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Old 01-29-2013, 11:19 PM   #14491
bullittman281
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Joined: Dec 2007
Location: 4 corners-ish
Oddometer: 80
Hello,
I've been working w/ RE on this problem for quite a while now. I've know him for a long time. I haven't followed all that has been posted on this thread about the problems. The source of all of this was the bike started to run very poorly. I would have sworn that it was an electrical gremlin causing ignition troubles, but at this point there are no un-turned stones. That is what leads up to this point.

Apparently the bike is WAY down on compression from what it had when he bought it. What are you guys's thoughts on low compression or even broken rings causing the problems he's having? obviously an engine w/ very low compression will run poorly and be hard to start but do you guys think it would cause the bogging and spastic backfiring? Or are there multiple gremlins here?

I've looked at the photos and spoke with him on the phone and other than the bike running rich and maybe oiling a little bit I don't see a smoking gun in the pictures. If the valves seem to seal OK I think its time to pull the jug and get to the bottom of the low compression. It will never run right like that.

I fear though that even if he totally rebuilds the top end or even big bores it the original problem will still remain.

Earlier today he swapped out the entire electrical system w/ one that he got from somebody on this site. Swapping CDI's didn't change it but swapping the entire side cover w/ the stator resulted in no spark from the donor stator/side cover. I'm under the understanding that these parts came from running bike. If thats correct then I'm even more perplexed at what the issue is.

So a quick recap is the carb has been cleaned and adjusted multiple times so it should be perfect and ruled out as not the cause.
Valves were adjusted and checked to be in spec multiple times.
New plug, coil, coil wire, plug boot.
Swapping CDI boxes and the entire electrical system produced no change or worse problems.
Pretty sure that he removed the kill switch from the circuit.

Any other thoughts or does it all now point to low compression?
Personally I've never seen low compression cause THESE problems. Just hard starting and low power.

Sorry if some/all of this is 205, I haven't followed this thread until now.

Bullittman

Edit
RE beat me to the post while I was typing. sorry for the redundancy in the posts.
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Old 01-30-2013, 01:30 AM   #14492
tntmo
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The electrical system I sent was removed from a nice running 98 DR350. It has been stored in my rafters for about six months or so before I sent it out for troubleshooting assistance. No idea why the stator wouldn't work. Really wish it could have solved the problems.
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Old 01-30-2013, 04:41 AM   #14493
markk900
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I didn't want to say anything either cause that head looks fine other than the need for a carbon removal....after you check for leaky valves, the other thing I wonder is that could the auto decompressor be causing an issue?
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Old 01-30-2013, 05:26 AM   #14494
Txjack
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Txjack

Longgggg time lurker here, I've been following this latest grimln closely! 1st let me introduce myself. I've been on bikes of all sorts since 1966. Started on a Yamaha 80 2smoker, all the way up to an older Goldwing. I picked up a 99dr350 about 6mo.ago after reading the lions share of this fantastic thread. The bike only had 4100mi.& was in clean shape. Only got about 100 miles out of it before it went south. Mechanic who tore it down said that the timing gear shear pin sheared& I would have to have a new crank! I'm currently looking for a replacement motor. Sorry to be so long winded on my first post!
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Old 01-30-2013, 06:19 AM   #14495
Wadester
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Quote:
Originally Posted by RuggedExposure View Post
OK, got the head off and I think I see the problem.

Its not looking like an electrical issue or 'something small'...

(pics of crusty but ok looking parts)

so... parts bike?

or is it worth it to get a new head, valves, piston, etc?

What caused this? slop in the timing chain?
Your compression was way down. The valves look fine, but liquid check is a good idea. You've been completely thru the electrical/ignition system and it's fine.

The ridge on the cylinder doesn't look too bad - but I bet that your rings are stuck. That would explain the compression issue. But why stuck? Probably carbon buildup in the grooves. Maybe over time, but probably from the rich running conditions you described. You've had your carb apart - but we've never seen pics. At least one guy has commented on jets being vibrated out.

You will have to pull the cylinder and check/replace the rings. You need a ring compressor to get it back together - most auto parts places will loan them out for a deposit.

Take the carb apart and post pics - maybe someone with pumper carb experience can spot something. Otherwise, maybe someone could send you a spare carb? Even a "worn slide" version that idles erratically/etc would be good enough for a trial.
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Old 01-30-2013, 06:32 AM   #14496
a1fa
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You will probably have to re-hone the cylinder walls as well.
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Old 01-30-2013, 06:35 AM   #14497
mouthfulloflake
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parts bike, and not even a very good one.
sell it to me for cheap, Ill deal with the headaches.



No seriously, nothing wrong with it that i can see, other then the obvious low compression.
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Old 01-30-2013, 07:07 AM   #14498
2bold2getold
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Laugh

Quote:
Originally Posted by RuggedExposure View Post
Its hard dealing with this considering I just bought the bike in Sept, fought tooth and nail to get it street legal, got it fixed up the way I wanted it, then it started running like crap.

Its been down for nearly 2 months, and I've replaced or checked every part I can think of:
-plug
-coil
-spark plug boot
-cdi
-regulator
-stator
-all wiring harnesses
-carb
-valves
-fresh gas
-different fuel tanks and fuel lines
-clean air filter
Now it wont even start and has almost no compression.

I'm gone 60 hrs a week for work and I make too much money to be dealing with this kind of bullshit from a bike.
Thats why I'm driving to Texas tomorrow to put money down on a Terra 650 so I can have the next one that arrives.

