Question for top techs

[challett3]

Any ideas about why two quads with the exact same mods run completely different.

Both have 13:1 JE pistons, Hot cams stage two, 14t fronts and 185 main jet, modified airbox lids. All of this was installed by the same person.

Here is what is happening one quad flat out pulls away in second and never looks back. After running thru all the gears one quad is about three to four quad links faster. We even changed riders and the same results.


Any ideas?

[roughrider01]

Originally posted by challett3
Any ideas about why two quads with the exact same mods run completely different.

Both have 13:1 JE pistons, Hot cams stage two, 14t fronts and 185 main jet, modified airbox lids. All of this was installed by the same person.

Here is what is happening one quad flat out pulls away in second and never looks back. After running thru all the gears one quad is about three to four quad links faster. We even changed riders and the same results.


Any ideas?

What do they have for exhaust?

[challett3]

The exhaust is the slower quad has slip on yoshi and the faster quad has pro circuit-4

[chad502ex]

you've answered your own question

[mikes450r]

i also heard that honda dynos 1 out of 10 bikes..so they set one up nice and perfect...and do the dynos on that one.

[roughrider01]

Originally posted by mikes450r
i also heard that honda dynos 1 out of 10 bikes..so they set one up nice and perfect...and do the dynos on that one.

People usually use dynos to jet there machines to gain the most power, honda puts the same jets in every 450r.

[Jersey450R]

Originally posted by challett3
The exhaust is the slower quad has slip on yoshi and the faster quad has pro circuit-4
pretend pro circuit is Mario and The yoshimura is...well...Yoshi. Yoshi is always slower!

[challett3]

I can't imagine that the yoshi is that much slower than the pro circuit.

We are talking about 3-4 bike links.

IF yoshi is this bad, what is everyone using with for exhaust with these kinds of engine mods?

[perf.m.s]

I wouldn't think it was anything to do with exhaust, but I'm not an expert. I would think it might be something maybe with the clutch. When you find out post it, so we all can learn from it.

[jshtex]

Easy enough to see if it is the pipe.... Swap them and see, heck it couldn't take too much time and you would know for sure. I bet everyone here would like to know the outcome.

[BOONE450R]

you need to tell them its a Yoshi comp not a TRS
and as always Jersey & Chad your letting your ignorance shine, what pipe is on the Suzuki that one the MX title last year?:macho

[challett3]

yes it is a yoshi comp. I will switch them out this weekend and post the results.

I have to think that it is not the pipe, but the only way to fix things is by process of elimination

[chad502ex]

Originally posted by BOONE450R
you need to tell them its a Yoshi comp not a TRS
and as all ways Jersey & Chad your letting your ignorance shine, what pipe is on the Suzuki that one the MX title last year?:macho

look, is the only thing that makes you feel better is to try to bust my balls? The only thing I said in this whole thread was that he answered his question. BTW, that's not how you spell "always", "all ways", LOL talking about ignorance.

[BOONE450R]

damn chad you got me:blah:

[Thump_It]

The Yoshi Comp Slip-on isn't much better than a stock pipe. It might help a little. The Pro Circuit full system would be much better than the Yoshi Comp. Now if you get a Yoshi Pro TRS, you'll pull ahead. But as you are going to do, switching the pipes out would be the best comparison obviously. If it isn't the pipes I would imagine it would have something to do with the clutch as mentioned earlier. Okay I'm done blabbing....can anyone back me up?

[chad502ex]

Originally posted by Thump_It
The Yoshi Comp Slip-on isn't much better than a stock pipe. It might help a little. The Pro Circuit full system would be much better than the Yoshi Comp. Now if you get a Yoshi Pro TRS, you'll pull ahead. But as you are going to do, switching the pipes out would be the best comparison obviously. If it isn't the pipes I would imagine it would have something to do with the clutch as mentioned earlier. Okay I'm done blabbing....can anyone back me up?

well said

[911]

peace my brothers:D i also don't think it is the pipes. all slip ons ar almost exactly the same+or- 1/2 hp and thats not going to make this kind of dif. do this ;) the next time you race bring bolth quads to the rev limiter in 2nd to start ( sounds nuts but i took 6 hole shots this year) (lean forward ) this will take out the rider equation or to be a little less nutty take the quads onto the street if it is the clutch it will def. slip when bangin through the gears on pavement;) be sure to switch quads so you have a comparison good luck:devil:

[450 Racer R]

the difference would be in the head pipe wouldn't it? That's what I'm thinking. I thought the pro circuit was a full exhaust?

[450ar]

When i jetted my 450 i check to see what jett their was supposed to be in there. I had differnt jets. The main was a 120 and the needle was differnt too. i dont rember what it was.

[culookn]

what about tire size, i had on 18in razrs on my 450 and my cousin had factory tires on his 450 and he blew me away in a drag race since the 18's spn more at higher rpms?

[sulnz450r]

Are they geared the same ??:confused:

[brandonpeake]

if its a slip on and a full i think its the pipes as well

[challett3]

Both pipes are slip ons

Gearing is the same 14t

[jeepeater347]

I would think its something with the carb

[speedfreaksguy]

I'll bet one is black and one is red. The red 450's are faster. LOL

[challett3]

what about the carb do you think is wrong?

[BSTURDIVANT]

c Check to see if the carb is opening all the way-I've seen them come with too much slack in the cable and would only open 3/4 throttle!

[Kilabanshee]

Originally posted by BSTURDIVANT
c Check to see if the carb is opening all the way-I've seen them come with too much slack in the cable and would only open 3/4 throttle!
I had this happen on my 400ex awhile ago also make sure the sleve in your carb is really clean and the throttle camble Isn't to lose like Brent said. What tires are you guys running? One may have a better tread compound for whatever your racing in and has a slighter advantage or ones just lying about whats done to their quad other then that I'de think they would be in 1-2 lengths not 4-5....

[Johnny B]

are you running same fuel in both machines.