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DR350S new to me advice, starting and cooling

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I recently purchased a 1990 DR350S with around 9000 miles (to supplement my backcountry snowmobiling addiction with something to do in the summer) and I’m having an issue when starting it when it is cold(or hasn’t been running yet).  I can start the bike no problem with a 2nd gear bump start and then it will kick over first kick after its warmed up (hands off throttle and use decompression lever). I have cleaned the carb even though it was very clean when I opened it up as the previous owner drained the fuel regularly it seems after riding, so not much build up. I’ve read it seems every post on here that I can get my hands on but still can’t get an idea of what is going on as I’d like to be able to kick start it cold (I watched the original owner kick it over pretty easily). Is there anything other than the carb that could be cause of concern here.  The bike runs great once I get it going, idles fine and no weird noises while running, but is there anything special I should be looking for specifically? In turns of adjustment? Also since its air cooled is there anything I should watch out for while riding off trail and how to monitor temperature? I’m bringing it in this week to my local shop for a tune up and check everything out, but it’s just a beginner bike for me before I step up to something newer after I figure it all out.

 

Thanks in advance!

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These bikes are complicated to start

Steps to kick starting a dr 350

-turn on gas

-hold decompression lever and give the bike 5 easy kicks to prime the engine

-pull out choke

-press decomp lever, VERY slowly kick down untill the decomp lever pops out (if you keep the kick starter going down after the decomp pops out, restart)

-the kick starter should catch the gear at the top of its stroke (its needs a full stroke or else it wont hit the compression cycle so make sure the gear catches at the top of the stroke)

-give it a good hard kick. Throw your weight down on the kick start. Kicking it hard and fast is key. Lift foot up on kick starter immediatly after you kick it down. (When engine is warm, i can start it by kicking down while sitting on seat, but when engine is cold, i have to stand up on it and kick it)

- turn off choke when started and let engine warm up for a minute before riding

Also if the engine is hot, it might need some throttle assist when trying to start it, but if you need it when cold starting, it needs carb adjustments

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Also i have never heard any overheating problems with the DR350. I think the oil cooling system on top of the air cooling system does a pretty good job at keeping the tempurature down. I have also heard that the deep cooling fins on these bikes help with cooling as well

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I recently finished resurrecting my machine from a rebuild/tear-down, and it starts great now, but started out more-or-less like you describe  before the tear down last fall.  The old (stock) Mikuni was clean and looked fine, and everything was largely as you describe your bike, but it took 10-15 mins of kicking to get it going when it was cold.

 

Mine now starts great, even when cold (technique as described above by H-town enduro), but exactly which of the things i changed over the winter was most responsible for the improvement in starting i wish i could narrow down for you.  I installed/did the following all a the same time: a pumper carb (from Jesse), new performance cam (megacycle "medium"), valve springs, fresh valve adjustment, cleaned up head/piston of old carbon/gunk built-up, installed a new bottom end which would be largely irrelevant here except that the 95 bottom end included the different gearing for the kick starter, giving me a better ratio (turns the crank further than the stock 92 gearing did).  Once i got the initial fuel prime on the new setup, she now starts cold in a couple kicks, and hot in 1 kick.  Thank god...

 

but if you're doing as described above by H-town and its not working for you, then i'd suggest checking the obvious stuff to eliminate the easy ones:  make sure valves are in adjustment, good plug, clean carb with freely moving and right size jets, decomp mechanism adjusted properly (easy to check).   Some of those things shouldn't have a lot of effect on starting, but just making sure its all dialed-in before moving on to other solutions would probably be a good start. 

I think a lot of people have sold the kick-start DR's due to hard starting, and i don't blame them, but if dialed-in properly they start great.

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Mine starts with the decomp pulled in with 2 kicks when warm... 2 kicks with decomp pulled in with choke out when cold...

Don't let Monday ruin your Sunday!

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Any luck with this Screamingrhino?  I just got a 91 and I'm having the same issue.  I can bump start it no problem. I can turn it over warm in 1 kick, and every once in a while, if I'm lucky I'll turn it over when cold. Though, thats super rare and super frustrating.  This is my first bike and it's been kept up really well.  I have no reason to believe the owner put one over on me.  But yeah I'm at my wits end with this. I've changed out what looked like a brand new plug. Put in a new air fiter. Cleaned every electrical connector and put dielectric on them.  I drained the fuel and put fresh stuff in and I drained the float bowl.  It runs well...I just can't start it. 

