Hi Everyone!
This marks the start of what I hope to be an active thread concerning the engine rebuild of my 98 Ninja (see my profile pic for the bike in question). When I got the bike, I also got a box of assorted parts, as the bike was not running. Due to the unknown history of the bike and possibly the mods that I had to do to get it running, I may have been damaging the engine. I'll start with a breakdown of the bike.
Mods:- Yoshimura slip on exhaust.
- K&N pod filters.
- Slightly larger than stock jets with adjustable mid range needles.
Like I said, not the best list of parts to
just get the bike running, but it's what I had at the time (as a poor college kid I was not going to go out and buy all new parts
.
Known Problems:- I know that I'm definitely burning oil. When I go to change the oil as well, I smell a good bit of gas with it.
- If I leave the bike alone for about a week and then go to start it, it can take an obscenely long time to start (40 seconds). When doing so it steps through three stages of starting.
- Starter running with no combustion.
- Starter running with some combustion that will not sustain if you let go of starter.
- Bike actually starting.
- Large throttle blips from idle after the bike has warmed up can use it to lug and kill the engine.
- Overall slower than expected RPM climb when revving.
I've been dealing with these issues for some time, but due to some life changes, I'll be moving across the country soon. I'd love to be able to get the bike mechanically sound and rely on it as a form of transportation for once I get there. Knowing that I'm burning oil, my intuition tells me that my rings may be fried. This should show up in a compression test right? Today I took a trip and went down to my local AutoZone and picked up a tester. Here's cylinder 1...
And cylinder 2...
If you can't see the pics I've attached them below as well because I haven't completely figured out this forum posting business works yet.
Now, this isn't as bad as I though it was going to be but I've been told that a difference of 30 psi between cylinders isn't good. Also, the low end limit for cylinder compression according to the EX250F service manual is 142psi. I'm a little close for comfort in my opinion. The next step for me is going to be draining fluids so I can pull the engine out and put it on a table. I'm by no means a mechanic, but if I can get this running a bit better than what it is currently I'll call it a win. Please feel free to leave suggestions and comments as I'm completely new to this kind of work and will be asking many questions in the first place. Whelp, here's goes nothing...