Do all 2 strokes somewhat splooge?

[mj4trax]

I'll be completely honest and admit that. . I don't know.

One thing that is completely new to me is the exhaust valve. It's a luxury I've never had before. (Can't believe how broad the powerband is on the bikes. ... I'm used to riding with such a narrow and peaky powerband on my quads .. . by comparison, it's just so easy to find power on the bike)

I haven't torn mine down yet but I'm going to before I ride it again. I was planning to index it and do some experimentation after I rebuild the top end. I'm an open book (or a sponge?) when it comes to the exhaust valve.

 

[whenfoxforks-ruled]

You can adjust when it hits in the power band. Vintage Bob

 

[mj4trax]

Yeah, I understand that, but I don't know where to index it to.

I assume that clockwise (tighter?) would make the powerband hit higher and harder and counter-clockwise (looser?) would make it more broad with less of a "hit"

As I bought the bike, motor-wise it is so much more there - honestly, it has more guts than an aftermarket 310 cylinder on the TRX - that I wouldn't know where to start to make it more powerful. I really have absolutely no complaints about the crispness or power output of this bike.. .. figure I need to get a lot more riding under my belt before it makes much difference to me. . . . especially since I ride woods, not mx ;-)

 

[whenfoxforks-ruled]

What is the ring life on that bike, 5~7 hours? Vintage Bob

 

[mj4trax]

okay. .. I see you'd rather throw an mx race spec at me (an admittedly novice trail rider) . . infer that I'm a lousy mechanic and that I ride the wrong bike for my conditions than actually answer a question directly.

I guess I deserve it for "hijacking" this thread as a newbie. .. . No hard feelings, but I'm done with this thread as I just don't need the aggravation. l8tr

 

[Brandon H.]

okay. .. I see you'd rather throw an mx race spec at me (an admittedly novice trail rider) . . infer that I'm a lousy mechanic and that I ride the wrong bike for my conditions than actually answer a question directly.

I guess I deserve it for "hijacking" this thread as a newbie. .. . No hard feelings, but I'm done with this thread as I just don't need the aggravation. l8tr

Nobody is trying to offend you, hey I am doing the same thing. I have a CR125, and I ride woods. Wrong bike for my setup but I like it, thats all that matters. These old dogs know a LOT, and just like to stress maintaince. We were all noobies at one point :cool: :nod:

 

[whenfoxforks-ruled]

No 4trax. Now do you understand why your bike spooges? I did not pull any of that information out of thin air. My 97 CR250 has a ring life of 5 hours. I do not ride like Millsaps! His ring life is more like 30 minutes plus 2 laps! There are a lot of jury rigs to make that bike more trail friendly, some arguably, like a flywheel weight. Most, I believe, just get used to the power, or are riding a worn out mx race bike. What is that quad of yours, a 4 stroke? Have you ever rode the 450 quads? They wear out a lot quicker. What do you want to do? Vintage Bob

 

[mj4trax]

rode a 450 quad a couple times. . .. wasn't impressed . .. at least as fast as my quad, but not half as fun to ride.

I'm digressing, but a brief history lesson on the Honda Fourtrax TRX250R is that it is a 250cc 2-stroke (non-pv) quad built from 1986-1989 . .. and it was about the only thing us quad guys had to race until '99. .. still dominated the races until the advent of the 450 production class. The motor is very similar to the ~'85 CR250 motor, but with a counter-balancer.

They have yet to make another quad that I would rather own. I am a two-stroke guy though and through.

I've had good reliability on my quads. . except for my first few years when I was really learning how to jet, and I leaned it out a couple times. Since then, I've learned a good "feel" for how I want my motors to run in order to get a good compromise of performance and reliability out of them. .. and the last 5-10 years has been very good for me. . . usually get about 50 hours out of rings. . . and get 3-4 ring cycles per piston/bore.

I honestly got into bikes because I wanted to see what it would be like to have a modern two-stroke engine. . . and it has been a good experience.

I did put a flywheel weight on the RM. .. and that has mainly just helped keep me from stalling as easily in the tight stuff. I really wouldn't call it a jury rig though.

Since buying my RM, I've got ~ 50-60 hours of trail riding on it (meaning that I should have changed the rings 10 times according to your service interval) and the motor has not experienced any compression or power loss, no change in the amount of slooge created and is not making any extra noises. I did buy a new piston/rings for it and will install before my next ride. If the splooge goes away from that alone. . . I'll be surprised, but happy.

The more I think about it, the more I believe/understand that the splooge is from my tendency to jet rich and the tight trails that I like to ride. I do tend to load it up a bit, but I have yet to actually foul a plug on the bike. It really does get much better when I can stay on the throttle for more than a split second in between trees and corners. I guess I'm saying that I'm comfortable with my understanding of splooge now. . . except that you were asking about the exhaust valve setting. Was that in connection with the splooge, or for a different reason?

 

[Rich Rohrich]

They have yet to make another quad that I would rather own. I am a two-stroke guy though and through.

