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View Full Version : What motor is this???


Power_Ram100
03-04-2005, 06:56 PM
I just bought a 85 Yamaha Tri Z with a Honda motor. The bike will only run if you spray starter fluid and compression start it. Even then it wont stay running for more than 1 min. Does anyone know what type of engine this is??? Also why compression start is the only way to get it running? The guy i bought it from says the CDI box is bad. Could the CDI box affect it that much?? Any help would be much appreciated.
Jeb
03-04-2005, 07:14 PM
Looks like a CR250 Mill to me. Mid 80s????
MTS
03-04-2005, 07:16 PM
yea looks like a cr250...but is that a powervalve?
Darius1502
03-04-2005, 07:24 PM
The reason the trike won't run longer than 1 minute is because your fuel pump is not working. Once it burns off the gas that you put in it then it stops.

Get a 1 liter Coke bottle...make a hole in the cap for a long gas line and then use some good electrical tape to seal it up. Wrap the tape around the cap and the line about 8 times. Then attach this to your carb.

IF the trike runs then you know its the pump. Thanks to Oranange Shee I learned this trick.
John mendolera
03-04-2005, 08:14 PM
Motor is a 1988-96 cr 250r,1984-87 had atac not hpp.If you get running should be one fast ride my 1990 cr250r went 76mph just clicking into 4th in the 1/8 mile it should top at 90's mph.
Oldshell4481
03-04-2005, 09:05 PM
can you say deathtrap???
Derrick Adams
03-04-2005, 09:30 PM
On the Tri-Z, the fuel pump is ran from engine vacuum. This is done by an insert into the side of the cylinder. I don't see that mod done to your engine. If it does turn out that you have no fuel, I would suggest getting a Tri-Z fuel pump and installing a vacuum port into your cylinder to run it.
Pistonhead
03-04-2005, 09:32 PM
Looks like a CR250 to me.
Lots_Of_Nothing
03-04-2005, 09:43 PM
Man them Tri-z guys will do anything to keep up with the Honda's.. Even use a Honda heart!
Apollo
03-04-2005, 09:55 PM
That is definetly an 88 or before CR250R engine.
Apollo
03-04-2005, 10:03 PM
I just looked at the left side again and the cylinder looks to be silver while black on the right side. Well any ways it is now an 88 to 91 CR250R engine in my opinion. In 92, Honda went to a different powervalve configuration that lasted until 2001. In 02, it has been electric to this day. I think the 95-96 CR250R engines are the all time best. Thick, nasty, wide spread of power that pulled from bottom to top. Awesome engines.