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Old 12-17-2012, 09:32 PM   #14011
ferretface
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Question Riding at altitude

I'm currently riding at around 2500-3000m and have noticed the lack of power (even worse when running high octane fuel) and I was wondered if anyone has tried any quick fixes to make it run better without messing around with re-jetting?

Another guy on a KLR650 has been riding along with me and the "altitude sickness" doesn't appear to affect the Kwakas as much. Maybe something to do with the vacuum type carb on the Transalp - not really sure......

It's okay to re-jet for long term use but I won't be riding at altitude all the time so I need another solution.

I'm going to be heading to higher altitude soon and was thinking of drilling some holes in the airbox (airfilter side) and sticking some rubber grommets in the holes and unplugging them when the bike starts to struggle for air.

Maybe someone on here has another idea or suggestion before I start making holes in the airbox?

Cheers
Dan
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Old 12-17-2012, 11:30 PM   #14012
2bold2getold
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Quote:
Originally Posted by ferretface View Post
I'm currently riding at around 2500-3000m and have noticed the lack of power (even worse when running high octane fuel# and I was wondered if anyone has tried any quick fixes to make it run better without messing around with re-jetting?

Another guy on a KLR650 has been riding along with me and the "altitude sickness" doesn't appear to affect the Kwakas as much. Maybe something to do with the vacuum type carb on the Transalp - not really sure......

It's okay to re-jet for long term use but I won't be riding at altitude all the time so I need another solution.

I'm going to be heading to higher altitude soon and was thinking of drilling some holes in the airbox #airfilter side# and sticking some rubber grommets in the holes and unplugging them when the bike starts to struggle for air.

Maybe someone on here has another idea or suggestion before I start making holes in the airbox?

Cheers
Dan
From my experience in trips to CO mountains ( 8k ft - 13k ft ) every summer for 30+ yrs. In the 70s and 80s on the old trials and enduro bikes, carbs required dropping the main jet size quite a bit. With the newer bikes with the CV (vacuum) carbs not so much. Each bike is different...KLX300 with CV carb needed a much smaller main jet. Don't remember exactly how much but was supprised how much it took. KLR with CV carb needed very little reduction, 150 to 148. DR350 with CV carb none. And really ran great. All had "opened" air boxes. XR650R with non CV carb went from 150 to 125 main. Don't know how much air box mod will help. You could lean idle fuel screw ( turn in ), might help idle but probably won't effect mid and high rpms much. Some people have reported no problems at altitude. I haven't had my TA up there yet ( next summer ), so I'm also interested to hear what jetting and mods the Colorado TA guys are running. If you're not getting knock or hot running, lower octain gas might help. Hard to tell with the alcohol blend gas we have now. Try to find non blend gas. Makes 3 to 5 mpg difference in my car. Not much way around some loss of power though, short of a turbo.
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Old 12-18-2012, 03:28 AM   #14013
mas335
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Have you checked your air filter lately, is it dirty? Rather than modifiy the air box you might try a less restricted air filter element. I'm not a big fan of K&N filters but that might help or better yet do the "Ladder" air filter mod that has been discussed in the past.

Without going into details you basically remove all the paper from the filter frame and replace it with a UNI filter or like I did replace it with the foam element from a NX125 filter. It will breath much easier.

The mod is not something that you can easily do, especially without a dremel tool but you only need to modify the filter frame once and then you have a washable foam filter.

See post 11484-11490 http://www.advrider.com/forums/showt...r#post16069437
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Old 12-18-2012, 04:55 AM   #14014
partireper.it
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This is my transalp by the way:
link: http://www.partireper.it/wp-content/...e-metzeler.jpg

if you are looknig for second hand original transalp parts I have them listed onto this page:

http://www.partireper.it/ricambi-usati-honda-transalp/
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partireper.it screwed with this post 12-18-2012 at 01:37 PM Reason: resizing my image
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Old 12-18-2012, 11:19 AM   #14015
ric678
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xxxxxxxxxxxxxtra large pic

Holy Hell, could that pic be any bigger!!
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Old 12-18-2012, 08:10 PM   #14016
mgorman
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Quote:
Originally Posted by ferretface View Post
I'm currently riding at around 2500-3000m and have noticed the lack of power (even worse when running high octane fuel) and I was wondered if anyone has tried any quick fixes to make it run better without messing around with re-jetting?

