DRR 90CC Shuting off

[nuttystang]

Need a little help we have a 07 DRR 90CC Air Cooled we run on 1.5 mile track mx we can run 2 or 3 laps and the bike will shut off and then i have to kick it several times to start it then it will run maybe 1/2 to 1 lap and shut off again we are running the stock cylinder and pipe 24mm kelhin carb, uni filter, any help would be great

Also, the starter gears were taken out when I bought the quad what do i need to do to put electric start back on it starter and wiring are there, I have a battery, what gears etc. do i need and is this a good idea my daughter can not kick start it yet

[bulldogfallon]

Sounds like you may be running out of fuel....Does your machine have a fancy fuel hose vent on the gas cap?

[nuttystang]

I have a hose on the gas cap that goes down the handle bars it is about 12" long

[greenmachine70]

sounds like your coil is going bad. My nephews just did the same exact problem. Remove the plug cap from the coil wire & see if it is corroded. His was & it apparently caused the coil to begin shorting out until it went bad.
New coil & problem is gone.

BTW, thanks for the deal on the pipe!

[nuttystang]

We put a coil and plug cap on it about 3 or 4 weeks ago, but I am gonna try everything just need some direction, we checked the fuel line form the pet cock to the filter and the fuel come out real slow so we are gonna pull that apart tonight and check the compression.

No prob on the pipe

[mudder700]

I have starter gears that I will give you if you want to pay shipping, let me know your address...Kurt

[#404's Dad]

I have had two bikes do very similar things and both had different issues.

Try closing the gap up on your spark plug and see if that helps, I have one bike that won't run right unless the gap is tight.

After this happens pull your carb off and see if the intake tube is wet or flooded, We had one of our 08s with the float level set to high letting fuel run into the intake and and when he would turn or hit a bump just right it would dump all that extra fuel in the motor and kill it.

Just a couple things you can try, may not help but they might too.

Corey

[humboldt hills]

CAn't believe no one has suggested checking compression?
Once the engine warms up, you will lose power and die if you ar elow on compression.
Then it dies alot sooner once its warmed up.

[nuttystang]

I think we figured it out we pulled the head and cylinder off the piston had a white spot in it and was clean on the inside, the cylinder is scored and the rings are melted to the piston, we did a compression check and had 75 on it so we are gonna run a 125 main and 50 jet to see that helps we are located here in florida thanks guys :eek:

[bulldogfallon]

Running lean can cause the excess heat and the damage could hurt your compression.

Compression would lead to hard starting from the get go though.

125 could be a big jet unless the quad is modded.

I would do a leak down test to see if you have an air leak causing the lean condition which may be the problem which caused the compression issue.

Have you checked the intake boot for small cracks? This is an issue that is a frequent culpret

Don't confuse the result with the cause.....lean and compression

[greenmachine70]

Scoaring randomly around the cylinder is from lack of lubrication.

Scoaring on the exhaust port side mainly is from running lean, possibly caused by an air leak.

My air cooled 07 DRX90 has the Koso Reeds/Intake, a Keihin PE24 carb & it needed a 120 main to run.
If your compression is low, run a 1 size hotter plug.

[nuttystang]

we have not down a leak down test yet we just got it back together tonight and fired it over it took about 10 kicks to start it, i will do a leak down on it this weekend and we bumped the jet to 125 main so we will perform the test and see what that does then run it and I will up date yall in a day or so man everybody on here is great, i really appericate the help, thanks to everyone..

[bulldogfallon]

75 psi is very low...Sounsd like you need a rebuild or have a leak somewhere..

[greenmachine70]

Originally posted by bulldogfallon
75 psi is very low...Sounsd like you need a rebuild or have a leak somewhere..
agreed for sure.
Also you stated the rings were melted to the piston, in my shop that is basically catastrophic failure.
I beleive you will need a complete top end, cylinder & piston at the least. Once scoaring that bad develops you are out of luck.
Probably cheapest to bore the cylinder out to 54mm(if possible) & upsize the piston.
Let us know how it turns out.

[ecmini1]

Originally posted by greenmachine70
sounds like your coil is going bad. My nephews just did the same exact problem. Remove the plug cap from the coil wire & see if it is corroded. His was & it apparently caused the coil to begin shorting out until it went bad.
New coil & problem is gone.

BTW, thanks for the deal on the pipe!


Seems like I remember that. :D


For vacumn leaks we use a smoke tester. It fills the eng. with white smoke to detect a air leak. Very handy tool.

LIke bulldog stated ck intake for cracks and also ck crank seals.

