Hello i have a 1994 trx300 utility 4wheeler and i can not get it to spark it has been parked for over 3 years because it has been broke and i have started to restore it. i have replaced all the wiring. my voltage regulator was bad so i took one off a 86 trx250 i have and mounted it. i was having problems with it cranking with the start button it wouldnt do anything unless jumped straight to the solinoid. i got that resolved but i still have no spark. i have a manual for it and i have tested all parts that i could including regulator, coil, plug, i have also bypassed the off switch so it was just on run and nothing. i am thinking my cdi box is bad. is there anything i could be overlooking on this deal. thanks in advance.

 

 

sorry about the blank post. Sounds like you got a mess. Go back to the basics and check for all the proper restistances AT the cdi unit. If that's all good try unplugging and reconnecting the unit. If you still have no spark and haven't found any weirdness, try a cdi box. If possible, try a known good one before you spend your hard earned. As you have no way of testing it, you never know for sure that's the problem til you try a known good one and it works.

 

well since this post i bought a 02 400ex and tonight i got my 94 trx300 to spark it is a very weak spark though. the problem was the alarm unit i had one off my 86 trx250 so i swapped them and it sparked. i think my pulse generator is bad or going bad cuz when crankin with the plug out to see spark it will be weak spark then hit good a few times then no spark while still turning over after like 3 sec. it stops sparking. does this sound like the pulse gen at all. also could it be the stator?

 

hmm... that's interesting. I know that alarm unit is there next to the cdi unit but I'm not sure offhand what it does. Seems to me I checked a couple times over the years and came to the conclusion it isn't related to ignition. Anyway, I've never seen the alarm unit fail. Your symptom doesn't sound like pulse generators, they either fail outright, or can be intermittent, that is will fail when the machine gets hot. Some models are prone to this but not 300's, don't think I've ever replaced them. You can check them via resistance, or if you have a good meter, check them for voltage while the engine is spinning. They have a very small voltage output tho, as low as 2 volts. Your symptoms have "bad cdi box" written all over them. I have seen them fail in that manner of inconsistant spark at cranking speeds.

 

yea i have no clue what changed but when i put the new alarm unit on it sparked and that was a first in a long time. i have a cdi from my 86 trx250 and an extra cdi from my 400ex because it has a rev kit on it. could either one of these work or does it have to be from a 300? i am about to go out and see if i can get any farther on this. thank you for your help so far. i want to get this thing running before winter so i can use it for hunting. thanks again.

 

Well the 250 & 400 cdi didnt work. i have a chance to get one for a 300ex would that work or does it need to be for a utility 300? i have this same question in a reply i did in another post but i need to figgure out an awnser. anyone with info please help.

 

I don't think so. The 300 you have is a dc-cdi ignition, the 300ex is an ac-cdi I believe. When it comes to ignition units, it's really best to have the right thing. I think over the years the plain trx300 used two different ones. Not exactly sure what the cut off is, but I think it's 94 or 95. Anyway, they're all dc-cdi. I'm not sure what the difference is. I know Honda changed their suppliers about that time from (I think) ND to Phillips. Had quite a few problems with the first year Phillips boxes. The most common complaint was hard starting, or wouldn't start til you let up on the starter button. You could actually observe this on a spark test. No spark til you let up on the button, then it let out a big fat one or two. I also have seen some where spark would just kind of come and go. You can probably find the mfg name on the box. Check the price of a new one, I don't think they're THAT high for a cdi box.

 

Well i got the cdi box bought it new it runs now a little rough but hey it runs i need to rejet carb for exhaust and do some other stuff like find jar of bolts for everything to put it together. thanks for your help.