 

One thing I notice people saying is that you need to have the kickstart grab at the very top of the stroke after going throught the decompression process.  Mine however will usually have a little bit of play in it and will grab between 1 and 2 oclock rather than at the very start.  Not sure if that is acceptable or not. 

 

Anyway, if you 've learned anything I'd appreciate you newbie insights. 

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Any luck with this Screamingrhino? I just got a 91 and I'm having the same issue. I can bump start it no problem. I can turn it over warm in 1 kick, and every once in a while, if I'm lucky I'll turn it over when cold. Though, thats super rare and super frustrating. This is my first bike and it's been kept up really well. I have no reason to believe the owner put one over on me. But yeah I'm at my wits end with this. I've changed out what looked like a brand new plug. Put in a new air fiter. Cleaned every electrical connector and put dielectric on them. I drained the fuel and put fresh stuff in and I drained the float bowl. It runs well...I just can't start it.

One thing I notice people saying is that you need to have the kickstart grab at the very top of the stroke after going throught the decompression process. Mine however will usually have a little bit of play in it and will grab between 1 and 2 oclock rather than at the very start. Not sure if that is acceptable or not.

Anyway, if you 've learned anything I'd appreciate you newbie insights.

Exactly! You explained it good. There can not be subtantial play in the kick start. It needs to catch on the very top of the stroke or there will not be enough momentum for the piston to pass through the compression stroke. It can be annoying having to keep re starting the decomp cycle to get the kick start in the right position but it is nessesary! The key is going VERY slow when you think the decomp lever is about to click out.

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Right on Htown. I'll be extra thoughtful to this. However I feel like if I kicked it over any slower to find TDC I'd be going in reverse.

I'm also noticing that people are saying to decompress it with fairly easy kicks. When the dude I bought it from showed me I felt like he was putting a lot behind it so I've been doing the same. Can you do the decompression strokes too hard thereby causing a problem?

I'm gonna go practice now. I'll let you guys know my success.

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So got it started. Here's what I noticed.

On prime things started to smell a whole lot like gasoline. I was kicking it a bunch without luck then switched the fuel to on. I wasn't sure if it was normal or not, the smell that is. Then I'm doing the compression process and I'm being mindful of where the kickstart engages when I'm ready to start it. Consistently it's grabbing further down the stroke like I said at like 2 o'clock . I'll try to post some pics.

Then it engages much closer to the top. I noted it, turned to my neighbor who was watching and said this is the kick. Sure enough it was. Is there a way to make it engage more consistently closer to the top? I really can't go any slower to find TDC.

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So got it started. Here's what I noticed.

On prime things started to smell a whole lot like gasoline. I was kicking it a bunch without luck then switched the fuel to on. I wasn't sure if it was normal or not, the smell that is. Then I'm doing the compression process and I'm being mindful of where the kickstart engages when I'm ready to start it. Consistently it's grabbing further down the stroke like I said at like 2 o'clock . I'll try to post some pics.

Then it engages much closer to the top. I noted it, turned to my neighbor who was watching and said this is the kick. Sure enough it was. Is there a way to make it engage more consistently closer to the top? I really can't go any slower to find TDC.

Sadly, i dont think there is. Mabey a valve adjustment or a decompression cable adjustment would effect it, but it sounds kinda risky. Like i said the key is to just kick very slow untill the decomp lever clicks out. If the decomp lever clicks out and your kickstart lever even goes a milimeter past, the kick start wont catch at the top of the stroke and you will wnd up at 2 oclock, and you will never be able to start in from 2 oclock unless the engine is already hot. Trust me, you will get the feel for it and land on 12 oclock more often as you practice. It took a while for me to get used to it but i did eventually and i usually get it on 12 oclock every time now. I know its weird but thats just how to DR's are.

But on the bright side, none of your friends are gona be able to start your bike lol

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FWIW '94 and newer models are easier to kick start. This is because of 1) the automatic compression release head and 2) a higher numerical gear ratio between a clutch basket and crankshaft so that a kick results in more crank shaft rotation then the earlier models. Also the kick start lever itself is about 2 inches shorter so you don't have to lift your leg up as high to kick it.

It would be prohibitively expensive to replace the cylinder head but it's fairly cheap to replace the clutch basket and starter lever. On one of my DR350s (a'96 SE chassis with '93 off-road motor) I retrofitted the later model clutch, crankshaft gear and starter lever and I find it much easier to start even with the manual de-comp head.

All that said, on a properly tuned bike its mostly technique not brute force.

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I never use the decomp lever. From cold it's usually about 1-3 kicks. Wasn't anywhere like this when I first bought the bike though. Adjusted valves, changed plug, Raptor petcock, a real carb clean (not just sprayed with cleaner), Dynojet kit, float bowl adjusted.

Starts fairly easy. If I'm riding and stall and flood it, just turn off the gas, lean bike right down, then I sometimes use the decomp and give it a few cycles to clear out. Then it almost always starts the next REAL kick.

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I never use the decomp lever.

Not really a good idea. Might seem like the "manly" thing to do but there are numerous reports of broken DR350 cases on ADV Rider from not using the de-comp.

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So I finally was able to get the stupid thing tstart without bump starting (luckily right before my first trip as I was unloading from my truck).  I find my decomp lever is pretty useless when trying to find where to kickstart it, like everyone says its a learned ability to start the bike.  Once I found out how to do it I can start it usually within five to six kick after turning the gas on.  It does take a good sturdy kick to get it to turn over.  I cleaned the carb, replaced the air filter and cleaned the airbox.  I think the bike definately needs to be tuned up but this is an experiment for me to see if my buddies and I like will get into the sport.....which so far I haven't had a grin on my face like this other then backcountry snowmobiling. My only concern now is the fact that there is a little smoke coming from the seal from where the muffler and header pipe connect (at startup), it seems minimal but I'm paranoid with mechanical issues. 

 

I've found no magic tricks with starting these bikes, it seems to be the nature of the beast and each is unique.

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Not really a good idea. Might seem like the "manly" thing to do but there are numerous reports of broken DR350 cases on ADV Rider from not using the de-comp.

No not trying to be manly. Maybe I just don't understand how to use it, but aren't you guys just using it to find TDC? Then you let go and give it a kick? The bike doesn't start with the decomp lever pulled in. I honestly don't see a point if all it's for is finding TDC, I can get there without beating the shit out of the kick start, then just a good solid kick.

I've seen the pics of damaged cases. I know I'm not kicking mine hard enough to bust the casting around the kick start.

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No not trying to be manly. Maybe I just don't understand how to use it, but aren't you guys just using it to find TDC? Then you let go and give it a kick? The bike doesn't start with the decomp lever pulled in. I honestly don't see a point if all it's for is finding TDC, I can get there without beating the shit out of the kick start, then just a good solid kick.

I've seen the pics of damaged cases. I know I'm not kicking mine hard enough to bust the casting around the kick start.

Yes it's just to locate the correct crankshaft position. Don't know that it's TDC tho. If you can reliably find that then I agree it's not necessary. Sure makes it easy.

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Interesting so I can just push through slow to find the top of the stroke and that's it. Why the heck do you need to do 5-10 kicks with the decomp down? It's gotta serve another purpose

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Sometimes if I flood my bike or have a hard time I'll turn off the fuel, pull the decomp and kick it a few times to clear it out. Then it usually starts next kick.

I honestly don't know what the big deal is starting these bikes though. I'll admit it's harder than my old 2 stroke Gas Gas but just needing a little more muscle on the kick is all it takes and it usually goes 1-2 kicks.

Honestly if it's really that hard to start, do some work on it like I mentioned before. Half those things are free to do anyways.

- Adjust valves, you feel a huge difference in compression right away if they are too tight.

- Incorrect float height also causes hard starts or flooding.

- A real carb clean, not just a spray clean. Pull jets, soak them in cleaner and agitate. If you have access to an ultrasonic cleaner somehow use that, I did and my jets and pilot circuit came out mint. Use copper wire to clear passages.

- Hand off the throttle!! If the above are correct you shouldn't need any.

If it still isn't starting easy, buy a new petcock from a Raptor. In fact you should probably do that anyways, that factory one is absolute junk.

Hopefully this saves someone's right leg an excessive work out.

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Interesting so I can just push through slow to find the top of the stroke and that's it. Why the heck do you need to do 5-10 kicks with the decomp down? It's gotta serve another purpose

this can flood it.

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