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06 up 150f engine weight needed

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Always looking for the lightest possible engine options. So far my benchmark is a stroker XR200 engine at 58 lbs. It does all the right stuff with 6 speed and meaty power. The CRF230 is improved but with the addition of 10 lbs for e-start plus the weight of a battery. Pre-06 CRF150f kickstart engines are lighter but only 5 speed and weak kicker gears.

Now I've been teased by the news that the 06 and later gen 2 CRF150 has a substantially lighter engine even with e-start. I know these have fewer performance options but there is a 225 bore kit that makes decent power and torque.

Can anyone tell me the weight of an 06 or newer 150f engine? Please specify what it includes,.. oil,  shifter,.. sprocket,.. starter,.. carb etc.

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Well I don't have one anymore, was a 2007. Stock runs better than an 05~older 150f

 The cam cover it just a smooth aluminum cover similar to a CRF/XR 100. 5speed instead of 6.

Only a 24mm carb, so the carb would be used anyway, the sprocket and shifter would not be in the equation.

 My guesstimate for weight reduction is around 5 lbs. lighten the flywheel and crank another, lb.

Shorai battery 3 lbs. PWK carb is lighter than 230 carb. (Single throttle cable also)

 Even it you did not go crazy on the engine, just 225 kit, Match intake port to PWK carb, aftermarket cam, performance exhaust. Should be able to outrun an stock jetted, uncorked 230f

 

Add it all up, Should be at least 8-9 lbs lighter?

 

Icing on the cake:

250cc stroker crank.

 

Drawback 5spd

 

 

 

 

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Hmmm,.. 8-9 lbs lighter than an e-start 230 engine is still heavier than a 6 speed kickstart XR200 based engine.

I did find out what other Honda uses the 06 up 150 engine but in a kickstart version. XR150l but unfortunately its not sold in US.  I could probably get parts to delete the e-start? to shave another 8-9 lbs

xr150-l-cc-menu-honda.png

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Well if you wouldn't mind 40+ hp and insist on really light weight then its been done before right here in this forum... shoe horn in a CR250r engine.

No electric start on that one.

Still to heavy? Then and air cooled CR250r engine from the earlier 80's
Or how about an air cooled Cr480r?

Just shove a bunch of rubber fin dampers in the fins so it won't rattle so bad.

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Oh I don't mind excessive power,.. One of my other rides is a 130 hp two stroke (TZ750)

Seriously when I bring up ultralight bikes, two strokes immediately come up as a suggestion. I'll probably go there next but since I discovered how well light weight and torque go together, I want to push that combo as far as it can go.

I've actually included two strokes in my search for the ultimate simple lightweight engine. The two most promising candidates are a ktm200 and kdx200. They both evolved from 125's and are lighter than any engines born as a 250. The KTM is a little too "zingy" but could probably be tuned for more tractability. The KDX200 already has the right state of tune. In keeping with the theme of my bikes, I would probably choose an air cooled kdx for simplicity.

Its funny how my quest for a simple light engine always seem to lead me back to the 80's. The new engines make big power but at the expense of more weight and much more complexity. I would love to apply modern technology to improve older designs. Our air cooled engines could benefit greatly from modern plated bores and coatings for better heat transfer. I even looked at grafting an air cooled top end on a CRF250F bottom end to get a lighter more compact gearbox and eliminate water pump, hoses, radiators, brackets shrouds etc.... The problem is they all have such short strokes. Even a 450 has less stroke than our lowly 230's. 

Edited by woodsryder

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2 hours ago, 4strokeridertt said:

You should really stop looking so hard at the specs and go ride a nicely setup  late model KTM 300.

I don't know you but its hard not to read that as a bit condescending. I ride a 300exc fairly often.

In Michigan KTM 250/300 two strokes are the benchmark all good woods bikes are measured by. At about 225lbs no gas they are on the bottom end of the weight range for four strokes but not really that light for two strokes. Yeah,.. from what's available, they are hard to beat. I can still ride a respectable pace but after a day in deep Michigan or Florida sand I feel like I wrestled an alligator.

You should really try riding a well set up bike that's 45 lbs lighter,.. That's about two standard cement blocks. Pick up a couple at Home Depot and walk around with them for a few minutes to get my point. Take the engine, radiators and pipe out of your 300,.. now roll it around and imagine how much more fun it could be to ride at that weight.

Im not being a smart a$$, I've been riding a 180 lb bike for almost 4 years now and trust me it will make you wonder why the manufacturers can't do a lot better.

The answer is,.. because no one is asking for lighter bikes and no other manufacturer is offering one.  The Freeride is a big step in the right direction but it purposely has limited power and quite different handling to avoid being directly compared to their race bikes. Its not a stretch to see that KTM could drop a 300 cylinder on a freeride and alter the geometry to get the 300 down to 200 lbs with the exact same handling.

