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Old 02-16-2012, 11:20 AM   #4261
AMCJEEP
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Quote:
Originally Posted by cbig View Post
I'll take the bike to the Barstow area this weekend for a shakedown, try and find some sand and rocks to run it on. (Best variety I can out there to see what the suspension was reworked to solve)

The electrics looked well done which is why I decided to step up and buy it. Hope it's not too trail heavy - might wind up being a DR350SE!

I have only ridden one dr350se, and it was a 1994 model, but there is no comparison to my 98 xr400. Dr350 is a good bike for what it is, split duty between road and dirt, but Didn't even compare on the trails.
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Old 02-18-2012, 11:56 AM   #4262
TDubben
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Valve Clearance question

Hi all. I just recently got a great deal on a 98 XR400. I'm new to setting the valve clearance and had a question. I tried getting the .004 in feeler gauge in on one of the intake valves but it wouldn't go. So I loosened up the adjusting screw until i could fit it in, then tightened it down until there was slight resistance on the feeler gauge moving back and forth. Is this a good way to set clearance?

Also, I'm pretty sure the PO never adjusted the valves. The caps required 2 people to remove. Since I adjusted them, I am now showing between 3-4 threads sticking above the locking nut (no threads before i adjusted). Is that too many?

And last question, From top to bottom there is the adjusting screw, rocker arm (i think), and valve. Should i be sticking the feeler gauge between the rocker arm and the valve or the rocker arm and the screw? The manual says between the adjusting screw and sub-rocker arm, but all the pictures I've seen in How-tos look like its at the valve?

I left the valve caps loose incase i screwed it up and need to redo

This picture shows the threads and where I believe I need to be checking the clearance (per the manual)

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TDubben screwed with this post 02-18-2012 at 01:03 PM Reason: Editing to add Picture
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Old 02-18-2012, 01:39 PM   #4263
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Quote:
Originally Posted by TDubben View Post
Hi all. I just recently got a great deal on a 98 XR400. I'm new to setting the valve clearance and had a question. I tried getting the .004 in feeler gauge in on one of the intake valves but it wouldn't go. So I loosened up the adjusting screw until i could fit it in, then tightened it down until there was slight resistance on the feeler gauge moving back and forth. Is this a good way to set clearance?

Also, I'm pretty sure the PO never adjusted the valves. The caps required 2 people to remove. Since I adjusted them, I am now showing between 3-4 threads sticking above the locking nut (no threads before i adjusted). Is that too many?

And last question, From top to bottom there is the adjusting screw, rocker arm (i think), and valve. Should i be sticking the feeler gauge between the rocker arm and the valve or the rocker arm and the screw? The manual says between the adjusting screw and sub-rocker arm, but all the pictures I've seen in How-tos look like its at the valve?

I left the valve caps loose incase i screwed it up and need to redo

This picture shows the threads and where I believe I need to be checking the clearance (per the manual)


I stick the feeler gauge in like you did.

If the bike was running about right and you moved the adjusters more than a half turn then you did it wrong.

I'd guess that you set the motor to TDC on the exhaust stroke, not TDC on the compression stroke. Rotate the crank one turn from where you adjusted it. You should be unable to wiggle the rockers with your fingers. If there is a lot of slop (like 1/8 inch) then re-adjust the clearance there.

Also make sure that the manual decompression lever is not engaged. I prefer to turn the motor over with a socket and breaker bar. A ratcheting socket wrench will cause you to lose your place when the valve springs turn the motor forward.
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Old 02-18-2012, 02:23 PM   #4264
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The bike wasn't running well at all. Very hard to start. Wouldn't hold idle and surged really badly while driving.

For TDC, I lined up the "T" mark and there was a ton of play so I rotated 1 complete turn and there wasn't hardly any play. That's where I adjusted them. I'm guessing this is where I messed up. Thanks for the heads up. Time for me to readjust
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Old 02-18-2012, 03:56 PM   #4265
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Quote:
Originally Posted by TDubben View Post
The bike wasn't running well at all. Very hard to start. Wouldn't hold idle and surged really badly while driving.

For TDC, I lined up the "T" mark and there was a ton of play so I rotated 1 complete turn and there wasn't hardly any play. That's where I adjusted them. I'm guessing this is where I messed up. Thanks for the heads up. Time for me to readjust

Sounds like the last guy got it wrong- and may be the reason you got such a good deal. The valves should be tight (held slightly open) at TDC-E and have a little play at TDC-C. By a little play, I mean enough that you can feel it move when you wiggle it, but barely see any motion.
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Old 02-18-2012, 05:01 PM   #4266
TDubben
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Quote:
Originally Posted by Luke View Post
Sounds like the last guy got it wrong- and may be the reason you got such a good deal. The valves should be tight (held slightly open) at TDC-E and have a little play at TDC-C. By a little play, I mean enough that you can feel it move when you wiggle it, but barely see any motion.
That was it. Once I had it on the right stroke, I set the clearance and now the play is as you describe it.

