650L, BadJuJU

Let me start with:

BigGun full exh., 165/55 jets, 13/48 on the sprockets, foam filter in the box which is opened up. I have not ground off the stop on the air/fuel screw so the bike is running rich right now, not enough to foul plugs, just smells really strong.

Now. If I start off running it hard it will smoke like a freight train, but if I start off on an easy ride, taking it through the gears without high revs, it won't smoke. I'm stumped as to if i burnt the rings being too rich, or beat the hell outta the valves/seats. I have no loss of power. I run 10w30 oil. Honda filters. No engine noise, valves or otherwise. Throttle response is a little sluggish, maybe due to not drilling slide to 5/32, but nothing to whine about. The bike is used weekdays 50miles a day on secondary roads to work, 50 to 70mph. Weekends, tight woods riding. It started smoking one day so bad I could hardly see the cars behind me! Then other days none at all, or maybe a little on decel.

:thumbsup:

Let me start with:

BigGun full exh., 165/55 jets, 13/48 on the sprockets, foam filter in the box which is opened up. I have not ground off the stop on the air/fuel screw so the bike is running rich right now, not enough to foul plugs, just smells really strong.

Now. If I start off running it hard it will smoke like a freight train, but if I start off on an easy ride, taking it through the gears without high revs, it won't smoke. I'm stumped as to if i burnt the rings being too rich, or beat the hell outta the valves/seats. I have no loss of power. I run 10w30 oil. Honda filters. No engine noise, valves or otherwise. Throttle response is a little sluggish, maybe due to not drilling slide to 5/32, but nothing to whine about. The bike is used weekdays 50miles a day on secondary roads to work, 50 to 70mph. Weekends, tight woods riding. It started smoking one day so bad I could hardly see the cars behind me! Then other days none at all, or maybe a little on decel.

:thumbsup:

first off, how many miles? what elevation? did this come out of nowhere or after a mod? you arent going to burn rings being rich, if anything it will run cooler. you may be too rich 165 main. mine would barely run with that jet. you need to get some adjustment outta the pilot circuit. do you have any engine mods(cam/piston)? did you daves mods or a dynojet kit? and yes drilll the slide either way.

first off, how many miles? what elevation? did this come out of nowhere or after a mod? you arent going to burn rings being rich, if anything it will run cooler. you may be too rich 165 main. mine would barely run with that jet. you need to get some adjustment outta the pilot circuit. do you have any engine mods(cam/piston)? did you daves mods or a dynojet kit? and yes drilll the slide either way.

7,500miles.

1,800 to 2,500.

about 2k after the mods.

no other engine mods, cam/piston.

the kit, FMF, came with a spring, 3 different main jets, (I bought the pilot from Honda), new needle, clip is 3 down from top.

7,500miles.

1,800 to 2,500.

about 2k after the mods.

no other engine mods, cam/piston.

the kit, FMF, came with a spring, 3 different main jets, (I bought the pilot from Honda), new needle, clip is 3 down from top.

so obviously its oil smoke. done a compression (wet and dry) or a cylinder leakdown test yet?

I have a 2001 XR650L with 18,000kms(stock) and it has the exact same problem with the smoking, and if i down shift it will smoke to. i took the snorkel off and it was runing lean so the fuel screw was spun to the stopper so i tryed to spin it back so i could grind the tab off and when i spun it it broke right off!! Now it is in the very lean stop and now i cant drive the pig

I did a dry compression test and it was like 85psi I think.

To do a real compression test, you need to loosen one of the exhaust valves so the auto-decomp is disengaged.

There is a spec for what it should be with the decomp in place, as well.

Manual, not handy right now.

Dave

I did a dry compression test and it was like 85psi I think.

do a dry then add some oil, maybe a coke cap full to the spark plug hole. then recheck if it increases a certain percentage you have ring issues. make sure to disable the ignition and hold the throttle wide open when testing.

To do a real compression test, you need to loosen one of the exhaust valves so the auto-decomp is disengaged.

There is a spec for what it should be with the decomp in place, as well.

Manual, not handy right now.

Dave

As always, excellent advice from the pro :thumbsup: Thanks for pointing that out.

165 is prolly too much main as MartinClown said. Sounds like time for a top end refresh. I prefer leakdown test but both are good ways to see what shape your top end is in wether it be a ring or valve problem. You sure about that 10/30 oil i think thats a little light for a L also.

I gotta ask some history ?'s here. Are you the original owner? did you breeakit in right? if not the rings may not have seated correctly, but IF that was the case I would think it would smoke (blue) all of the time. Coud be as has been mentioned dry and hard valve guide seals, especially if the bike sat a long time without running, or sometimes as a result of severe overheating the seals will wear prematurely, noce hard they allow oil to seep into the combustion chamber and thus the smoke. (if the smoke is blue - oil smoke) if it is smoking black, then the mixture is way too rich - caused by weak ignition or compression resulting in incomplete combustion, this will eventully lead to a fouled plug - plug will be oily black if there is worn rings. if you have only 85 PSI in the jug, you need to do a top end job.

I have taken all the advise that was offered here.....thank you very much TT'ers.

In light of the things mentioned here, I am lucky to have some friends help me along with the engine rebuild (discount parts, friends in a machine shop). A 101mm piston, Ti valves, valve job on the head, etc, along with a new carb has been priced along with all machine work, and I think I am going to go all out. I am starting next month, as the machine shop is backed up right now.

As to answer Motosprtman.....I am the original owner....as far as the break in, I broke it in hard, changed oil after 200miles, for the first 600miles, but I did run at a constant speed to work and back for a month, after 500 miles were put on the bike, as my primary vehicle needed rear diffs. AND...it did sit for a year at the 4k mark.

Have fun with it NUK it will be like a new bike when done GL

Nukin - well I have heard it said that these engine don't need an elaborate break in - as they are supposedly pre run at the factory.

......then I am in need of this rebuild then, I tend to dog a stocker, so I can rebuild it.....then I am OCD with the engine after being that I put $$$ in the thing.....I can't wait to see what a little mods can do to open the airhammer up...when I was a kid I rode with all these older fellas that had the big thumpers....YZ490....TT600....CR500.... KX420...you name it....all me and my paper route could afford was a ragged out 81 RM125......Now I run over the "older fellas" since all they own are UTILITY QUADS....no dig on the utils....but to see all the guyz I looked up to and rode with, sluggin' around on a couch....anyway....I am way ready to roid this bike out......Thanks again fellaz.

I have seen some nice looking bikes on this site.....I can guarantee you my airhammer will look like it just rode outta hell....and when I suck your Alpinestar boot into my intake as I pass you.....we can all have a beer knowing that crazy sumbitch on that Red bike WILL get to the finish line....somewhere between first........and last.

Keep us all posted no the rebuild and howgoesit! sounds like it will be one FAST BIG RED!

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