Messages

2116

General Two Stroke Talk / Re: 2011 ETEC Bombardier engine..

« on: April 29, 2010, 07:29:50 AM »

Not only is the 800 2S much more powerful than the 1200 4S but it also gets better fuel economy, 19 mpg vs. 18 mpg. Imagine taking that 155 hp 800cc twin ,slicing off one cylinder, and building a 70 hp 6 speed dual sport! I think things are going to get VERY interesting in the near future.

2117

General Two Stroke Talk / Re: Husqvarna Creates New Stealth Bike

« on: April 28, 2010, 03:20:59 PM »

In one of these forums we have 250F's turning faster lap times then 450F's and a prototype SX350F winning - so much for the horsepower theory.

2118

General Two Stroke Talk / Re: Couple personal stories.

« on: April 28, 2010, 03:12:05 PM »

Back in the summer of 2006 I was doing some refit work for a company in my area and I got to know a guy working there. When he found out that I was an "offroader" he asked me for some advice about his son. Turns out his son had saved up money for a 250F, his mother making up the balance,bought a fairly new bike and three months down the road the rod snaps and cuts the motor in half.Gets a repair estimate for more than what they paid for the bike. The guy feels sorry for his son, lends him some more money and his son promptly buys another 250F. Rod snaps again and cuts the second motor in half. Now he has two dead fourstrokes and nothing to show for it and completely bewildered asks me what he should do? I advised him to buy either a SX250 or YZ250 two stroke and off they go to the bike shop to buy yet another motorcycle. They finally track down an SX250 (they were sold out) and the kid hasn't had a problem since - the bike has been "bullet proof".

What did we do with the 250Fs? I stuck chinese Lifan 200 engines in for the guy and he uses them for camplng bikes. So far the Lifans have stayed in one piece.
 
Oh and by the way,when they purchased the SX250 a family freind bought a 450F - which promptly blew!

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General Two Stroke Talk / Re: Husqvarna Creates New Stealth Bike

« on: April 27, 2010, 07:52:31 AM »

I don't have the actual figures but Husky sales are up significantly where as the "big four" have seen a decline in sales,some (Suzuki) more then others. With BMW's technical expertise and DEEP pockets I think we will see a dramatic resurgance of the brand. I'm not sold on the countershaft sprocket/swingarm fulcrum thing or the stacked transmission though, I think some things that are time tested and proven are still the best way to go. Norton first got the engine/swingarm placement correct and I suspect this is partly why David Knight couldn't come to terms with the BMW 450.

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General Two Stroke Talk / Re: Show us your ride.

« on: April 26, 2010, 07:38:31 PM »

Isn't that M-Star SC500 an 85? (Front disc brake).

2121

General Two Stroke Talk / Re: A Question for TMKIWI...

« on: April 17, 2010, 05:50:14 PM »

I've ridden TM 300's and found them to be "very Italion" in their handling characteristics - biased more towards straightline stability.As well,like the KTM 300, they are a case reed induction twostroke and seem to have a midrange bias, you won't get that "silky" feel to the powerspread that Maicos and older Honda CR250s have. They are limited production bikes with lots of cnc "eye candy" and their quality of construction make the japanese bikes look pretty ordinary.

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General Two Stroke Talk / Re: Dent in my pipe...

« on: April 17, 2010, 05:35:20 PM »

Be very careful when you use heat to blow that dent out of your pipe - heat + hydrocarbons + pressure = diesel engine.

2123

General Two Stroke Talk / Re: What Ever Happened To The 380?

« on: April 17, 2010, 05:29:10 PM »

I've got a 2003 Maico 380 Enduro (Kostler) and it is pretty much stock except for a W.E.R. steering damper and relocated footpegs.I've raced the bike and done very well in my age category (I haven't ridden the last three years - got hit BAD by a kid on a 520 KTM) and the 380 is an absolute hoot to ride.I understand they were discontinued because of crankshaft problems but mine has been reliable. I've since geared it down but I recall in one race flying down a wide open fireroad and I looked around and realized I must be going close to a 100 mph! That 380 is one of my alltime favorite motorcycles - they are that much fun.