Now if I can only figure out how to get the sparkplug out . I'm waiting on the Honda tool from the toolkit I found on ebay. Can't wait to see how lean he had been running this bike. It had all the intake mods done but stock jetting.
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Old 02-18-2012, 05:35 PM   #4267
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when you get the "proper" plug wrench..TAKE YOUR TIME and dont round off the plug..I did that once and I had to remove the head to get the stupid plug out..be sure to blow out any dirt and debris out first...good luck
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Old 02-18-2012, 06:06 PM   #4268
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Quote:
Originally Posted by Ed@Ford View Post
Thanks for that bit of trivia...gotta do that. But a question for other folks who have had to fix this...is the "freeze up" the bolt in either side of the frame, or the bushing that goes thru the back end of the engine? Here's my assessment of my situation....I don't expose the bike to lots of mud and water...but what i DID do was have a bunch of welding done on the tab that the sidestand bolt goes thru....I let someone borrow my bike...and sure as shit the sidestand came back messed up and the sidestand tab had literally torn open the frame....got it back in shape and welded it....and my bet is the whole frame is stressed and it may be caused the swing arm bolt to bind up.....I'll find out for sure when I start drilling out the boltfrom the LH side of the frame where the sidestand tab is. To be safe I bought the frame and swing arm a guy had for sale on this thread...it isn't pretty...but swing arm is in decent...and the bolt was not siezed.

Oh...yeah. what is plumber's freeze spray? Like liquid nitrogen cold...-300F....or acetone and dry ice...which gets to maybe -135F?
I am one of the people who has fixed this issue created by Honda and previous owners lack of maintenance. And fixed it withought use of a new frame and swing arm or eaven a new swingarm like Doc.....

There are two issues going on here, first is the seizing of the bearing bush's on the bolt, if this happens you can turn the bolt but not extract it. second is the seizing of the bolt in the steel bushes in the engine cases. When this happens you cant turn the bolt and the bearing bushes are probably seized as well.

I doubt your frame is twisted but it is a dirt bike so who knows.

However you do the job you can either spend money or use a BFH, forget 14lb hammers, they are toys, get a real hammer and swing it like your life depends on it.

When you are done fit a grease nipple to the engine casing and fill the casing/bush's with grease then your bolt will never seize there and make sure you pull out the swing arm bolt every year and grease it. I fitted grease nipples to the swing arm as well but this only greases the bearing not the bush/bolt so you will still need to pull the bolt and grease it.

If you have access to oxy/acetylene or oxy/propane forget the plumbers freezer spray, just use water as a coolant.

Plumbers freeze spray is available in hardware and diy shops here, what it is I dont care, but it will freeze water in a copper pipe so quite cold.

Good luck with this job!

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Old 02-19-2012, 06:17 AM   #4269
fuel-cycle
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swing arm bolt seizure

All with this affliction, try using Aero Kroil by Kano Labs.

http://www.kanolabs.com

Kroil is the oil that Creeps. Amazing stuff!
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Old 02-19-2012, 01:13 PM   #4270
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Carburation issue?

Okay fellas... just picked up my new '01 xr400. It's got some fun stuff on it. DS kit (Tusk I think?), big tank, skid plate, yadda yadda... Appears to have very little wear/tear overall. Rear swing arm bolt spins freely (but probably needs lube), but does need a new front fork seal, and to set rear suspension height.

Issue:
Upon test drive I noticed that under full throttle acceleration the bike bogs once the rpm's get up to probably "3/4" of max rpm. The bog is pretty significant, and it won't stop bogging - although it will continue to accelerate a bit - but clearly something's off.
I checked the jet size = 142... which is probably small for Denver altitude. I also replaced the spark plug (it was a "9" instead of the stock "8"), and put in fresh gas. No change.

I looked through about 80 pages of this forum, but didn't see related stories along these lines...

Any XR wisdom to share?

Thanks in advance for any help...

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Old 02-19-2012, 02:04 PM   #4271
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Quote:
Originally Posted by Light Rider View Post
Okay fellas... just picked up my new '01 xr400. It's got some fun stuff on it. DS kit (Tusk I think?), big tank, skid plate, yadda yadda... Appears to have very little wear/tear overall. Rear swing arm bolt spins freely (but probably needs lube), but does need a new front fork seal, and to set rear suspension height.

Issue:
Upon test drive I noticed that under full throttle acceleration the bike bogs once the rpm's get up to probably "3/4" of max rpm. The bog is pretty significant, and it won't stop bogging - although it will continue to accelerate a bit - but clearly something's off.
I checked the jet size = 142... which is probably small for Denver altitude. I also replaced the spark plug (it was a "9" instead of the stock "8"), and put in fresh gas. No change.

