93 xrt 225 yamaha

[cebu]

i'm having a problem with the engine going from idle past 1500 rpms , it will stall when the throttle is pushed forward . it will idle in gear , and if i pull the throttle out to neutrel and rev it up ,then put it in gear before the rpms die down i can get it to go past slow speed all the way to full throttle and run fine .its only at slow speeds from 1100 -1800 or so rpms it will die . so far i have changed the fuel filter /water sep. , drained the carbs to check for water or dirt , and replaced the throttle sensor ,changed the spark plugs ,and checked the wires ,and the compression , all cylinders around 120. any one have this problem before ?

 

[Ray Neudecker]

Re: 93 xrt 225 yamaha

That is a fairly complex engine and there are several things which can cause this problem. The carbs need to be disassembled and thorghly cleand and rebuilt with new bowl gaskets. The fuel pumps may need to be replaced.
If you are not running premium gas, the knock sensor can cause this.

 

[cebu]

Re: 93 xrt 225 yamaha

the knock sensor ? i did check it by hooking up a ohm meter to it and taping on it i did get a reading , i did have the carbs apart before and they looked pretty clean , the engine is 14 years old so rebuilding them is probably a good idea as well as new fuel pumps , but what is it that wears out in the carbs ? it seems like mostly jets ,and if they are not clogged should'nt they be fine ? well thanks for the advice .i'm going to start with the fuel pumps 1st and go from there ,in order yo see which repair fixes the problem.

 

[Ray Neudecker]

Re: 93 xrt 225 yamaha

The only real wear in the carbs will normally be the needles. The bowl gaskets will also start to wear and put fine pieces of metal into the carbs causing the needles to stick. The main other problem is with passages clogging.
The passages are the main purpose of cleaning.

 

[cebu]

Re: 93 xrt 225 yamaha

i remember on the 1970 dirt bikes i used to have ,the carbs had a needlefor the throttle that slid up and down in the main jet ,that could be ajusted , but these carbs look like only jets and passage ways , thats why after taking them apart and not seeing any dirt in the bowl or jets , i suspected that the problem was with something else i have ordered fuel pumps , i'll see what that does and take another look at the carbs