2124

General Two Stroke Talk / Re: A knocking noise in my engine...

« on: April 17, 2010, 05:10:07 PM »

No,in your YZ engine, the crankshaft rotates in the cases in two roller (ball) bearings - one on either side. These are your crankshaft mainbearings.I'm starting to suspect this may be where your problem is.I've seen cases where the spacers that space the ball bearings in the bearing assy. have failed and the balls move randomly and jam.I've also worked on YZ 250s where the mainbearings have actually failed and siezed. The heat marks on your crankshaft can be from either the machining process to bore the crank halve for the conrod bigend pin or you've got a bigend bearing that is siezing.A careful examination of your big end needle bearing will reveal which is true.

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General Two Stroke Talk / Re: A knocking noise in my engine...

« on: April 17, 2010, 10:46:42 AM »

On the YZ250 the bigend of the conrod should be slotted and you should be able to see the individual needle bearings.If they are blue or "slanted" your rod is defective.Pay attention to the thrust washers on either side of the needle bearing,if they are "all chewed up" you know you have problems.If all this checks out O.K. pull your complete clutch assembly,including drive gear, off the motor to isolate the crank from the gearbox. Again try to rotate the crankshaft assy.,if it is still tight the you have a crankshaft mainbearing problem and the cases will have to be split. Were you riding at the Oregon sand dunes? I've done a few motors from this riding area and what seems to happen is that the crank mainbearings seize,welding themselves to the crankshaft and spinning in the aluminum cases.It's an ugly job to repair.

2126

General Two Stroke Talk / Re: A knocking noise in my engine...

« on: April 17, 2010, 08:12:46 AM »

I assume your bike is a YZ250 twostroke - hence no camshaft.When troubleshooting always start with the most basic ,check the rear skirt of your piston (pull the reedcage to view it),it has probaly broken off and fallen into your crankcase preventing full rotation of the crankshaft.Pull your magneto side cover off and try to rotate the engine by hand by moving the flywheel, if you feel tightness or play your conrod big end bearing is gone.If the problem is intermittant you may have a crankshaft main bearing problem, I've seen the ballbearing spacers fail and cause all kinds of strange problems.If the engine rotates freely by hand your problem lies in the primary drive/gearbox/kickstart area.

2127

Vintage Two Strokes / Re: Spring Ride of 2010

« on: April 13, 2010, 08:48:42 AM »

Nothing quite like a nice long trail ride to clear the cobwebs out of one's brains!I can remember many years ago I lost one of the rear axle nuts on my Husky during a cross country race and I crawled about a 1/2 mile down the trail (rolling out of the way every time I heard a bike coming) till I found it! After that I welded the one nut on one side and made sure the other side was VERY tight. 

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General Two Stroke Talk / Re: Education & Running costs

« on: April 12, 2010, 12:38:21 PM »

In the fall of 2004 I purchased a property near a lake.In the winter the lake freezes over and the snowmobile guys then race back and forth. The first few years I heard quite a few fourstroke sleds and then nothing but twostrokes untill this winter when I finally heard one (4s) again.To stay fit in the winter I also do a lot of cross country skiing and snowshoeing and same thing - I encounter only twostroke snowmobiles out on the trails.I'm not sure if the sales figures support me but in snowmobiling there seems to be a definate trend back to twostroke powerplants.

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General Two Stroke Talk / Re: Modern Bikes

« on: April 11, 2010, 05:05:43 PM »

A couple of years ago a friend of mine was part of a team that raced down in Baja and they won the 60+ category.Their times would have placed them in the top three in the 40+ category.At the time my friend was 67.

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General Two Stroke Talk / Re: Death to the four stroke!

« on: April 11, 2010, 04:46:56 PM »

File that under "Had a bad day!".He's lucky no one got hurt.