Author Topic: Puke tube questions  (Read 580 times)

c3powil

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Puke tube questions
« on: August 30, 2017, 09:09:27 AM »
By my readings on this forum, it seems I shouldn't have to empty the puke tube as often as I am.

It seems every time I go on a ride, even a ten or fifteen minutes trip, I'm sure to find a full tube that needs to he dumped. If I don't dump it, it drops on the pavement in my driveway over a few hours and I'm left with a horrible oil stain.

To my understanding, the puke tube is just a drain/vent for the crankcase to get rid of extra oil and condensation.

Does this mean my oil was just overfilled and now the engine is blowing it out? I haven't changed the oil since I picked it up from the dealership last week. It was pre-owned with 1800 miles.

ktran

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Re: Puke tube questions
« Reply #1 on: August 30, 2017, 09:51:14 AM »
My puke tube fills up really fast if I'm running high RPM. It shouldn't fill up very fast with normal city riding.

Check your oil level with the bike on the centre stand. Overfilling oil can cause the puke tube to fill up quickly, as can low engine compression. But for me it's only an issue if I'm running high speeds on the freeway.


By my readings on this forum, it seems I shouldn't have to empty the puke tube as often as I am.

It seems every time I go on a ride, even a ten or fifteen minutes trip, I'm sure to find a full tube that needs to he dumped. If I don't dump it, it drops on the pavement in my driveway over a few hours and I'm left with a horrible oil stain.

To my understanding, the puke tube is just a drain/vent for the crankcase to get rid of extra oil and condensation.

Does this mean my oil was just overfilled and now the engine is blowing it out? I haven't changed the oil since I picked it up from the dealership last week. It was pre-owned with 1800 miles.

c3powil

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Re: Puke tube questions
« Reply #2 on: August 30, 2017, 12:07:33 PM »
Well, I pretty much run high rpm everywhere I go. 8-9.5k is the happy spot for torque and HP.

Greyrider

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Re: Puke tube questions
« Reply #3 on: August 30, 2017, 02:57:08 PM »
I dont run my Wolf above 8000rpm very often, thus don't have to mess with my puke tube much. It IS fun to rev on occasion though...

ktran

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Re: Puke tube questions
« Reply #4 on: August 30, 2017, 11:57:43 PM »
Well, I pretty much run high rpm everywhere I go. 8-9.5k is the happy spot for torque and HP.

I like to rev high too. It's certainly fun to do especially when you're riding with lower-revving (but almost always more powerful) bikes.

However, I like to rev high and then shift, rather than try to sustain 8k+ RPM all the time. I do the occasional trip like that, trying to stay over 100-105 km/h, but I accept that the puke tube fills up really fast that way. Also you'll probably need to change your oil much more often than the recommended intervals (manual says every 3000 km, I change every 1200-1500).

I find the smooth, comfortable sweet spot to be around 6500 RPM, with my 17T/40T sprocket pair. 5000 RPM nets a tiny bit of mirror vibration as you get up higher, and 7000-7200 RPM is when I feel peak torque kicks in, and then it smoothes away somewhat by the time you reach 8000.

BeebBobE

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Re: Puke tube questions
« Reply #5 on: August 31, 2017, 06:02:20 AM »
i have not changed from stock to a 17T here, although the 17T is sitting here in a cabinet! :-\ I guess I have not felt the need to go to a sprocket with more teeth. I just peg it and WOT for extended periods if need be, since I rode home in the pouring rain for 4 hours from KC on the highway surrounded by tractor trailers! I just pegged it and felt like if it was gonna blow it would blow! To me the engines are designed to be ridden and they are air cooled which makes them a bit different than a water cooled engine. The design characteristics between water cooled and air cooled engines are made to run under different conditions, fin design to cool the engine has to have air moving past and between the fins! You stand more of a chance blowing up an air cooled engine sitting in traffic not moving or revving an engine while not moving can heat an air cooled engine up extremely fast can also cause it to blow! Be mindful of this when sitting for long periods in traffic on a hot day. I will admit I loved my  1974 Moto Guzzi Eldo and batwing fairing in winter, warm air flowing past the heads kept my legs warm in winter on the highways in Dallas Tx and this was also true of my 1977 Honda 750 four. Hope this helps in contributing to some of the newer riders understanding on these engines. I will also say that in heavy traffic that is backed up on a freeway there was always a need to keep the engine moving , hence many times splitting lanes or moving to the shoulder to go around traffic that was at a standstill. If you did not keep that engine with cooler air circulating the fins, you could easily blow the engine in traffic and lose your motor and hence your ride!
« Last Edit: August 31, 2017, 06:07:11 AM by BeebBobE »
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c3powil

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Re: Puke tube questions
« Reply #6 on: August 31, 2017, 04:27:01 PM »
I like to stay above 6k and between 8 and 10k most of the time. Ill shift at redline and cruise around 8k. It's kind of annying if I have to empty the tube after a 10 minute highway run. It will sustain 65mph for long periods, and that's running the bike at 8k rpm...

c3powil

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Re: Puke tube questions
« Reply #7 on: September 04, 2017, 07:42:02 AM »
Update

I'm fairly sure it was just a case of too much oil. At first I was emptying the tube every ride, and it was pure oil coming out. This morning after my ride to work, on and off highway, the tube was only 1/5 full, and it was a light tan color liquid.