Then you should head over to Service Honda for a little modern two-stroke quad goodness.

http://www.servicehonda.com/2010-models/honda/atv-srx250r

Honda-SRX250R



Service Honda 2010 SRX250R - Lighter more powerful and better handling version of the famous Honda TRX250R

2010 TRX250R Specifications

ENGINE
Engine Type 249cc liquid cooled single cylinder with power valve
Bore and Stroke 66.4mm X 72mm
Compression Ratio 8.5:1
Induction Six pedal reed valve
Carburetion 38mm Mikuni TMX flat slide
Ignition Solid state three dimensional map type digital ignition with electronic advance
DRIVE TRAIN
Transmission Close-ratio five-speed
Final Drive #520 o-ring chain
CHASSIS / SUSPENSION
Suspension (Standard) Front: Independent double wishbone with Showa shocks, five position spring preload adjustability 8.2 inches of travel
Rear: Pro-link fully adjustable single Showa Shock 9.1 inches of travel.
Suspension (optional) Front: Independent double wishbone with fully adjustable Ohlins Zero preload shocks with triple rate springs, 36mm pistons, external reservoir and 12 inches of travel
Rear: Pro-link fully adjustable single Ohlins Zero preload shock with triple rate springs, 46mm piston and remote reservoir and 12 inches of travel.
OTHER
Available Colors Red and Yellow
Model ID TRX250R

 

[mj4trax]

I guess I left out the srx. good catch. That is a quad that I would love to upgrade to. It's a lot of $$, but would be a great investment. . .. though that motor is still the '01 CR motor. .. so I don't know how much longer it can be called "modern"

Funny thing is that in my search to get a hold of something with a modern two-stroke motor, I found something that I enjoy riding more than my quad . .. in most situations. .. I don't have any plans to start selling quads off. .... yet. ;-)

 

[YZ__rider]

Fox Forks, I am curious what type of riding you do to rebuild every 5 hours. I had a YZ 250 back in the day that we rebuilt about every 40-50 hours. That thing ran like hell...those were good bikes.

Service Honda is the coolest thing since sliced bread, its too bad they are not within the average Joe's budget.

 

[mj4trax]

Service Honda is the coolest thing since sliced bread, its too bad they are not within the average Joe's budget.

I agree 100%.

I'll add that their parts are within that budget though. ... at least compared to the manufacturer's MSRPs ;-)

 

[whenfoxforks-ruled]

Fox Forks, I am curious what type of riding you do to rebuild every 5 hours. I had a YZ 250 back in the day that we rebuilt about every 40-50 hours. That thing ran like hell...those were good bikes.

Service Honda is the coolest thing since sliced bread, its too bad they are not within the average Joe's budget.

What, you think I own Service Honda or something? The book does not lie, nor is it after my wallet. If I could afford it, HELL YES it would get a fresh top end, and new tires every 5 hours! Its because I know that about the 5 hour mark, the ring is getting close to being out of spec. The power loss may even not be perceptible, except by monitoring with a compression gauge or tearing it down. Does not change the facts. I do not brag about my dirt bike abuse in the past, fast as hell though! Running plated bores long ruins the bore, the looser than normal piston pushes the softer material behind the plating. It looks good and slap it back together. Why does it run funny? The bore is oval. The steel liner shortens the ring life more, perfect. This is catastrophic maintenance, running past rebuild times, not preventive. 4trax, the flywheel weight, imo, puts abnormal stress on the crank and bearings, premature wear is possible. And its akin to dragging a small car engine around in back of your bike. De-tune the engine by lowering the compression and/or alter the porting. Air box and pipe/silencer can achieve safely slowing the engine down also. And the maintenance schedules can run longer! Basically turn it into a KDX/XR. Vintage Bob

 

[mj4trax]

Rings out of spec. .. only thing I can think of there is the end gap. I'll check that when I pull the cylinder apart on the bike, and make sure to share what I find.

On my quads, after running 50-70 hours on a set of rings, they are usually still in spec (though admittedly towards the high end of the tolerance) for ring gap, and that's with steel sleeves.

Detune by lowering the compression? You mean swapping bottom and mid end snap/response for a peakier, higher revving motor? That's what I've found every time I've run lower compression on my TRX motors. .. No thanks, that's the opposite of what I want.

Out of curiosity, how do you adjust the compression on stock o-ringed heads? On my o-ringed aftermarket TRX cylinder, I have interchangable domes with different squish volumes, and on my stock cylinders, I just adjust the head gasket thickness. . . or in some cases mill the head. I could see someone adjusing it though base gasket thickness. . . but then you're messing around with the port timing. I'm not planning to run anything but stock on my bike, but this is a curiosity for me.

Seems like an awful stretch to say that a 10 oz weight puts stress on the crank and bearings in the same order of magnitude that transmitting the piston stroke energy to the clutch basket could. .. and as far as stressing the bearings, that's a further stretch way unless it is out of balance or something. My flywheel weight is staying.

 

[whenfoxforks-ruled]

Not to worry, all the people with scary now devices in their bikes have clammed up for a while. They will be back. 4trax, I would not be using anything about a quad relative to a dirtbike. I was hoping you were going to tell me that the 450 quad was too fast. I have been by the quad sites before, no thanks. Misinformation and figuring runs a muck! They are different, and closer to car mechanics, not dirt bikes. All engine altering and replating goes to Forward Motion, what ever power you want where, if it can be done, he can do it. Vintage Bob

 

[mj4trax]

Ahh. . .. forward motion. ... I've sent a lot of cylinders there. . . but not lately. This may explain your short ring life description though. My TRX has a ring gap tolerance of .010-.020. Every cylinder I got back (by every. . . I mean somewhere in the 8-10 cylinders range) from forward motion started out between .018 and .019 on new rings . .. not long and they were out of spec. My rebuilt motors always made crazy knocking noises back then. I started going to GT thunder and Lukes Racing for my bores and have been starting out with ring gaps around .012. .. motors have been running better and lasting a lot longer since then. I am particularly careful not to cold-seize them though.

I am not trying to badmouth forward motion. Since all of the cylinders I got back were very consistently on that high side of the tolerance, there must be a reason or theory behind why. .. I just found that it didn't work particularly well for me. I'm sure the bike motors are a completely different story.

I think you are over-generalizing with regards to the quad websites. .. there are people out there who know what they're talking about. .. sometimes hard to find between all the others though.