a MX quad and MX has a different set of requirements than a trail bike.

Also, consider into your budget everything ELSE that will be needed to harness this newfound power. A stock 1992 model quad has those crappy drum brakes and crappy stock shocks. It's very difficult to harness another 10 hp with the stock stuff on it.

 

[myusername]

a big thing you need to know is your budget. honestly, if i had 2k or so to spend, i'd buy a pipe, v-force reeds, a uni filter and maybe a 28-30mm carb. on the high end, you've just spent 5-600. then spend the rest on a good axle, a arms, shocks and brakes. you'll be much happier if you have 25hp and a great suspension setup than 40hp and a stock setup.

 

[shiftngeer]

Budget.....good point!
Crappy Suspension....very true

first off all the work will be done by me overseen by the yam tech i mentioned earlier. this includes the porting,.......(gasp..)...iknow i heard... i am just going to smooth the ports out......i know not reccomended...... but its fun

second the budget will be $1000 total .....not much these days

third the desired out come- "hooligan quad, moderate trail riding

so commence the scolding, schooling, suggestions and other comments!

thanks, DG

 

[sicivicdude]

Simply cleaning out the ports will increase horsepower a little bit but the main thing it does is smooth out the power delivery.

A factory trained mechanic isn't going to let you buck wild (which isn't going to result in much of a power gain) but will keep you from making mistakes which could cost you your motor later.

A new carburetor and a 400EX rear shock and bushing kit should definitely be on your "punch list". You can live the stock front "pogo sticks" but the one under your butt needs upgrading!

If he'll let you off a bit of the leash with porting, you could probably swing a 34-35mm carb. If it's just a clean-up an OKO 30mm would work well.

 

[myusername]

400ex rear shock... $50
ken oconner bushings for shock... not sure but think its $20 iirc
banshee axle... $100
banshee front shocks... $40
good used pipe... $200
front wheel spacers... $50
Dremel and a few bits for porting... $50
30mm carb... $50
uni filter... $20
Boyesen Dual stage reeds... $30

Grand Total = $610. that gives you $390 to work with and go from there. and money to work with on general maintenance and such.

Keep in mind, this list is a rough estimate from just cruising around on ebay. i'm sure you can find parts cheaper. and this isnt going to make a killer quad, but it will make it alot better than what you have right now

 

[sicivicdude]

^^^^^^^^^^ X2 on everything but the 28mm carb. I think you could run a PJ34 or an OKO 30mm. The PJ34 would require a different intake manifold but that's not eating too much into your budget.

 

[myusername]

^^^^^^^^^^ X2 on everything but the 28mm carb. I think you could run a PJ34 or an OKO 30mm. The PJ34 would require a different intake manifold but that's not eating too much into your budget.

i know after i thought about it i went back and edited it to say 30mm carb. thats something i still need to get for my blaster

 

[Larry's Shee]

First thing you need to do is watch K. Oconners video on porting. Search for all you can find on porting. Start with Gorden Jennings , H. Gramn Bell, McDizzy web site.
Get a flywheel puller ($20) and do timing plate mod for +3 - 4 * advance. Good reeds, Vito's , Boysen, V-3 if budjet allows. Milled and rechambered head about $60, better burn, higher compression.

Your adviser is somewhat correct, John Force makes 3000+ hp for 1/4 mile with the best parts, a street car makes 250+ hp and goes 200,000 miles with mediocre parts. It's all relative. A modded Blaster is way more fun then a turd slow stocker.

 

[Paulie B]

Porting, pipe, carb, lightened flywheel, head milled a tad, and a few degrees more timing.
Forget reeds the price to hp on those sucks.
All that should fit in your budget if your Ebay savy on the carb and pipe.
The rest can be done by Flotek or one of the other reputable builders here.

 

[shiftngeer]

Thanks for the tip on vids by local pros!

 

[1995blaster]

If it was me I would have someone do the porting i know you have help but he can help with assembly.


250 Pipe f7 tooomey lrd lots out there just for the most power dont go with fmf or dg
25 Reeds i think are to much for what they gain id get some 25$ boysean reeds.
75 34mm carb and jets
Porting 200
Head 60 or 75 cant remember
Timing mod free just need a dremel or drill and a flywheel puller
45 i would throw a good tuck clutch in there
175 crank +3 fits right in and can get the porting and the head modded right to it.
100 a wiesco piston
50 gaskets

thats 980 still a couple bucks becuase i probably forgot something

 

[myusername]

whats wrong with an fmf pipe? if he's budget minded, it may be his best bet since they are a dime a dozen. its a good trail pipe anyways. i'm sure vito's dual stage reeds do the same thing as the boyeson reeds do at half the cost, so they may be the way to go. i wouldnt do a stroker crank on a budget build

 

[shiftngeer]

OK the motor is back together and installed. I have broken it in and will post all my results opinions and picture this week!