58 replies to this topic

[kcampbe TT Newbie]

Thanks for the research and lead on the shock.  Not cheap!

All of the KX shocks I looked at had reservoirs - not sure how that would work.

It looks as though there isn't a way to get the spring off the shock, because I was pondering whether I could measure it and just get a new spring if the shock isn't leaking...

[Smacaroni Get Help Now]

On the DRZ/KX swap, you have to put the reservoir on the left side and remove the chain roller.
The spring may come out by unscrewing the small end of the shock. Look at the parts diagram to be certain. If that's the case, they're often a royal pain, but do come apart.

[Smacaroni Get Help Now]

On the DRZ/KX swap, you have to put the reservoir on the left side and remove the chain roller.
The spring may come out by unscrewing the small end of the shock. Look at the parts diagram to be certain. If that's the case, they're often a royal pain, but do come apart.

[Smacaroni Get Help Now]

I finally killed the bog. I don't know if this is an indicator that the needle, needle seat or needle jet is wearing out, but dropping the needle 1 clip (move the clip 1 step closer to the end of the needle) eliminated the quick-open throttle bog.
Also found out I'm running a #100 main, which seems kinda small, but according to the parts diagram, is stock.

[MFSeniorC TT Newbie]

Hey Smacaroni -
First, I am new to posting so I apologize if this messes up.
Second, thanks for posting all of your discoveries and photos, professor.
Third, if you don't mind sharing just a few more pointers, I recently scored a 2006 DRZ125 complete exhaust on flebay and intend to do the same switch you did in November to my 1994 DR125SEL.  My son only uses it for trails and its generally a good bike but as you know it's underpowered for its weight.
(kept front & rear lights but stripped mirrors, turn signals & luggage frame.  Prev. owner installed tidy little UFO rear fender/light but I had to wire it.). I'm not going to go crazy trying to make it something that it isn't, but I hope that less weight and any added boost from the new pipe will help.  (Lighter used wheels would be cool... the steel ones sure are hefty.)  Anyway,
Did you make any carb adjustments after the pipe switch?  
Past routine maintenance and pipe swap, any other advice on tuning it for best output (short of top-end swaps / big projects)?
Link to photo: http://www.bikepics....ctures/1024781/

Smacaroni said:

Over the weekend I threw a DR-Z125 complete exhaust onto my ugly DR125.
Almost a perfect fit. Install the silencer before tightening down the head bolts, or you'll never get it on. There's one hole in the middle of the pipe that you probably should drill one to match the frame, I didn't though, I think it will be fine. Takes about 15 minutes to install.
The modern piece is so much lighter, probably 1/2 the weight of the stock DR piece.

Sounds like a DR-Z125, although there's a tiny metallic under tone to it. But it looks natural. Before:


After:

[Smacaroni Get Help Now]

IIRC, I think I ended up dropping the needle one clip and that was it for carb changes.
No big plans for the DR125, it was just a beater buddy bike and I think that's what it's current owner planned to do with it after I sold it to him.
Best bang for the buck power wise, at least from what my experience with our DR-Z125 is a SP200 motor complete swap.
Check out this thread: http://www.thumperta...885#post9734885

[87dr125 TT Newbie]

so an aftermarket exhaust for a drz125 will fit on my dr125 1987 ????

[Smacaroni Get Help Now]

Yes. Be sure you start all the fasteners prior to tightening them down though. The fit is close enough that it will fall into line, unless you've tightened down one of the other bolts before starting one - you'll just get very frustrated trying to thread that last bolt. If it doesn't want to cooperate for what ever reason, skip the one on the frame where the pipes join together. This is not absolutely necessary.
Jetting changes suggested would be similar, but not exactly the same since the DR uses a 20? mm carb vs. the 22? mm the DR-Z uses.

And I see my server at home has taken a dump again. If you want photos, I'll upload them somewhere else.

[87dr125 TT Newbie]

Thanks a lot bud.
I just picked this thing up yesterday, not too much stuff about these things.  Do you know of a place that has any specification type information??
I willl make a thread and try to get some pics of the old dog.

[Smacaroni Get Help Now]

I used the DR-Z125 manual, it's practically the same engine wise. Carb is different, but it's close enough. Frame general torque specs for axles, clamps etc. will be fine.

Good luck.

