1990 Suzuki DR350 Rebuild

[Tekime]

Damn it!

Just checked and you're right, she's totally out of coolant. I can just add that to the oil hole thingie right?

Haha, yeah she's air cooled... checked over the cam timing and pretty dern sure it's right but I'm pulling the valve cover again anyway so I'll pay close attention there. These DR's do get hot.. but this is crazy hot.

Anything else come to mind that might cause it??

[Paul_E_D]

combustion fire going right out the valves... But I haven't ever measured temps on my air cooled bikes. What is normal? I've never even heard of measuring that.

[csmutty]

Oh yeah...

How the hell are you measuring engine temp on an air cooled bike? Oil temp?

[Paul_E_D]

Oh yeah...

How the hell are you measuring engine temp on an air cooled bike? Oil temp?

THat is what threw me off!!!

[csmutty]

THat is what threw me off!!!

I'm not letting you out off the hook that easy...

[Tekime]

It's a washer type sensor that replaces the spark plug washer, and connects to the Vapor dash. I've also zapped the head with my laser thermometer and get the same number within a few degrees.

I've read other DR owners seeing temps in the 350F range but I think that might have been with an oil temp sensor mounted on the dipstick? They're notoriously hot but honestly no idea what's TOO hot... 415 seems insane.

[carsick]

Most air cooled advice I've heard is you don't want to check the temp under hot/slow/high load conditions, because it would scare you. It would take a mighty radiator cap to get the coolant up to 415 (about 250 psi)... and if that's an oil temp, RIP lil' DR. I'm guessing this is one of those sensors that replaces the spark plug washer, which is a hot damn place.




edit- slow post, yup.

[Kurlon]

Wait, it replaces the spark plug crush gasket? This seems like a formula for a bad plan...

Some reading that might be useful: TheSamba.com :: Vanagon - View topic - Aircooled Cylinder Head Temp. Sensor

Is it a compensated thermocouple? If not, it's cold out, that might 'splain the temp you're seeing.

100% plug'n'play aftermarket ECU for our cars for under $1000 - Page 9 - Rennlist Discussion Forums <- Suggests air cooled Porche in race conditions, measuring plug temp this way can see up to 400F.

[Paul_E_D]

Forget it. The bike is fine. Take that sensor off and ride it.

[carsick]

Imagine if we all had jobs and couldn't find the time to help poor Tekime.

[Paul_E_D]

Jobs. THat's funny

[csmutty]

It's a snow day. Screw off lol.

[Tekime]

Work indeed... my kiddo has the day off so she's doing art and watching YouTube, I'm cooking her food and writing code, my cats are staring at me, I've had 3 meetings today and one more to go, so obviously I'm squeezing some forum time in 'cuz I don't have enough to do already

Working at home has its benefits and snow days is not one of them...

Most air cooled advice I've heard is you don't want to check the temp under hot/slow/high load conditions, because it would scare you. It would take a mighty radiator cap to get the coolant up to 415 (about 250 psi)... and if that's an oil temp, RIP lil' DR. I'm guessing this is one of those sensors that replaces the spark plug washer, which is a hot damn place.

edit- slow post, yup.

Well my experience confirms that... scary

Wait, it replaces the spark plug crush gasket? This seems like a formula for a bad plan...

Some reading that might be useful: TheSamba.com :: Vanagon - View topic - Aircooled Cylinder Head Temp. Sensor

Is it a compensated thermocouple? If not, it's cold out, that might 'splain the temp you're seeing.

100% plug'n'play aftermarket ECU for our cars for under $1000 - Page 9 - Rennlist Discussion Forums <- Suggests air cooled Porche in race conditions, measuring plug temp this way can see up to 400F.

Compensated thermowhattle? I'll definitely be reading those links.. BUT the sensor itself is a washer, replaces the crush gasket and is the same thickness. It tweaked me out a bit when I realized what I was about to do but went ahead with it. The I/D on the provided washer sensor was slightly small so I had to grind it a bit. Not the prettiest solution but it seems to run exactly the same and temps seem accurate...

I believe I could rewire it to a different type of sensor later on, I'm not a big fan of this setup but it is doing its job.

Forget it. The bike is fine. Take that sensor off and ride it.

But I like the data!

[TheIglu]

It's a snow day. Screw off lol.

