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Old 07-19-2013, 03:37 PM   #60751
tractor4play
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opinions

Quote:
Originally Posted by tractor4play View Post
i have just done a dry build with a rfvc 650 bottom mated to xl600r barrel,stock piston and twin carb head.
without gaskets the piston is 1.3mm above deck height.so with double base gaskets and stock head gasket i should just about clear zero deck.
has anybody done this without issues..valve to piston clearance etc.
any advice would be great.
I would like some opinions from the redular gang on here.
HT,Steve and CW etc.
Regarding the camchain being 1.3mm out of place i dont think it would
have a noticeable effect.Please correct me if i am wrong.
Thanks T.
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Old 07-19-2013, 03:41 PM   #60752
techforlife
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Quote:
Originally Posted by tractor4play View Post
I would like some opinions from the redular gang on here.
HT,Steve and CW etc.
Regarding the camchain being 1.3mm out of place i dont think it would
have a noticeable effect.Please correct me if i am wrong.
Thanks T.
You`d have to slot the cam gear.....as the timing will be advanced......might not hurt a thing,,but it will increase low end at the expense of top end power..

Increase the thickness of the base gasket........do not double up on the head gaskets..or a solid copper head gasket works too.

B
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Old 07-19-2013, 04:03 PM   #60753
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Quote:
Originally Posted by beechum1 View Post
Jeff suggested these in the XR600 thread when you axed the same question a week ago.
I just never saw the answer, sorry, but thanks for the info.
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Old 07-19-2013, 04:04 PM   #60754
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Quote:
Originally Posted by mrfixit54016 View Post
go to fleabay and type in


99 xr600r acerbis frame guards


and i bet you may find some there.

Or try power sport junkie or many others for the ufo brand.

http://www.powersportjunkie.com/ufo-ho02685041-p/pu-12-488-29.htm
thanks!!!
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Old 07-19-2013, 04:31 PM   #60755
mcma111
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Quote:
Originally Posted by tractor4play View Post
I would like some opinions from the redular gang on here.
HT,Steve and CW etc.
Regarding the camchain being 1.3mm out of place i dont think it would
have a noticeable effect.Please correct me if i am wrong.
Thanks T.

If the piston is 1.3mm above the top of the cylinder and you used a 1.3 mm spacer of some type at the bottom of the cylinder you would end up raising the center of the cam 1.3 mm. You would not see 1.3 mm on one side of the cam chain but .65 mm on either side. 1.3 mm split by 2 = .65 mm. The cam timing change would be negligible.
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Old 07-19-2013, 05:02 PM   #60756
joexr
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Quote:
Originally Posted by mcma111 View Post
If the piston is 1.3mm above the top of the cylinder and you used a 1.3 mm spacer of some type at the bottom of the cylinder you would end up raising the center of the cam 1.3 mm. You would not see 1.3 mm on one side of the cam chain but .65 mm on either side. 1.3 mm split by 2 = .65 mm. The cam timing change would be negligible.
You've got it backwards. I f the cam goes up 1.3mm , that's 1.3mm per side and2.6mm total slack out of the chain. Can the tensioner give that much?
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Old 07-19-2013, 05:23 PM   #60757
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FCR-MX Slow air screw question

I got my slow air screw kit this week and looking at it next to a slow air screw I am puzzled as the adjustable screw needs a much larger hole. Is the slow air jet passage a stepped hole?
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Old 07-19-2013, 06:46 PM   #60758
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Quote:
Originally Posted by joexr View Post
You've got it backwards. I f the cam goes up 1.3mm , that's 1.3mm per side and2.6mm total slack out of the chain. Can the tensioner give that much?

That`s not the only issue.like i said........

Look at it like this.......the timing chain is under under tension on the rear side...the front is basically straight up/down from gear to gear....now..if you raise the head the cam gear cannot go straight up in the front without the cam gear turning from it`s TDC marks to allow the slack.........the tensioner side will allow that because all the slack is on that side..........so if you raise the head.......all chain slack is provided by the tensioner side so cam timing will be an issue...

If the head moves up 1.5mm ...........all that chain slack comes from the tensioner side and the cam turns to provide all that 1.3mm clearance needed..

So the cam will turn that 1.3mm and you are right that 2.6mm chain slack is needed to even lift the head that much..

And you have a valid point,will it allow 2.6mm of extra chain length without issues..

B
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Old 07-19-2013, 08:08 PM   #60759
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Cool2 overflowing with questions...

With no mechanic buddies to ask and being a baby to all this stuff you guys are my hope for some sanity..

in short heres the story.

