The 2002-2006 Yamaha SX Viper was a high-performance trail snowmobile that packed many advanced technologies. This model was virtually a de-tuned version of the high-end SRX 700cc triple. It was powered by a 696cc, 2-stroke, power-valved, single-piped triple engine that delivered 122hp in stock condition.
If you want to find out more about this classic Yamaha sled, this post is for you.
We at PowerSportsGuide have compiled all you need to know into this Yamaha SX Viper 700 review!
Yamaha SX Viper 700 Review
Yamaha SX Viper 700 Models
The SX Viper was part of Yamaha’s 700cc 2-stroke snowmobile breed, which included many great sleds like the VMAX SX 700, Mountain Max, SXR 700, and the high-end, triple-piped SRX 700.
The official name of the model was SX Viper, but due to its 700cc engine, it was commonly known as SX Viper 700.
Yamaha marketed this sled from 2002 through 2006 in many different configurations, including:
| Year | Model | Code |
| 2002 | SX VIPER | SXV700G |
| 2002 | SX VIPER ER | SXV700ERG |
| 2003 | SX VIPER ER | SXV70ERH |
| 2003 | SX Viper | SXV70H |
| 2003 | SX Viper Mountain | SXV70MH |
| 2004 | SX VIPER ER | SXV70ERJ |
| 2004 | SX VIPER Mountain | SXV70MJ |
| 2004 | SX VIPER S | SXV70SJ |
| 2005 | SX VIPER Mountain | SXV70MK |
| 2006 | SX VIPER Mountain | SXV70ML |
In a nutshell, the key differences between them were as follows:
- SX Viper: Designed for trail riding, the SX Viper was the base model in the ’02-’03 model years. It came with a shorter track, wider skis, and a manual start.
- SX Viper S: The (2004) successor of the base model, it was upgraded with a factory-installed belly pan protector and advanced Ohlins shocks.
- SX Viper ER: A more advanced trail model that came standard with an electric start and reverse.
- SX Viper Mountain: Designed for off-trail riding, the SX Viper Mountain featured a longer track, narrower skis, different suspension settings, and a manual start.
Let’s get down to the nitty-gritty and talk about these sleds in detail!
Yamaha SX Viper Engine
The Yamaha SX Viper was a high-performance trail sled, which was a less powerful configuration of the flagship SRX 700 triple.
These sleds shared the same 2-stroke, 696cc, power-valved parallel triple engine. But while the SRX 700 enjoyed a triple-pipe exhaust system and delivered 135-145hp, the single-piped SX Viper 700 cranked out 122hp at 8500 RPM and a peak torque of 76 lb-ft in the 7100-8200 RPM range, Snowmobile.com reports.
In terms of dimensions and specifications, the engines of these sleds were quite similar, but they had some major differences in their internals and exhaust.
Compared to the SRX, the Viper not only had a simpler and lighter single-pipe exhaust system, but it also featured a lighter crankshaft and pistons, and smaller exhaust ports.
As reported by Off-road.com, the rotating mass in the Viper engine was 1.5 pounds less than in the SRX.
To be more precise, the key features of the SX Viper 700 engine were as follows:
- Lightened powder metal forged pistons
- Lightened crankshaft
- One-piece cylinder head
- CNC-machnied exhaust ports
- Liquid-heated Mikuni TM33 flat slide carburetors (with T.P.S.)
- 300W DC-CDI ignition
- Self-cleaning electronic power valves
- NGK BR9ES spark plugs
- Forced air induction
- Automatic oil injection system
- New cylinder port timing
- Single-pipe exhaust system
- Electric start (on the ER model)
Although the Viper engine cranked out less horsepower than the triple-piped SRX 700, it was still more powerful than the non-power valved 700 engine.
The latter was commonly used in the less potent Yamaha sleds at that time including the Mountain Max 700, and the VMAX SX 700 trail sleds.
Yamaha SX Viper Chassis and Suspensions
The SX Viper shared its ProAction System chassis and suspension system with many other 2-stroke performance Yamaha sleds.
This rigid but lightweight chassis delivered industry-leading torsional rigidity and precise handling. You could expect the dry weight of the sled to be anywhere from 490-530 pounds depending on the model and year.
