Author Topic: Dt 200 compression  (Read 717 times)

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Offline Benno81

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Dt 200 compression
« on: August 19, 2017, 08:20:06 PM »
Have a 96 dt200r that I brought in bits and have been putting back together
Have rebuilt the engine fresh bore n home and pro x piston gaskets etc
Ok so bike started straight up ran real well but I've gone to start it again the next day and wouldn't fire so I took out plug and poured a small amount of fuel and bang starts first kick.so I cleaned out carby and put back together.
Bike started couple hours after this but if I leave it overnight won't start unless fuel down plug hole.
I brought a compression tester today and with motor cold and throttle wide open I get around 125psi
It sounds bit low too me but have read that 110 is min u want for dt200 due to its low cr
Is this correct? And if so where else should I look for the cold start problem?
Thanks in advance ben

Offline mikeyvet

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Re: Dt 200 compression
« Reply #1 on: August 20, 2017, 07:03:21 PM »
125psi on a cold DT200 won't stop it from firing up, and I would be happy enough with that.

The mixture at start up is too lean.

I had a problem with poor cold start a couple of weeks ago, the problem was a blocked channel in the float bowl of the carb, I had cleaned the body of the carb twice already but overlooked the float bowl. The enricher (choke) inlet tube runs down a channel in the float bowl with a little jet at the bottom and that tiny jet was blocked.

Assuming the bike idles and runs OK when warm I'd be looking at that carb again.

Failing that I'd be looking for a vacuum leak, but they tend to make the bike idle too fast. Spray WD-40 around the carb inlet and look for a change in idle revs. The breather for the crankcases is a clear tube on the top right side of the motor, listen for a hiss there or put some spit on your finger and then into the end of the tube, if it gets sucked up the right crank seal is no good. I don't have an easy test for the left crank seal as you can't get to it while the engine is running.

Offline Benno81

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Re: Dt 200 compression
« Reply #2 on: September 03, 2017, 07:54:56 AM »
Ok so I took carb off and the hole in the bowl was clogged so I blew it out and put carb back on
Now starts first kick cold or hot
Thanks a lot for your help the choke hole in the bowl is easily missed

Offline mikeyvet

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Re: Dt 200 compression
« Reply #3 on: September 03, 2017, 11:09:44 AM »
Coolio!

Did you check the other channel in the float bowl for the power jet? (Yeah was blocked on my one too)