[nuttystang]

we got it back together and ran it for about 20 min and it died and made a noise like it was starving for fuel, so and would not start back up so i guess it time for a rebuild with crank seals and intake boot, cylinder and another new piston and rings, plug is blackish grey can take pic if needed, we installed a 130 main jet

[nuttystang]

i think we have found the piston killer i pulled the carb boot off and it has several dry rot cracks in it and the fan has some broken blades so going to replace that stuff and hopefully be able to race more than 5 laps, would like to thank everyone for there help and kindness here

thanks to mudder for the gears great guy
and also g-force gary and dusty at cheaters have spoke to dusty several times all of the guys here are great :) :) :) :)

[miniquad]

Make sure you check or replace the crank seals, this is an overlooked problem that I have seen several times cause what you have been describing. Good luck with your rebuild.

[nuttystang]

ok we have put this thing back together and it sounds good on the bench but when ever she gets on it and rides she comes out the hole it breaks up and all the way to wide open, we put a hetrick free flow head on it and a 52 mm piston, and crank seals and replaced all gaskets put new carb boot on, gas cap is venting great we had it at the track and we had a 130 jet for the main and it would not go anywhere so we bumped it up to a 135 and would run but break up we moved the clip to the middle on the needle any pointers would be cool, thanks

[bulldogfallon]

Have you tried asking the company you bought the parts from?

If they sold you the head and parts then they may know how to make it run with that set up?

[nuttystang]

bought used i asked the guy and he said he had a 28 mm carb and 138 main jet on it. does the 28mm carb make that much of a difference over the 24mm

[bulldogfallon]

24mm is better for MX.

You are probably too rich if it is breaking up.


You also need to make sure to use a new plug...a fouled plug will not make it easy to tune.

You may want to lean out your needle to see if it helps.

If you have no idea where you should be then try extreme changes and that usually tells if you are going in the right direction.

Run the needle clip at the highest and lowest position to see what happens.

[nuttystang]

i will try it this weekend and see where it ends up i will update u guys, thanks 4 the help..

[tireman43]

We are having a HUGE issue with our 28mm carb. It has the same problem you are describing and I have went both up and down with jets and it only gets worse. I am running a 130 main right now and it seems to work good if my daughter can hold it wide open but that isn't always the case with MX racing. I have been replacing the plug every moto and it is working o.kay. A new 24mm carb should be on it before the next race to hopefully resolve the problem.

I believe the 28mm makes more power on a dyno and when wide open all the time, but for MX it is just too much fuel, and the power goes unused.

Kevin

[03bill]

I have been watching this thread for a couple of days now and wanted to let you know what I found. I have been working on Kasea's for about 3 years now and no most the ins and outs with the motors, carbs, and electrical.

The one thing I can say about these minis is that the electrical systems are junk. I have a young man who races with us that rides a DRR and I do all of his work on his bike. His bike would run and then die like the original post here. After trouble shooting it for about 3 days we figured out that a relay had gone bad. We switched it out and it ran good for the next race and started doing it again. Out of frustration I decided to remove the entire wiring harness and just run the cdi box and coil. Since it has been removed we have had no problems other than the kick start spring wears out rather quickly. This is common on every mini I have ever worked on.

[nuttystang]

Thanks 03 I think I am going to remove the wiring from it and just run the wiring off the cdi box it just gets real frustrating thanks for the help

[bulldogfallon]

A bad ground be a pain to deal with and find....

One of the first things we do is remove the harness..


If you do make sure you ground the engine too...


We just built a 90 and didn't do so and it ran terrible....1 short ground wire and she took off like a rocket.

[03bill]

If you need help with it, just PM me and I will give you my number. It is actually pretty easy, it is just a little overwelming the first time.

[bulldogfallon]

Here is a brief to the point wire layout:


If someone has anything to add I will be glad to add any tips to the page as well....

http://yhst-17379619078614.stores.yahoo.net/wihaby.html (http://)

[coffing918]

IF YOU STILL HAVE THE STOCK KILL SWITCH DISCONNECT IT THEN SEE HOW IT RUNS, THEN BUY AN AFTERMARKET ONE, MY SONS HAD THE SAME PROBLEM EVERYONE THOUGHT IT WAS COMPRESSION AND IT TURNED OUT TO BE JUST THE STOCK KILL SWITCH, THE BUTTON INSIDE FLUTTERS,, I KNOW IT SOUNDS STUPID BUT JUST TRY IT IF YOU STILL HAVE THE STOCK ONE. I COULD BE DEAD WRONG BUT THAT IS WHAT WAS WRONG WITH MY SONS DRX 50

___________________
#918 JULIAN COFFING
#799 NICK MAJOR

[nuttystang]

I am going to remove the kill switch and see how it runs tommorrow and i will update everybody. thanks

[mmsoup]

Have an 08 70 and an 08 90 and we had fuel line cracks causing the 70 to do the same basic thing you are describing. No apparent motor damage though. We caught it fairly quickly

[nuttystang]

we bypassed the wiring harness and have not run it any yet but i am going to run it on sunday the 29th it has been raining every night here in sunny florida.