The key features of its front suspension systems included:
- Independent front suspension system
- Forged aluminum steering arms
- KYB gas shocks
- Travel: up to 9 inches
- Lightweight skis
At the rear you could find the innovative Yamaha ProAction SXV rear suspension system, of which its features were as follows:
- Type: Parallel rail slide suspension system
- KYB aluminum gas shocks
- Adjustable control rods
- Travel: up to 11.5 inches
Other features of the SX Viper 700 include:
- New hood design with large vents for increased airflow
- Factory belly pan protector (on the S model)
- New lightweight seat
- R1-style dual taillights and dual headlights
- Illuminated seat storage
- Illuminated engine compartment
- Dual-piston hydraulic brakes
- LCD gauge (borrowed from the R1 motorcycle)
- And more
Yamaha SX Viper 700 Riding Experience
The SX Viper 700 built its reputation on its high performance and sharp handling. So, it was no surprise that the model became widely popular among performance-minded sledders.
Its top speed was 105 mph on GPS under ideal conditions, which showed roughly 115-117 mph on the speedo. Yes, the speedometer of these sleds was very inaccurate.
The high performance of the Viper was accompanied by the sweet exhaust sound of its three-cylinder engine. For even better music and some extra HP, many owners replaced its single-pipe exhaust with a triple-pipe configuration.
In the corners, the SX Viper had awesome handling thanks to its rigid frame and suspensions. In return, it offered significantly less comfort than long-travel suspension models like the VMAX 700 Deluxe.
In terms of fuel economy, the SX Viper got roughly 14-16 mpg on the trails, which was considered to be relatively good in the 700 class.
Yamaha SX Viper Problems
The SX Viper was known as one of the most durable and reliable 2-stroke sleds in Yamaha’s fleet. Believe it or not, many of these hit 10,000+ miles without an engine refresh or repair!
On the other hand, this machine had some minor problems. Without claiming to be complete, they were as follows:
Weak W-arm: The rear suspension swing arm (a.k.a. “W-arm”) was prone to cracking on these sleds. It could be easily fixed by strengthening the arm by welding guests or replacing it with a heavy-duty aftermarket unit.
Not-the-best suspensions: Although the SX Viper 700 featured an advanced suspension system, it was quite stiff and couldn’t keep up with competitor models.
Waterpump seal: Keeping satey in mind, the waterpump seal of the Viper had to be replaced every 5,000 miles.
Oil lines: To prevent malfunction in the lubrication system (and engine seizure)the oil lines of the SX Viper had to be replaced periodically.
Electrical issues: The wiring harness under the engine was prone to rubbing through, which resulted in various electrical problems. Fortunately, it was an easy fix since wrapping this harness into a convolute tube permanently solved the problem.
High-maintenance power valves: Even though they were advertised as “self-cleaning” power valves, the exhaust valves of the SX Viper had to be manually maintained and cleaned. This meant a bit of extra maintenance over the non-power valved engines.
Yamaha SX Viper 700 Specs Chart
For your convenience, we’ve listed the key specifications of the 2002 SX Viper 700 in these charts.
(Note that this sled was manufactured for many years, and the specifications may be different in other model years.)