Cheers
Dan
I had always heard the CV's weren't as finicky as normal carbs but I've never
been above 7000 feet to know the difference. Has the slide ever been drilled? Some people drill the slides with a slightly larger hole to aide in throttle response and performance. I wonder if too big of a hole may have been drilled that would cause the slide to not have enough vaccume to raise it?

From what I understood is Octane resists predetonation and helps high compression motors run cooler. So, I took some premium gas, 93 and a can of 87. Rode the XR with the cheap stuff, drained it and put in the good stuff then back to the cheap stuff. The bike ran better on the cheap stuff. If it had been a high compression motor, it could damage it but the XR and my '89 TA are far from that.

If it weren't such a pain to drain the TA tank, I'd try it on that bike too.
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Old 12-19-2012, 08:58 PM   #14017
ferretface
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Quote:
Originally Posted by 2bold2getold View Post
From my experience in trips to CO mountains ( 8k ft - 13k ft ) every summer for 30+ yrs. In the 70s and 80s on the old trials and enduro bikes, carbs required dropping the main jet size quite a bit. With the newer bikes with the CV (vacuum) carbs not so much. Each bike is different...KLX300 with CV carb needed a much smaller main jet. Don't remember exactly how much but was supprised how much it took. KLR with CV carb needed very little reduction, 150 to 148. DR350 with CV carb none. And really ran great. All had "opened" air boxes. XR650R with non CV carb went from 150 to 125 main. Don't know how much air box mod will help. You could lean idle fuel screw ( turn in ), might help idle but probably won't effect mid and high rpms much. Some people have reported no problems at altitude. I haven't had my TA up there yet ( next summer ), so I'm also interested to hear what jetting and mods the Colorado TA guys are running. If you're not getting knock or hot running, lower octain gas might help. Hard to tell with the alcohol blend gas we have now. Try to find non blend gas. Makes 3 to 5 mpg difference in my car. Not much way around some loss of power though, short of a turbo.
I haven't played with the mixture but think it is running quite lean already as I get around 50mpg with pillion and full luggage. Might be worth looking at though! I'm in South America at the moment so god knows what blend the TA is getting. When we rode through Colorado, I always used the lowest octane available - think it might have been 83/85 but seemed to run fine.

Quote:
Originally Posted by mas335 View Post
Have you checked your air filter lately, is it dirty? Rather than modifiy the air box you might try a less restricted air filter element. I'm not a big fan of K&N filters but that might help or better yet do the "Ladder" air filter mod that has been discussed in the past.

Without going into details you basically remove all the paper from the filter frame and replace it with a UNI filter or like I did replace it with the foam element from a NX125 filter. It will breath much easier.

The mod is not something that you can easily do, especially without a dremel tool but you only need to modify the filter frame once and then you have a washable foam filter.

See post 11484-11490 http://www.advrider.com/forums/showt...r#post16069437
I'm not a fan of K&N either but I like the idea of the foam filter mod. I'll see if I can source the bits required and report back. Thanks for the link!

Quote:
Originally Posted by mgorman View Post
I had always heard the CV's weren't as finicky as normal carbs but I've never
been above 7000 feet to know the difference. Has the slide ever been drilled? Some people drill the slides with a slightly larger hole to aide in throttle response and performance. I wonder if too big of a hole may have been drilled that would cause the slide to not have enough vaccume to raise it?

If it weren't such a pain to drain the TA tank, I'd try it on that bike too.
I've got a set of carbs from a '93 Transalp but I am using the vacuum sliders from the original '87 carb which are made of plastic instead of metal so maybe that has something to do with it. I don't think it has been modified apart from that though.
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Old 12-23-2012, 06:45 PM   #14018
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Resouce paper update and my build begins...

Before I get into my build, I wanted to update everyone on the resource guide that I said I was putting together from this thread. The paper is together and is now being reviewed by several folks from the forum whose input we all appreciate. As it stands now it is over 400 pages (text and pictures). My plan is to post it up as a PDF file for folks to download. Additionally, I view the paper as a "GROUP WORK IN PROGRESS" and anyone who would like to add write ups to the paper, to please send me their input (with pictures) and it will be added.

One of the biggest issues I found in putting this together is when ADVRider updated how pictures are handled, we lost a major amount of data when the earlier pictures that were hosted on the site server were deleted. Additionally, where noted I have indicated who posted the information that is quoted in the paper. If you find that you want to change, update or correct anything that is listed, please send me your updates and we will get it posted.

I realize that until you see the paper there is not much to add... My plan is as soon as I have the reviewers comments I will get it up for everyone!


Now, onto my build...

I picked 89 Honda Transalp earlier this year from Seattle Used Bikes as my friend owns this shop and he new I had been looking for one of these for years. There are a lot of dual sport rides that I have had on the back burner for years and with the rebuild of this bike I am hoping to achieve many of them.



Well, the bike when I put it in the studio it was running great, but with any bike that is 24 years old there is only so much trust you can put in seemingly good looking parts. After two months of ordering parts and pieces both from US suppliers and European vendors, I can finally begin the tear down on the bike. A major thanks for parts and pieces that are almost impossible to find go to my friends MAS336 and LADDER106. Mark and Ray are very much a part of this build as are many of you. Your input over the last 9 years has built a wonderful resource for anyone wanting to build one of these bikes...





To date I have been able to do the following: Suspension upgraded: front forks are from an XR650 (rebuilt) and the rear shock is an XR250 with the spring upgraded to Spring rate: 11.5kg / mm. This will place the bike seat at just under 41" which is exactly what I wanted. Front and rear wheels are completely rebuilt, rear brake converted from push to pull (thanks Locorider!) that was a great idea. If you are sticking with drum brakes, this is one of the simplest mods to protect your rear linkage. The drum brake cam works exactly the same in either the push or pull configuration so all you have to do is move the lever.

Something else I was able to do tonight was the blending of a XR450 rear fender. The previous owner for some reason sawed off the end of the fender leaving the bike with little rear wheel protection. Since I decided to go with a high mount fender, I was able to order all the plastics for an XR450 from EBay for $20.00 and when I started looking at the fender I found that cutting at the bolt hole location gives you a fender that can be slipped onto the existing TA fender and be attached (I will post pics on that as well). With everything, as I progress I will add more images.

Other areas that I will be replacing or upgrading are:
Carbs rebuilt (new diaphragms in hand as well as the slow 40 jet upgrade)
Clutch rebuild
Air box upgraded (Rays mod)
Engine mounts upgraded (Rays mod)
Top end rebuilt
Rays optical fuel gauge
All electrical connection cleaned and upgraded
Swing arm stripped, coated and bearings replaced
Brakes upgraded
New handle bar
Highway Dirt Bike guards (you need to see these things: http://www.highwaydirtbikes.com/HDB_Shop/index.php?app=ccp0&ns=prodshow&ref=billet_hg_7%2F8
Handle bar switches replaced
PIAA lights upgraded
XR450 high mount front fender
XR450 rear fender

It will probably take till the end of January to finish the build...funny how all the parts in bags make the build seem so far from the finish...but that's have the fun!

When I first started my build I wanted to do a TA to AT conversion, but than after some wonderful conversations with folks here I have found that what I really wanted was a blend.

As Robin said, of all the bikes I have built this one seems to multiply the number of parts as they come off.





In closing I want to wish every single person here a MERRY CHRISTMAS AND HAPPY NEW YEAR!

I consider myself lucky to have found this group and look forward to where the new year is going to take all of us!
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Old 12-23-2012, 08:21 PM   #14019
happyclam
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Dr. E . WOW! You make what i'm trying to do childsplay. Can't wait for your pdf file. My resurrected Ta is still coming along well.Yours looks better than mine before you started the build.I will ad pics...I promise, tried tonight but photobucket said it didn't know me.Mine was crashed and left for dead for 10 + years. So far...xrl complete front end, new tires, boiled carb twice, rebuilt/repaired back side of platics, alot of scrubbing/touchup, rear shock with modified spacer, and the list goes on.... I debated selling my vstrom to pay for a lot of well needed parts...but i love the wee too, modern reliable. I'll just have to be patient. Anyway, I had a question for you gurus. I did the 40 jet change, cause she took forever to warm up. Now my choke doesn't work right. I know it functions, just doesn't idle. I drilled out the pilots and have played with 1 turn out to 2.5 turns with everything in between. Still no easy start. Once warm up shes fine, just needs throttle to get her going a bit. I 've searched and searched.Is it because i didn't shim my needles? What does raising the needle do to the mixture? Thanks for any advice. The Myans were wrong, go figure.
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Old 12-23-2012, 08:47 PM   #14020
2bold2getold
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Quote:
Originally Posted by happyclam View Post
Dr. E . WOW! You make what i'm trying to do childsplay. Can't wait for your pdf file. My resurrected Ta is still coming along well.Yours looks better than mine before you started the build.I will ad pics...I promise, tried tonight but photobucket said it didn't know me.Mine was crashed and left for dead for 10 + years. So far...xrl complete front end, new tires, boiled carb twice, rebuilt/repaired back side of platics, alot of scrubbing/touchup, rear shock with modified spacer, and the list goes on.... I debated selling my vstrom to pay for a lot of well needed parts...but i love the wee too, modern reliable. I'll just have to be patient. Anyway, I had a question for you gurus. I did the 40 jet change, cause she took forever to warm up. Now my choke doesn't work right. I know it functions, just doesn't idle. I drilled out the pilots and have played with 1 turn out to 2.5 turns with everything in between. Still no easy start. Once warm up shes fine, just needs throttle to get her going a bit. I 've searched and searched.Is it because i didn't shim my needles? What does raising the needle do to the mixture? Thanks for any advice. The Myans were wrong, go figure.
If it set up for ten years it could have something really stopped up. But it sounds like you had it running. Check the idle air jets and be sure the choke plungers are closing all the way. Also check the sync on the carbs, and vacuum leaks. Mine idles best with the mixture/volume screws out ~ 4 turns out. Raising the needles shouldn't effect the idle much/any...makes coming on the mid range circuit a little richer. My carbs are 100% stock...runs perfect.

