Author Topic: Bike way too fuel efficent (Read 4513 times)

sangheraent · « **on:** June 23, 2014, 08:30:53 PM »

Ok last year I had a motor built by a small dune town shop. I got sucked in by the the talk. The motor is poor power still keeps with a yfz450 but the damn thing is super fuel efficient. The yfz will run out of fuel and I will still have 1/4 tank of fuel left. The bike also runs hot all the time. doing a plug shop shows it nice chocolate brown color and it runs perfectly.

I have never had a 2 stroke be so damn fuel efficient has anyone ever experienced this?

dammit spelt the title wrong.

pinned250r · « **Reply #1 on:** June 23, 2014, 08:50:23 PM »

Huh, that is actually pretty neat! I'd love that.... For my wife's bike lol. Low power blows, but I am curious what's going on, I go through atleast 2 tanks in the time my 4 stroke friends do. What's your set up? Fuel mix all the way to pipe.

Pumashine · « **Reply #2 on:** June 23, 2014, 08:54:55 PM »

You say the motor was built but did not say if any porting was done. A simple clean and match will still give the fuel efficiency of a stock motor just a bit more power as all we would like to have. The trx250r was a production motor. Some run better than others out of the jar. My sister and brother in law will not have any port-work done as they like to go out for hours at a time without refueling.

sangheraent · « **Reply #3 on:** June 23, 2014, 08:56:46 PM »

I bought a 6 pack rack because I thought my bike would chug gas. I couldn't believe it, my bike is a 4mm stroker with a 310 cylinder 72mm bore. The bike should be killing a stock yfz but it is not even winning just keeping up. but man rode for 4 hours on the meter burned only 1 jerry can.

rsss396 · « **Reply #4 on:** June 23, 2014, 08:58:09 PM »

A ported stock cylinder that can keep up with a yzf450 using less fuel means the porting guy did a good job!
The more efficient the cylinder the less fuel it needs, but just because something is more efficient does not mean its more powerful.

OK I see its a 310, still nothing against you but maybe you are not a great rider.

My nephew (my jockey on my Liger) just got back from the dunes with a bone stock yzf450 and not one stock quad beat him and he only had v shaped razr paddles on it.
I dont think the bike is fast all but the rider is and that could very well be the problem

sangheraent · « **Reply #5 on:** June 23, 2014, 09:02:44 PM »

This is not a stock cylinder my stock cylinder 261 LRD motor had more power then this one does. This is an LA sleeve 310 cylinder on a 4mm stroker crank. Shoot if my stock cylinder had this much power and used very little fuel it would be great.

rk88r · « **Reply #6 on:** June 23, 2014, 09:09:02 PM »

Have you tried givin' er a little more fuel?

rk88r · « **Reply #7 on:** June 23, 2014, 09:10:47 PM »

Maybe a little more fuel as it's coming on the pipe would help the power a little.

sangheraent · « **Reply #8 on:** June 23, 2014, 10:50:03 PM »

I have been riding for a very long time started at 8 I'm 27 now won several mx races and used to drag a banshee for fun. The only reason I can keep up with the stock yfzs is that I have them by a length and a half off the start. I didn't buy a drag motor I bought a motocross motor.

The lack of power shows its face when I'm going up a hill the bike needs to be brought almost down to first and full rev in every gear to do what it should do it 2nd-3rd medium throttle. also my bike will not pull 6th gear.

fearlessfred · « **Reply #9 on:** June 24, 2014, 12:02:18 AM »

is this a spacer plate motor and did they use a spacer plate to try and correct port timing because of the 4 plus crank,Im guessing low compression and lower port timing could cause this

broken1 · « **Reply #10 on:** June 24, 2014, 03:12:06 AM »

Maybe the tuning's off or some of the parts your using ain't working together very well. Maybe compression like fearlessfred said?

sangheraent · « **Reply #11 on:** June 24, 2014, 01:41:19 PM »

My personal feeling is that I got hosed by a builder that doesn't know his stuff and the parts are going against each other. I can't do a compression test for a couple of days but I will test that It runs on 110 doesn't like 100 very much and has decent torque before the pipe.

It is a spacer plate motor I am running brand new reeds Vforce 2s, sparks mx pipe, 39pwk, no air leaks anywhere cr250 ign, "custom cut domes". I am running everything exactly what the builder told me but now he is telling me strokers cant run cr250 ignitions and vf reeds are not good.

Bowtie316 · « **Reply #12 on:** June 24, 2014, 02:00:47 PM »

Do you have any other pipes to try?

JesseA420 · « **Reply #13 on:** June 24, 2014, 02:09:33 PM »

Quote from: sangheraent;37452

now he is telling me strokers cant run cr250 ignitions and vf reeds are not good.

all credibility is lost after that comment LOL. i would have someone credible check your port timings, something is off for sure.

pinned250r · « **Reply #14 on:** June 24, 2014, 03:14:56 PM »

Lol, aye aye aye... I'd get a refund. That's just poor.