Heck, a 300exc motor in my chassis would weigh a good 5 lbs less than my bike weighs now or about 175 lbs. I just don't think its the best combo for me but it is possible.

Im not just obsessing over some trivial specs, a couple millimeters here or a couple lbs there. Well,.. I guess I am but that's the only way you can end up with a 45 lb weight savings over a bike you already thought was light enough. 

 

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I'm not certain about the accuracy of that shit, but is something like 57,5 lbs

20170506_165035.jpg

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Thanks, that looks like a pre 05 engine which is entirely different than 06 and later. However it is a good data point that I didn't have before.

It makes sense that this kickstart only version should be the same weight as an XR200 and it is only .5 lbs less. This could be the difference between 5 speeds and the 6 speed XR?

The 06 and later CRF150's are electric start with no kicker and are supposedly lighter? Some sources suggest that the basic motor is lighter but the e-start brings it back to about the same weight. That's what Im trying to verify

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1 hour ago, woodsryder said:

Thanks, that looks like a pre 05 engine which is entirely different than 06 and later. However it is a good data point that I didn't have before.

It makes sense that this kickstart only version should be the same weight as an XR200 and it is only .5 lbs less. This could be the difference between 5 speeds and the 6 speed XR?

The 06 and later CRF150's are electric start with no kicker and are supposedly lighter? 

Oh, I'm sorry! I didn't mentioned, this engine fits a 08 CG 150 (Brazil), I guess that is the same engine that fits the 06 and newest CRF150's.. The difference of weight between the two versions, electric and kick start is about 2 lbs. :thumbsup:

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Thanks, that looks like a pre 05 engine which is entirely different than 06 and later. However it is a good data point that I didn't have before. It makes sense that this kickstart only version should be the same weight as an XR200 and it is only .5 lbs less. This could be the difference between 5 speeds and the 6 speed XR?

The 06 and later CRF150's are electric start with no kicker and are supposedly lighter? Some sources suggest that the basic motor is lighter but the e-start brings it back to about the same weight. That's what Im trying to verify

 

 

Should be lighter than a 230f because:

 The valve cover is just that, a cover, that's not a rocker box that the rockers attach to.

+ the crank shaft is smaller OD because it has a lot less stroke.

AND it only has a 5speed.

 

It just makes sense that it's lighter.

 

 

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The 06 and up engines still have an upper engine mount, it just comes off the rear of the cyl head instead of the valve cover. I have read that it doesn't but looking at ebay pictures it clearly does. 5 speeds usually have wider gears so not much diff there. The e-start on the other hand adds a motor, reduction gears, starter clutch, solenoid, button and battery. Even with a $100 lithium battery and eliminating the weight of the kicker, shaft and gears the penalty for e-start is usually 8-10 lbs. 

At least I know that this engine can be fitted with kickstart using Brazilian parts. I'll start looking around for a good price on one.

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Sure, great, you got it figured out.

10 gears, spacers, shims, washers, clips are heavier than 12 of the same, any day..,

150f electric starter assemblies are much more robust and heavy than 223cc engines that have 16mm more stroke to turn over, goes with out saying.

Especially with the added drag of roller rocker arms on the cam, amazing the starter even turns over the 150f engine.

And why would the crank shaft on an 150f that has much less stroke than a 230, weigh more than a 230f crank? (Nothing is interchangeable on the two engines, except the carb, not even the header.

 

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Adnohguy,

Don't get worked up over this, I'm not doubting you. I appreciate your help and I agree it absolutely should be lighter than a 230 engine...  You just don't see where Im trying to go with this.  How much lighter matters a lot. The first sentence in this thread states that I am looking for something lighter than the 58 lb motor I'm using now. 

There are also reasons to avoid this engine such as 5 speed and lack of info and performance parts. I think the engine itself is indeed lighter for all the reasons you mentioned, but the e-start adds a lot back. I get your point that it has to be lighter than an e-start 230 which is great if that's your goal.

Right now the benchmark is my hybrid engine using XR200 6 speed cases with 230 crank, cyl and head. This offers all the hop up potential and weighs 58 lbs. Unfortunately its not a bolt together deal and requires machine work. I was hoping the e-start late model 150 might be close too the same weight, have decent power as a 225 and for those who want it,... e-start.

For my personal bike I was hoping to drop even more weight by converting it back to kickstart. Thanks to RND.23's post I now know for a fact it offers no weight savings over my hybrid motor. Thumpertalk comes through again!

Forums are a great place to get info but you have to have thick skin. Im a weight weenie so Im used to people getting impatient with me,.. they say, quit over thinking things,... go on a diet,... learn to ride,.. a couple pounds don't matter,.. get a better bike etc,.. Then they start another thread asking for weight reduction tips for their little red pigs, LOL!!