Yamaha SX Viper 700 Dimensions and Capacities
| Dimensions | 2002 SX Viper |
| Length | 2780 mm (109.4 in) |
| Width | 1200 mm (47.2 in) |
| Height | 1230 mm (48.4 in) |
| Ski Tread | 1070 mm (42.1 in) |
| Dry Weight (SXV70) | 222 kg (489 lb.) |
| Dry Weight (SXV70ER) | 235 kg (518 lb.) |
| Fuel Tank Capacity | 44.3 L (11.7 US gal) |
| Oil Tank Capacity | 3.0 L (3.2 US qt) |
Yamaha SX Viper 700 Engine Specs
| Engine Specs | 2002 SX Viper |
| Engine type | Liquid-cooled, 2-stroke, 7-port |
| Cylinder Arrangement | Parallel, 3-cylinder |
| Engine stroke | 2 |
| Cooling system | Liquid-cooled |
| Bore x Stroke | 2.72 x 2.44 in (69.0 x 62.0 mm) |
| Displacement | 696cc |
| Idle Speed | 1800 +/- 100 r/min |
| Carburetor | Mikuni TM33 x 3 |
| Engine oil type | YAMALUBE 2-cycle oil |
| Throttle Operation | Handle lever, right-hand operated |
| Fuel type | Unleaded gasoline. Pump octane (R+M)/2; 88 Or Min. research octane: 93 |
| Starting system (SXV70) | Manual with recoil starter |
| Starting system (SXV70ER) | Electric and manual with recoil starter |
Yamaha SX Viper 700 Track
| Track Features | 2002 SX Viper |
| Track | Molded rubber, fiberglass rod reinforced |
| Length on ground | 29.6 in (752mm) |
| Width | 15.0 in (381mm) |
| Track deflection | 0.98-1.18 in (25-30mm) / 10 kg {22lbs} |
| Drive Sprocket | Quadruple polyethylene, 9 teeth |
| Suspension type | Slide rail suspension |
Yamaha SX Viper 700 Transmission
| Transmission | 2002 SX Viper |
| Primary reduction system | Belt |
| Primary reduction ratio | 3.8:1-1:1 |
| Type | Automatic centrifugal engagement, infinitely variable |
| Drive | Silent chain enclosed in oil bath |
| Secondary Reduction Ratio | 1.73 (38/22) |
Yamaha SX Viper 700 Electric Features
| Electric Features | 2002 SX Viper |
| Ignition system | DC-CDI |
| Spark plug type | BR9ES (NGK) |
| Spark plug gap | 0.028 – 0.031 in (0.7 – 0.8 mm) |
| Battery Capacity | GM18Z-3A/12 V 20 Ah |
| Battery Maximum Charge Rate | 2.0 Amperes/hp for 10 hrs |
| Headlight | 12 V, 60/55 W x 2 |
| Tail/brake light | 12 V, 5/21 W x 2 |
| Meter light | 14 V, 50 mA x 6 |
| Indicator light | 14 V, 80 mA x 2 |
These charts are for informational purposes only! For exact specifications, please refer to the factory manual.
Yamaha SX Viper 700 For Sale
Interestingly, there are still many SX Vipers running out there.
If you are considering buying one, you may find some used Yamaha SX Viper 700s for sale on Craigslist, eBay, Kijiji, or snowmobile classified sites.
Also, it’s recommended that you visit Yamaha snowmobile forums and Facebook groups.
Takeaway – FAQs About the Yamaha SX Viper 700
What year did the Yamaha SX Viper 700 come out?
Yamaha introduced the SX Viper for the 2002 model year.
What years was the Yamaha SX Viper 700 made?
The Yamaha SX Viper 700 was marketed from 2002 to 2006.
What size was a Yamaha SX Viper 700?
The (2002) Yamaha SX Viper 700 was 109.4 inches long, 47.2 inches wide, and 48.4 inches high.
What was the track size of the Yamaha SX Viper 700?
The track of the Yamaha SX Viper 700 was 15 inches wide, while its length on the ground was 29.6 inches.
How much did a Yamaha SX Viper 700 weigh?
The Yamaha SX Viper 700 ER weighed 480-530 pounds depending on the model and the year.
What kind of engine was in a Yamaha SX Viper 700?
The power source of the SX Viper 700 was a liquid-cooled, 2-stroke, power-valved, 698cc, triple-cylinder, single-piped engine.
How much horsepower did a Yamaha SX Viper 700 have?
The engine of the Yamaha SX Viper 700 produced 122 hp out of the box.
How fast did a Yamaha SX Viper 700 go?
The top speed of the Yamaha SX Viper 700 was about 115-117 mph on the speedo, or 105 mph on GPS.
Was the Yamaha SX Viper 700 a 2-stroke?
The Yamaha SX Viper 700 was powered by a 2-stroke engine.
Did the Yamaha SX Viper 700 Have a Reverse?
The SX Viper 700 ER came standard with a reverse system, while the rest of the Viper line lacked this important feature.
Did the Yamaha SX Viper 700 Have an Electric Start?
The SX Viper 600 ER came standard with an electric start, while its siblings featured manual start.
How Much Oil Did a Yamaha SX Viper 700 Hold?
The SX Viper 700 had an automatic oil injection system featuring a 3.2-quart reservoir.
How Much Fuel Did a Yamaha SX Viper 700 Hold?
The fuel capacity of the SX Viper 700 was 11.7 US gallons.
How Much Does a Yamaha SX Viper 700 Cost?
The asking price of a used SX Viper 700 averages between $1,000 and $5,000 depending on the year and condition.
References:
