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97 DR350 decomp and idle question

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Just purchased a 97 DR350. 2 questions about it.

1. I don't have to use the decomp lever to start up the bike. 2-3 square kicks and it starts right up. Believe me, I'm NOT complaining. I'm just wondering why I don't have to use the decomp lever. With my 91 DR350S, I could stand on the kick starter without it budging, until I used the decomp lever.

2. My idle has a "hang" in it. If it's a cold start, the hang will kill the engine. If it's a warm start, the engine will hang then continue to idle. After, oh, let's say 8-10 cycles, it'll hang again, then continue to idle. There's no signs of this hanging while riding the machine.

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Just purchased a 97 DR350. 2 questions about it.

1. I don't have to use the decomp lever to start up the bike. 2-3 square kicks and it starts right up.

Check the valve lash.

Valves that are set too tight will cause a loss of compression. If the valves are in spec then I would recommend a compression test.

1994-1999- Auto decompressor/Electric start models

Intake: .002 - .004 (inches)

Exhaust: .007 - .009 (inches)

Take the reading at TDC on the compression stroke with the engine cold

As for the idle issue, try the procedure listed in the above link.

If it still hangs, disassemble the carb and clean it thoroughly.

Every passage must be clear.

Replace any O rings that are questionable and check/set the float height to 14mm.

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Bob,

I have a follow up question.

I'm getting 2 diff. specs for the exhaust valve clearance.

For my DR350 off road, I've seen .007 - .009 AND .003 - .005.

Which one is right?? Thanks

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Bob,

I have a follow up question.

I'm getting 2 diff. specs for the exhaust valve clearance.

For my DR350 off road, I've seen .007 - .009 AND .003 - .005.

Which one is right?? Thanks

.007 - .009 For Electric start

.003 - .005. For Kick Start.

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it says right in the specs bob onit posted "auto decompresser"

Correct, auto decompressor came on the electric start models only.

The Off Road models have a manual decompressor so it's .003 -.005 (inches) for the exhaust valves.

I set mine on the loose end. (.005" )

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why the loose end? my 92 dr350's valves were all looser than spec. it was starting fine, never really that hard to get going, but i was swapping the tank and i figured i would check them out while i had it off.

i set both intake and exhaust valves on the tight end, but suddenly it's really hard to start the bike, hot or cold. also, i have a kind of stumble at 5-6k that wasn't there before. i was cruising at 80mph at 7k on the freeway last week before touching the engine with zero issues, suddenly i have a stumble. i can't help but think it has something to do with me messing with the valves.

should i go back and set the gap a little wider? like in the middle of the tolerances, or maybe even on the loose end? or do i have something else going on here?

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why the loose end? my 92 dr350's valves were all looser than spec. it was starting fine, never really that hard to get going, but i was swapping the tank and i figured i would check them out while i had it off.

i set both intake and exhaust valves on the tight end, but suddenly it's really hard to start the bike, hot or cold. also, i have a kind of stumble at 5-6k that wasn't there before.

I think you answered your own question. I adjust mine at the loose spec to avoid some of the issues you listed.

I would imagine that your valves are a little tighter than you may think if it's suddenly really hard to start.

Too tight and you can lose compression which will cause all kinds of problems.

Did you adjust them with the engine cold?

Edited by Bob Onit

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Did you adjust them with the engine cold?

of course. i'll get in there and loosen them up a bit and see if that helps.

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How high should the compression be on a 91 DR? Nobody kicks the engine (so it gets running) while pulling the lever right? The moves quite easily with or without holding the decomp, it just makes it a bit easier.

And could valve clearances cause the bike to be hard to start hot? Sometimes its 1st kick cold, sometimes more. But whenever hot, it usually takes a ton of kicking or waiting for 5-10mins.

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On both of my 92 DR350's I can barely push through the compression stroke without the decompression.

You do know how to use the lever, right? You pull it in and it should stay pulled in when you let go of it. Then you push the kick start lever down until the lever pops out. Next, let the kick starter back to the top and kick it all the way through.

Tight valves will definitely make the bike hard to start.

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I thought the post 94 models had auto decomp? I don't have a decompression lever, but mines a 99 with the magic button.

Yes, 94 and newer have an auto-decompression cam. The dirt models do come with a lever, but you don't need to use it.

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