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Old 12-23-2012, 08:48 PM   #14021
Ladder106
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There's a lot going on in carbs so there are a lot of questions for you.

Quote:
Now my choke doesn't work right. I know it functions, just doesn't idle.
Can you be more specific here? What do you mean by "doesn't work right"? Do the choke slides move in and out of the carbs? Are the soft sealing ends of the choke plungers in good shape? Do the plungers move in and out of the carbs without binding? Are the plastic covers that thread into the carbs in good shape?

Does the bike start easier with the choke on? Once warmed up does activating the choke make the bike run so rich it slows the idle speed and eventually dies?....it should.

Quote:
I drilled out the pilots and have played with 1 turn out to 2.5 turns with everything in between.
I'm assuming you mean you drilled out the pilot mixture adjusting screw plugs and now have access to the screws. If you just did this does it mean that you "boiled" the carbs with those screws in place?

What does "boiled the carbs" actually mean?

OK..if you soaked the carbs or something with the pilot mixture adjusting screws in place, you likely did something nasty to the tiny O-rings that live at the end of those screws. Those screws, the small spring, small washer and tiny O-ring should be removed before soaking/boiling the carbs in anything.

These mixture screws fine tune the idle mixture of the carbs so if they are dirty, clogged or not sealing due to O-ring damage you will not be able to adjust idle mixture.

Correct idle mixture should be achieved with the screws set between 1/2 and 3 turns out. When turning the screws in do not bottom them hard into the carb body...they are small sensitive tapers.

When removing these screws from the carb for cleaning and inspection be careful. The screw will come out first, then a small spring, then a tiny washer and then a tiny O-ring. You may have to tap the carb on the bench to dislodge the washer and O-ring. The O-ring should not be flattened torn, stretched or partially dissolved by a carb-cleaning solution.

Quote:
What does raising the needle do to the mixture?
Raising the needles makes the mixture richer between 1/3 and 3/4 throttle...or there abouts. You should not have to change this in the TA unless you've done something radical to the airbox or exhaust.

Photos would be a huge help
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Old 12-23-2012, 08:51 PM   #14022
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2bold....

If your screws are 4 turns out, you should really consider larger pilot jets. 4 turns puts you in danger of having the screws fall right out of the carbs on a bumpy off-road ride. There's not much spring tension to help keep the screws in place with them backed out so far.

I'd try 40s first, then maybe 45s
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Old 12-23-2012, 08:54 PM   #14023
Ladder106
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Old 12-23-2012, 09:19 PM   #14024
2bold2getold
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Quote:
Originally Posted by Ladder106 View Post
2bold....

If your screws are 4 turns out, you should really consider larger pilot jets. 4 turns puts you in danger of having the screws fall right out of the carbs on a bumpy off-road ride. There's not much spring tension to help keep the screws in place with them backed out so far.

I'd try 40s first, then maybe 45s
Your right, and worse than that I've got big long screw extensions so I can reach in there behind the AT tank and adjust them without taking the tank off. But I did stretch the springs a little. Do it every time. I live at almost sea level but do a lot of my riding in NM and CO mountains and hope to be able to adjust the idle when I get there. If it doesn't work I quess I'll have to change it.

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Old 12-23-2012, 09:26 PM   #14025
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Quote:
Originally Posted by Ladder106 View Post
Dr.E

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It's definitely improved my game!
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