Oil is still full.

Papa Bear

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Re: Puke tube questions
« Reply #8 on: September 04, 2017, 04:23:31 PM »
Why do you think the bike had too much oil in it before? Who would have overfilled it?
Get your motor runnin' .. get out on the highway.

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ktran

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Re: Puke tube questions
« Reply #9 on: September 05, 2017, 01:46:35 PM »
You might want to check your oil now...

The puke tube does fill faster when your oil level is higher, but I've found that it's really most reliably a result of high RPM running.

Some notes on that, while we're at it:

If the specs are to be believed, max RPM is at 8500, but max torque physically cannot be at 9000 RPM, higher than max RPM. It's just not possible. I don't have access to a dyno, but my best guess from feel is that max torque kicks in around 6500-7500, somehwere. Any faster and you're just spinning without pull. You can accelerate if you have wind and terrain working for you, but you're "running out of breath" if either or both are working against you.

Now, if you're on the freeway or other high speed road, there's really no choice, but it's not a great idea to run high RPM all of the time. For one, you're out of the RPM range where you have any substantial pull if you need to accelerate. Secondly, you're getting close to that 9500 rpm redline. Higher revs will lead to faster parts wear and oil breakdown. There's just no way around that.

All that said, I love revving my little bike, and will often hit above 8.5k RPM to shift if I'm feeling spirited, or if I'm riding along with more powerful bikes, but for cruising, it's really, really much more comfortable to keep it lower.

Update

I'm fairly sure it was just a case of too much oil. At first I was emptying the tube every ride, and it was pure oil coming out. This morning after my ride to work, on and off highway, the tube was only 1/5 full, and it was a light tan color liquid.

Oil is still full.

c3powil

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Re: Puke tube questions
« Reply #10 on: September 05, 2017, 08:35:33 PM »
Think it probably had too much oil in it from the PO. I called the dealership and asked, but they didn't change the oil while they had it. The PO probably topped it off before the trade in and added a few too many cc.

Do you check oil while cold or warm?

Papa Bear

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Re: Puke tube questions
« Reply #11 on: September 06, 2017, 05:19:39 AM »
Cold on flat terrain.
Get your motor runnin' .. get out on the highway.

Check out http://www.hogsforhospice.com/

BeebBobE

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Re: Puke tube questions
« Reply #12 on: September 06, 2017, 06:01:03 AM »
  :o dimwit that i am, i guess i don't pay much attention to rpm's and just ride! :P  i might test out the 17 T just to see what it does, but i have gravel drive of about 1,000 feet that i go down and really don't want the chance of jamming a rock in between the sprocket and housing! It might be nicer on long rides to have a lower rev engine, oh well, i did get the sprocket to try it out and haven't bothered with it as of yet. Honestly, i just ride it and like its gearing in traffic. Once the bugs are worked out of it, it's a "sweet little" machine!  Have ya seen the new CSC Motorcycles Zongshen Cafe style 250?
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Papa Bear

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Re: Puke tube questions
« Reply #13 on: September 06, 2017, 06:23:31 AM »
You will love the 17 tooth gear as many do here.
I went even further and changed the rear from 40 to 35 tooth (kept the 16 up front).
I sometimes wish I had kept the 17 I had and use it with the 35 rear .....

Get your motor runnin' .. get out on the highway.

Check out http://www.hogsforhospice.com/

c3powil

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Re: Puke tube questions
« Reply #14 on: September 06, 2017, 05:52:49 PM »
I checked the oil on flat ground, center stand, cold enough that I could hold my hand against the engine case.
The oil was full!

I believe I will be getting less and less puke as the oil level continues to even out. However, I WILL change the oil soon. I have no idea how old the oil is, and even if the PO added oil before he traded it in, I'm not even sure when that was.

I am considering the 17t sprocket upgrade, as well. Is there any noticeable loss in torque or pull with that upgrade? What rpm are you guys pulling at around 65mph? I seem to be around 8.5k, and it gets close to 9+k if i'm going downhill around 75mph.

I do a short 5-10 mile run on the highway on my commute, and I'd like to keep the rpm down.