Bought first bike(95 xr650l, stock jets, k&n filter, stock muff) after cruising this forum for months and really getting to love these xrls.

got ripped off unfortunately (desperate for summer ride)

bike was not treated nicely by last owner (sold it with no oil showing on the dipstick) which i didnt even think to check until after i rode it home.. :/

every time i looked closer at the bike, more problems.

cleaned carb, cleaned filter, new muffler gaskets, oil change, new spark (came out jet black carbon fouled after every ride) ..seemed to ride o.k. but..

high end of any gear = smoke smoke smoke

1st compression test : DRY 100psi WET 115psi (decomp engaged)

(thought that cant be right.. adjusted valve clearence)

2nd compression test: DRY 85psi WET 88psi (decomp engaged)

manual says 92psi with decomp engaged..

wasnt really sure how bad those readings were but went into the top end this is what it looks like..


















there was definatly some slight play in the piston pin and when i rock the connecting rod side to side it moves about 1mm but has no up and down freeplay


not sure how helpful those photos are for enlightening me on what kind of top end job i should do here but

i guess im just looking for any advice regarding what parts i should be looking into and where to get? /next course of action

or any advice at all about anything at all hah.

also wondering about some tools.. whats a good sized torque wrench to get for these bikes? brand? preferences/ opinions

(sorry for flood of pics)

cheers, you guys rule.
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Old 07-19-2013, 08:25 PM   #60760
mcma111
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Your cam and rockers are shot. You need to bore the cylinder up a size and replace the piston. Slide the wrist pin in the rod but only the outer end of the pin. Now check for play as the center will have worn. Some play is the normal for these engines. The rod side to side is also common. A non issue. The piston and cylinder head combustion chamber are clean due to all of the oil passing the rings and washing the carbon away. Where are you??
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87 Harley FXRS-SP ~ 06 KTM 625 SMC ~ 72 Honda CB750/915cc ~ 92 XR600/654cc ~ 95 XR650l/675cc ~ 03 CRF450r ~ 05 CRF450x ~ 02 XR650l/675cc ~ 86 YZ490 ~ 93 YZ80 ~ 93 XR650l Project
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Old 07-19-2013, 09:02 PM   #60761
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+1 also like i said on TT..........consider changing the timing chain with that mileage,18K MILES,and possible rails and tensioner.......if the marks do not line up it`s worn...go in once,do it right........

B
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Old 07-19-2013, 11:54 PM   #60762
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Adj Air Screw will NOT fit FCR MX

I tried to install the Adjustable Air Screw kit I got from Power barn into my FCR MX and it will not fit, not even close. The threads are about 2.5 mm wider than the fixed screw, so I suspect this part may be for the Slant Body FCR only.
It was advertised for all FCR carbs so I'm a bit peeved.
Only way I can see this going in would be to drill and tap the airscrew orfice for limited gain anyway.
15 bucks down the tube.....
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Old 07-20-2013, 04:28 AM   #60763
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Quote:
Originally Posted by Fingers View Post
I tried to install the Adjustable Air Screw kit I got from Power barn into my FCR MX and it will not fit, not even close. The threads are about 2.5 mm wider than the fixed screw, so I suspect this part may be for the Slant Body FCR only.
It was advertised for all FCR carbs so I'm a bit peeved.
Only way I can see this going in would be to drill and tap the airscrew orfice for limited gain anyway.
15 bucks down the tube.....
I emailed them this is complete bullShit, will be hitting my card services up to deny the charges next. You should do the same.
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Old 07-20-2013, 05:06 AM   #60764
Fingers
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Agree Nic, please post their response, I searched a lot and I'm surprised I can't find anything about how it goes in!?! Since the threads are a good 15 mm from the needle seat it looks like they want you to tap and thread the "mouth" of the orifice leaving the original seat threads intact.
Too much work for the questionable benefit of adjusting the slow air mixture, and since you still have to take the carb off to get to it, not to mention the NOSS needs drilling for access as well, your better off just getting a few sizes up or down to adjust the mixture, if its even needed.....

http://www.power-barn.com/servlet/th...-dsh-MX/Detail

You gotta love the below install instructions on the site:

The kit contains a screw and a spring. You remove your fixed size slow air jet and install the screw with the spring installed over the end. See the chart below for the jet size to adjustment correlations.
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Old 07-20-2013, 06:38 AM   #60765
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Quote:
Originally Posted by Fingers View Post
Agree Nic, please post their response, I searched a lot and I'm surprised I can't find anything about how it goes in!?! Since the threads are a good 15 mm from the needle seat it looks like they want you to tap and thread the "mouth" of the orifice leaving the original seat threads intact.
Too much work for the questionable benefit of adjusting the slow air mixture, and since you still have to take the carb off to get to it, not to mention the NOSS needs drilling for access as well, your better off just getting a few sizes up or down to adjust the mixture, if its even needed.....

http://www.power-barn.com/servlet/th...-dsh-MX/Detail

You gotta love the below install instructions on the site:

The kit contains a screw and a spring. You remove your fixed size slow air jet and install the screw with the spring installed over the end. See the chart below for the jet size to adjustment correlations.

If this is like the "Flex Jet" I bought for the stock FCR39 on my KLX400R, then the problem is just the hole in the bowl, say that fast 5 times, is too small. The hole in the base of the carb itself is ok. Take the bowl off and check if the screw will fit in the carb. If so, just drill out the hole in the bowl a size larger, or even file it a little. Easy-peasy*.





* credit: Steve
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