I looked through about 80 pages of this forum, but didn't see related stories along these lines...

Any XR wisdom to share?

Thanks in advance for any help...
Looks like a nice clean bike, congrats!

What elevation will you be riding your XR in mostly?

Did you ask the previous owner where he rode the bike? Has the bike been sitting for a while? (Probably, it's winter) It might be a tad lean down in Denver but once you get up to the trails around here it'll probably run good. It's also cold out, so that will make it run lean as well. Also, make sure your air filter is clean and if the snorkel hasn't been removed, you might want to do that.

What did the old spark plug look like?

I've found that multiplying the stock main jet size by a correction factor of .92 (this info is in the Honda manual) usually gets you to a place to start for our elevation.

Honestly though, I'd buy a couple of jets, like a 145 and a 148 and wait until the riding seasons starts before messing with the jetting. Chances are the PO had already jetted the bike for our high altitude riding and the bike's only running this way because it has probably been sitting through the winter. Wait until it warms up and you're actually riding the bike where you'll normally ride to mess with the jetting.
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Old 02-19-2012, 02:09 PM   #4272
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Quote:
Originally Posted by Light Rider View Post
Issue:
Upon test drive I noticed that under full throttle acceleration the bike bogs once the rpm's get up to probably "3/4" of max rpm. The bog is pretty significant, and it won't stop bogging - although it will continue to accelerate a bit - but clearly something's off.
I checked the jet size = 142... which is probably small for Denver altitude. I also replaced the spark plug (it was a "9" instead of the stock "8"), and put in fresh gas. No change.
Wow, that bike looks new!

Has anything been done to the exhaust or airbox?

Here's a carb guide:
http://www.4strokes.com/tech/honda/carbadj.asp

It's based on the 96/97 years. 142 is the stock '98+ jetting. IMO, the 98+ needle with roughly 96/97 jetting is the best.

Assuming the airbox snorkel and exhaust baffle are gone:

Following the chart, I'd go for about a 152 main jet. You should have the good needle (A16A), leave that on the stock setting (3rd clip). I like the 62 pilot jet, even at altitude. It is a little rich, but makes cold starting easier. Maybe try 60 at your altitude.
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Old 02-19-2012, 04:32 PM   #4273
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Olas / Luke,
thanks for the replys.

As far as the PO. No real clue. I bought the bike off a guy that was basically flipping it, as best I could tell. So I have no info there.

Here is a pic of the original spark plug - which looks fine to me, but my experience is limited... but then again, I'm not even sure this bike originally came from Colorado?
Photobucket

General riding elevation: We usually ride locally anywhere from 7000-10,000'. But we're getting ready for Moab in a few weeks (4000'), so I guess the answer is - the gamut. But I would say, the majority is here in CO.

Oh - and I failed to mention - the snorkel was removed. (and currently there is a K&N filter, which I'm planning on replacing). And exhaust is FMF PowerCore 4.

Thanks for the chart Luke - I'll check it out for sure. To be honest, I've never torn into one of these carbs before so I'm not familiar yet with how to check the needle position etc. But if need be I'll dive into it soon.

Given that I'm new to the XR, anything else I should be looking for? I know I should probably lube the headset and swing arm yes? And probably check the valve lash, I'm sure...

Any other thoughts?
Most appreciated...
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Old 02-19-2012, 09:42 PM   #4274
Luke
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Originally Posted by Light Rider View Post
Given that I'm new to the XR, anything else I should be looking for? I know I should probably lube the headset and swing arm yes? And probably check the valve lash, I'm sure...

Any other thoughts?
Most appreciated...

The plug looks good enough to me, but I'm no expert there.

Things to check? I'd do what you said; and add an oil change, brake fluid change, check the spokes for tightness, check the wheel bearings, check the tires and inner tubes for cracking/age, brake pads for amount of material.

For 4k' I think a 155 main is best. For a variety of altitudes, I've heard to jet for the lowest elevation and let it run a little rich when higher. That's worked well for me.
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Old 02-19-2012, 10:04 PM   #4275
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Originally Posted by TDubben View Post
That was it. Once I had it on the right stroke, I set the clearance and now the play is as you describe it.

Now if I can only figure out how to get the sparkplug out . I'm waiting on the Honda tool from the toolkit I found on ebay. Can't wait to see how lean he had been running this bike. It had all the intake mods done but stock jetting.
I bought the right socket for like $1 from a pawn shop and chucked it up in a drill press then used an angle grinder to clearance it. took all of 10 minutes, saved a few bucks, and didn't have to wait for shipping. painted it honda red lol.

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