What's wrong with my 94 Suzuki DT100?

[CWM1250057]

Okay, here's the problem. The motor will start fine, but then when I put it in gear it will either stall or won't go above 3000 rpm at wide open throttle. The carbs are CLEAN with new jets, I tried hooking a portable gas tank with fresh gas to it, checked the compression (120 on 1, 2, and 3 and 142 on 4), none of which worked. <br />I can't think of anything else, what could be my problem???<br />Any help would GREATLY be appreciated.<br />thanks,<br />Charlie

 

[JB]

Re: What's wrong with my 94 Suzuki DT100?

Part of your problem may be that you are too sure of what isn't wrong, CWM.<br /><br />You are probably making power with only three cylinders. The fourth cylinder may not be getting enough fuel or it isn't getting spark.<br /><br />Less likely, but possible, is that your ignition timing is not advancing with the throttle.<br /><br />What happens if you: pump the primer bulb while it is lugging at 3Krpm? What if you squirt fuel mix into the carb throats?<br /><br />Is the throttle opening all 4 throttle butterflies fully? Is the stator advancing all the way with the throttle?<br /><br />What happens if you disable each spark plug, one at a time, while at idle on the muffs?<br /><br />Let us know and we can get on to more detailed troubleshooting.

 

[CWM1250057]

Re: What's wrong with my 94 Suzuki DT100?

Okay, <br />Took it out again, this time I could get it up to just over 4k rpms. It wouldn't get much higher, but it was significantly faster than at 3k. <br />Pumping the primer bulb didn't do anything while lugging. <br />The throttle is opening all four carbs completely open. <br />I disabled each plug, one at a time, and I could hear spark from each of the wire. Cylinders 1 and 3 seemed to have a bigger impact on the engine idle. <br />Any ideas?<br /><br />Thanks for the help!<br />Charlie

 

[rodbolt]

Re: What's wrong with my 94 Suzuki DT100?

test your throttle valve assy. its called a TPS on the rest of the worlds stuff.<br /> your suzuki has an electronic timing advance, when did this problem start ? are you getting any alarm indications on the monitor ?<br /> the 142 cyl has me concerned.<br /> its rather high or the other 3 are rather low.<br /> if the spark wont advance to the correct spec it may be a bad sensor or sensor reference voltage.

 

[CWM1250057]

Re: What's wrong with my 94 Suzuki DT100?

I checked the throttle valve assembly today with the voltmeter and I couldn't get any resistance on one of the wires. The one that did have resistance showed lower than the shop manual specs. <br />It looks like this is at least part of my problem, I'll let you know how it turns out when I get the part in. <br />Thanks!!!<br />Charlie