If this was a restoration project or a bike that I had running reliably for years, I could understand taking my time with it and figuring out what is troubling it. But since it doesn't even have 5k miles on it, Suzuki is starting to drop down to the likeness of Chrysler products in my book.
Pull the valve springs and check the valve stem seals for wear/cracks/loose. If you don't need/want to replace the valves/guides, you can get some fine valve lapping compound and lap the valves and install new seals. Clean up the valves with a fine wire brush on a bench grinder (with eye protection). You can use smaller wire brushes in a drill motor on the head. Try to stay off the mating surfaces. Or better, if you know someone with a glass bead cabnet/media blaster, they work great. Pull the jug and check for stuck/broken rings. Your wife probably doesn't need/want a big bore cylinder. If the piston/cylinder isn't too bad, hone the cylinder to break the glaze and get fresh cross hatch and get new rings. Sometimes you can carefully get the cylinder back on the piston by pushing the rings in with your fingers and carefully pushing down the cylinder at the same time. On some motors you can also put the piston in the jug on the bench just past the bottom ring and slide the assembly down onto the rod and then install the wrist pin and keepers. Take your time, you're gonna have a new bike soon and with a little effort and a few bucks you will wind up with a nice fresh DR also. This may not be the problem for the poor performance, but what ever it is, it's gonna show up. Don't give up. You have lots of help here. It's nice to have several people to give opinions, some one's gonna come up with something soon. In the end motors are pretty simple. Compression, fuel/air at the correct ratio, and spark at the right time. Simple, right.

2bold2getold screwed with this post 01-30-2013 at 07:25 AM
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Old 01-30-2013, 07:17 AM   #14499
RuggedExposure
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I hope you all are right. Even if I part this junker out, I'm still going to have to roll the dice on a criagslist buy that may have worse problems. So I might as well keep this since its street legal. Hopefully later today I can do the liquid test on the heads. If it fails miserably (seeps liquid quickly), is that most likely the source of my problems?

I'll also start on pulling the jug. I have downloaded the DR350 shop manual. Does anyone else have a link to other online literature on taking these things apart and putting them back together?
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Old 01-30-2013, 07:20 AM   #14500
mouthfulloflake
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a leak down test while the engine was together would have been helpful

what was the actual compression reading? did you check it with a gauge?
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Old 01-30-2013, 07:22 AM   #14501
RuggedExposure
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Quote:
Originally Posted by Wadester View Post
Your compression was way down. The valves look fine, but liquid check is a good idea. You've been completely thru the electrical/ignition system and it's fine.

The ridge on the cylinder doesn't look too bad - but I bet that your rings are stuck. That would explain the compression issue. But why stuck? Probably carbon buildup in the grooves. Maybe over time, but probably from the rich running conditions you described. You've had your carb apart - but we've never seen pics. At least one guy has commented on jets being vibrated out.

You will have to pull the cylinder and check/replace the rings. You need a ring compressor to get it back together - most auto parts places will loan them out for a deposit.

Take the carb apart and post pics - maybe someone with pumper carb experience can spot something. Otherwise, maybe someone could send you a spare carb? Even a "worn slide" version that idles erratically/etc would be good enough for a trial.
Thanks for the visual (I was wondering what a ring compressor looked like). Autozone has something similar for $10. Since I'll be making the 2 hour drive to town (to put money down on my Terra 650 ) I might as well pick one up today.

I'll also take the carb apart and post pictures for some carb experts to look at. I've had that damn thing apart 10+ times in the past month so its no big deal. Hey, maybe the 11th time is the lucky time and I'll find my gremlin.
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Old 01-30-2013, 07:35 AM   #14502
Wadester
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Quote:
Originally Posted by RuggedExposure View Post
Thanks for the visual (I was wondering what a ring compressor looked like). Autozone has something similar for $10. Since I'll be making the 2 hour drive to town (to put money down on my Terra 650 ) I might as well pick one up today.
Someone else made the point - cleaning up the ridge at the top of the cylinder! You need a cylinder ridge reamer:

and a cylinder hone:

Both available for "loan/lease".
Or you can buy a cheap "abrasive balls on wires" type hone:


Just make sure they will go small enough for a DR (79mm/3.1")
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Old 01-30-2013, 07:37 AM   #14503
Chicken Helmet
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http://advrider.com/forums/showpost....7&postcount=45

Could this be causing any of the issues?
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From what I've heard, riding a DR feels just like riding a KLR except you're head doesn't sway left and right constantly scanning the ditches for aluminum cans.
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Old 01-30-2013, 07:42 AM   #14504
ADV BUM
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What is a low miles, running kickstart engine worth?
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Old 01-30-2013, 07:48 AM   #14505
2bold2getold
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Joined: Dec 2011
Location: DFW TX
Oddometer: 1,297
Quote:
Originally Posted by Wadester View Post
Your compression was way down. The valves look fine, but liquid check is a good idea. You've been completely thru the electrical/ignition system and it's fine.

The ridge on the cylinder doesn't look too bad - but I bet that your rings are stuck. That would explain the compression issue. But why stuck? Probably carbon buildup in the grooves. Maybe over time, but probably from the rich running conditions you described. You've had your carb apart - but we've never seen pics. At least one guy has commented on jets being vibrated out.

You will have to pull the cylinder and check/replace the rings. You need a ring compressor to get it back together - most auto parts places will loan them out for a deposit.

Take the carb apart and post pics - maybe someone with pumper carb experience can spot something. Otherwise, maybe someone could send you a spare carb? Even a "worn slide" version that idles erratically/etc would be good enough for a trial.
Nice shot of a ring compressor....That's an interesting picture. Normally, you would install the piston from the bottom of the cylinder, or slip the cylinder down onto the piston. On most cylinders there is a chamfer (not a square edge) on the bottom to help the rings slide into the jug.
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