Ah, you are one of those "optional" employees.

[csmutty]

Ah, you are one of those "optional" employees.

I went in for 7am. Closed the plant down by 10am.

[TheIglu]

Optional plant?

[csmutty]

Optional plant?

Depends on the state. It's still not an optional plant in CT.

[Tekime]

Went with the 40/140 jets (from 37.5/132.5) and and it smoothed out a lot. Temps haven't gone over 350 since - it seems a bit cooler, not heating up as fast either, but I haven't ridden it hard yet .

Now I have to sort out the clutch. Adjusted to the max and still doesn't fully disengage. Improves when hot but still a real bitch, drags enough to make walking the bike backwards a real chore not to mention finding neutral. Swapped the springs with a slightly shorter set I had but made zero difference. New clutch cable so I don't think that's the issue. I have a spare clutch so I'm hoping I can inspect/use parts as needed and don't need to replace it at this time.. gonna pull it all out again and measure/clean/soak the plates and check the basket over.

[Tekime]

Swapped the clutch out and noticed the clutch basket nut was way too tight. Torqued it to spec, threw the other set of plates in and it's like night and day! Slips right into neutral and clutch action is super tight.

Not sure if it's the plates or what but she bites hard and fast. Still needs a he-man grip to work the clutch lever but not so bad now that I don't have to squash it down to the bars.

Damn, I've almost run out of things to fix! Bit more tuning & cleanup, minor stuff, but I guess it's time to get some street kit and start prettying her up.

Fun fact: I can now swap the clutch on a DR in about 30minutes

[typeone]

other than something else more entailed going on...

did you lube the new clutch cable really well? like soaked through with proper cable lube using a tool? might help, i've had new cables that were a little dry causing shitty feel. how you route the cable (and it's length) can be important too.

also wondering if you can extend the clutch arm a bit, that was the hot ticket on the Husky 250/300's to ease the pull. usually doesn't take much length to improve the feel dramatically.

[Tekime]

other than something else more entailed going on...

did you lube the new clutch cable really well? like soaked through with proper cable lube using a tool? might help, i've had new cables that were a little dry causing shitty feel. how you route the cable (and it's length) can be important too.

Pretty sure it's a dry/sealed cable so I haven't attempted to lube anything. I'm 95% sure the routing is correct, comparing to service manual and pics I've found.

I did switch back to the slightly longer springs, which I'm assuming are heavier than stock, but I don't really know where they came from. They definitely bite.

also wondering if you can extend the clutch arm a bit, that was the hot ticket on the Husky 250/300's to ease the pull. usually doesn't take much length to improve the feel dramatically.

Hmmm.... I like your thinking. The clutch arm does look slightly bent upward and quite possibly bent over time.

Before "fixing" the clutch I needed the full arm radius and max adjustment to release the clutch. That limited the angle of the arm relative to the clutch. Now, I have some room to play with, I might try at a steeper angle just to see if it helps.

Have another clutch arm kicking around - time to compare the two and/or order a new OEM or find/fab something longer.

Cool. Thanks!

[Tekime]

Hahaha... I'm a dumbass. Apparently the Motion Pro cable is supposed to be lubed.

[typeone]

i love beer. jus sayin' .. .

[Tekime]

Well she's properly lubed now. Smoother but still a hard pull... progress

Side note: I'm also wondering if that overtight clutch basket nut was contributing to the heat. The jetting seemed to help, but it actually seems even cooler now after the clutch job. Imagine all the friction from the basket being so tight couldn't have made it any cooler anyway.

[Tekime]

Procycle street kit + battery kit should be here by Wednesday, counting the days! Spoke with Town Hall and things are looking good for registering her as a street bike without much issue. Was pretty worried about getting a new VIN and all this stuff.. but based on my conversation it's going to be extremely easy and I can register as an antique so no inspection required.

Just happened to pick something up over the weekend too:



Couldn't pass it up for $350 - fix her up at best, parts bike at worst. Suspension is well abused, some rust, missing a few bits, but turns over, sounds like compression and shifts through the gears. Parts are getting rare & more valuable for these bikes so it was well worth the cash.

Meanwhile, I repacked/repainted/rebadged the old Big Gun and installed an arrester. Installed some new grips, brush guards and a few other details. And repainted the gas tank (again). SO CLOSE.