[Ian Duffin TT Newbie]

can anyone tell me what kind of carb was on the 86 Sp125? Ive been researching it trying to find a rebuild kit

i bought the bike non running for like 200 bucks, got it running (very, very roughly) and with gas climbing like it is i want to throw it on the road as an a commuter

bike only starts when you block off intake of carb with your hand, then kick it over with your hand in place (acting as a choke) obv needs to be fixed
and then, once its running, no matter how hot or cold it is, if you rev it up past like 1/2 throttle, after releasing the throttle it backfires, every time, without fail

any fixes? ill start making it fast once it runs decently x)

thanks guys!

[Smacaroni Get Help Now]

Start by cleaning the carb, completely, again.
Couldn't find anything on the 86, but here's the 87: http://www.suzukicyc..._sales4_900.jpg

[Ian Duffin TT Newbie]

My buddy thought it might be lack of compression for the starting issue, and I believe the carb is a mikuni vm26,

But, no dice confirming it

[Smacaroni Get Help Now]

Personally, I'd go looking for a DR-Z125 carb, throw that in and forget about it. I do know the SP and DR had different carbs, at least what ever model and year I happened to be researching. Might have been the DR/SP200 though... VM26 seems a little big for a 125, but perhaps if it's a pumper (TM?) instead of a round slide? For some reason, I think the DR got a VM20. Are there any numbers or markings on the carb body?

Edited by Smacaroni, 28 February 2012 - 07:34 AM.

[Ian Duffin TT Newbie]

Its definitely a round slide, but ill pull thecarb tomorrow and check it out

Internals? Timing? Rings?

8500 on the bike if what looks to be rough riding,

How much is a used drz carb do you think?

[Smacaroni Get Help Now]

Rings? Do a compression test. The DR/SP/DR-Z125 & KLX125 (green plastics, made by Suzuki) motor is a great power plant, it's not maintenance intensive and will run practically forever with the only thing to check occasionally is valve clearance. If your compression numbers are low, check the valves first. Actually, I would suggest checking the valve lash even if it's running great, since it's a new acquisition. Have you tried cleaning the carb again? Completely disassembling it and soaking it in parts cleaner - except for rubber or plastic pieces the parts cleaner will ruin those.

There's new ones listed on ebay for $80, but they look like they might be Chinese imitations. There's a used KLX125 carb on ebay for $90.
Everything but the transmission on your motor can be replaced with DR-Z125 parts. The DR-Z has a 5spd transmission, I'm pretty sure the DR/SP125 are six speed. Keep this in mind if you need to replace anything.

Edited by Smacaroni, 29 February 2012 - 05:38 AM.

[Ian Duffin TT Newbie]

Thanks, my buddy has a valve grinder, so ill get those polished up

The carb, that's a different story, its been rebuilt a couple times, but I need new jets for it, one if the jets is semi clogged with something I can't bore out
I swear the carb is the biggest issue, when it was running, none of the screws seemed to change a thing. And, something I just noticed today, was that at dead center with the handle bars, the front wheel turns right? Its that a, set of bent forks,  or can that be adjusted

And I believe the 2 air boxes from sp to dr are different, I have 2 sitting side by side, and One certainly doesnt fit

[Smacaroni Get Help Now]

Check that your steering stem is tight, I had the same problem on our DR and it took me a while to find that the nut got loose. Since you're planning to plate it, I would go so far as to disassemble, inspect and at least grease the bearings, if there's any notchyness or sticky spots, just replace the bearing and race, better safe than sorry.

[danfmc TT Newbie]

Hello.
I'm Portuguese and I have a 1982 Suzuki DR 125S (SZ Model). When I bought it, the only mods it had were a bored cylinder (62mm diameter), a piston from an honda bike (I was unable to discover the model, I just know it was a 4 valve model and a 15mm gudgeon pin) and a new (stronger???) conrod matching the 15mm gudgeon pin. But now the piston oil ring just "glued" to the piston and the bike was burning the oil. The piston was wasted. Now I had the cylinder bored again (63mm), but I couldn't find another piston to replace the one I had, so I bought a custom made one. This problem is solved. But now I have another problem. The rear shock of my bike is blown and I need another shock absorber. But suzuki just don't sell those anymore, so I need to discover another rear shock to replace the one I have. Do you know if there is another motorcycle model I can get the shock absorver to replace mine? A cheap one if it's possible?

Regards.