 

Edited by woodsryder

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I have a hybrid xr/atc/crf engine. You need to use a crf230L crank as the oil spinner end is the same as the xr and the f crank end is longer. I used a modified xr/atc cam so I could run the advancer and atc200x flywheel and electrics. The atc flywheel is much lighter than the xr one and can be lightened further as well. The crank taper has to be shortened for the atc flywheel and that is also a weight saving. Another way is to use a complete atc200x crank or xr200 crank with a 4 mm offset crank pin, an early crf150 cylinder with a CRF230 piston. Lighter crank, rod and cylinder.

 

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Thanks Grrenhuman I have followed some of your builds. I keep meaning to start another thread on hybrid engines but wanted to run this one a bunch first before bragging about it too much.

I did use a 230L crank not even knowing it was different from the F crank at the time. I shortened the left shaft as mentioned and used the smaller 150 flywheel. I used the 230 head vs XR for the bigger valves and mostly the ball bearing cam. Then the two options were to run a crank trigger ignition off the 150f flywheel, this requires a lot of fab work to the cover.,.. or use a modified cam to use the XR mechanical advance. I chose option three of course.. I added a bolt on trigger plate to the end of the 230 cam and relocated the stock 150f pickup in the head where the XR one was. It uses a double trigger because the cam spins at half speed. Now I can rotate the whole assembly to shift timing. Vary the width of the trigger and use the Pro Com CDI box.

One last critical mod was to modify and add the 230L primary gear to the XR clutch hub. This takes 20% of the load away from the clutch and gearbox. Hopefully,.. since the XR kickstart feeds through the cush drive and the more favorable 230 primary ratio, the kick mechanism will be happy. By contrast, the 150f kickstart does not go through the cush drive and often fails.

My one lingering concern is in regard to the notch in the rod big end to clear third gear. Powroll has been doing this for years but this notch was a but deeper. I allowed .025 clearance hoping its enough 

My XR200 Powroll stroker crank is at the end of its life and Terry hasn't been able to replicate the method they used to shorten the rods. If I can find a correct length rod and rebuild it, your idea of using the 150 cyl is worth looking at too.

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On ‎5‎/‎4‎/‎2017 at 4:06 PM, woodsryder said:

I don't know you but its hard not to read that as a bit condescending. I ride a 300exc fairly often.

In Michigan KTM 250/300 two strokes are the benchmark all good woods bikes are measured by. At about 225lbs no gas they are on the bottom end of the weight range for four strokes but not really that light for two strokes. Yeah,.. from what's available, they are hard to beat. I can still ride a respectable pace but after a day in deep Michigan or Florida sand I feel like I wrestled an alligator.

You should really try riding a well set up bike that's 45 lbs lighter,.. That's about two standard cement blocks. Pick up a couple at Home Depot and walk around with them for a few minutes to get my point. Take the engine, radiators and pipe out of your 300,.. now roll it around and imagine how much more fun it could be to ride at that weight.

Im not being a smart a$$, I've been riding a 180 lb bike for almost 4 years now and trust me it will make you wonder why the manufacturers can't do a lot better.

The answer is,.. because no one is asking for lighter bikes and no other manufacturer is offering one.  The Freeride is a big step in the right direction but it purposely has limited power and quite different handling to avoid being directly compared to their race bikes. Its not a stretch to see that KTM could drop a 300 cylinder on a freeride and alter the geometry to get the 300 down to 200 lbs with the exact same handling.

Heck, a 300exc motor in my chassis would weigh a good 5 lbs less than my bike weighs now or about 175 lbs. I just don't think its the best combo for me but it is possible.

Im not just obsessing over some trivial specs, a couple millimeters here or a couple lbs there. Well,.. I guess I am but that's the only way you can end up with a 45 lb weight savings over a bike you already thought was light enough. 

 

Sorry to appear condescending, I do not mean to be. We ride pretty much all year round and so do not have the long cold winter to spend building.

My oldest daughter rode a 150F with a 225 Engines Only built motor. It worked real well as the weight is down so low. She now rides a 300XC that I ride sometimes when I visit. Both bikes are an absolute blast, especially for someone small (300 is lowered a bit). But I have to admit that a 180 lb bike would be much more fun than something at 225 or more.

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3 hours ago, 4strokeridertt said:

Sorry to appear condescending, I do not mean to be. We ride pretty much all year round and so do not have the long cold winter to spend building.

Cool,.. I appreciate all input. The problem with typed words is that you don't get the gestures tone and mannerisms that would go with the spoken message. Its easy to read an attitude or vibe that you would never get in person. Happens to me too and when I go back and read it I can see how someone could take it wrong. This is one of the least antagonistic forums in that regard and with plenty of smart people willing to share info. :thumbsup:

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