GSXR Wont start (different from bellow)

[James87]

I purchased a 98 GSXR 600 that was full race prep yesterday. I got the bike home and took it around the block, other than not wanting to idle it ran fine and had great power throughout the rpm range.
The previous owner added an LED tail and a small headlamp to make it street legal.

Well today I pulled the headlamp and LED tails off, then pulled the tail section to give it a few coats of rattle can goodness.

At that point I tried to start the bike and and it turns over fine but doesn't actually start. I charged the battery up and its still a no go :?

I went over all wires and grounds with a fine tooth comb, as this has to be an electrical issue. It doesn't seem to be getting spark, but I haven't confirmed this yet.

Thanks in advance for any help as any suggestions would be greatly appreciated.

[rybo]

Start with the simple stuff -

Kill switch?

Kickstand Jumper?

then confirm spark by pulling a plug (or two)

[James87]

rybo, Thanks for the fast response.

I checked the kickstand jumper and it is in working order.

Kill switch is also operational. also, whats the best way to actually test the switch?

I pulled all four plug caps (1 at a time) and used a spare plug to test, and all had very good spark.

A side note: 3 of the 4 plug boots shocked the daylights out of me as I inserted the spare plug. The key was off and I had not tried to start in at least 20 minutes. Is this normal?

Thanks again

[James87]

Update: After letting the bike sit for awhile, I tried again and got it to start.
However, the bike just didn't sound right. Also, I had to keep the bike at about 5k RPM's to keep it running. Once I let off the throttle it died immediately. On a hunch I decided to check the primaries for heat. 3 were scorching hot and one was stone cold (cylinder #2 from L to R as sitting on the bike).

I confirmed this cylinder to get spark earlier, so I'm at a loss.

Ill recheck for spark again in a bit. In the mean time if you have any suggestions I'd appreciate it.

Thank you kindly

[TRK]

Recheck for spark.
Check your plugs to see if they are fouled. New plugs couldnt hurt.


Check compression.
Leak down test.

[Clarkie]

Air, spark, fuel. If one is missing our low no vroom vroom :wink:

[rybo]

How about clogged jets in the #2 carb?

[James87]

Scott, I think that is the issue.

I re-confirmed spark in the #2 cylinder and it was very strong. I also went ahead and pulled all 4 plugs to check there condition.. Well all 4 were black and sooty. Also, They smelled like really old fuel, a very sweet kind of smell.

So I think its time to get into the carbs.

TRK, Thanks for recommending the compression test I never thought to do that. I Will be checking that soon. How is the leakdown test performed?

[rybo]

Cleaning up the carbs on any bike that's been sitting for a while is almost mandatory.

Leakdown test is a bit like a compression test but holds at compression to see if there are any slow leaks (like a valve not seating properly)

[jgixxer1]

Coming from dirtbikes, sounds like clogged pilot jets. And definitely new gas before you try again.

[marty]

Also, They smelled like really old fuel, a very sweet kind of smell.



Sarcastic sweet or actual sweet? If actual sweet, does any of the oil look milky? If sarcastic sweet, I concur , old gas will make your nose hairs curl :lol:

[James87]

Well I pulled the carbs and had a peek inside. All jets, in all four carb bodies were completely clogged. So I stripped them down one by one and cleaned them using compressed air. I did not remove the plunger assembly, but verified that they do move freely.

I also removed the fuel sending unit from the tank to check fuel filter condition, And it was nice and clean. then I went ahead and cleaned out the airbox and blew out the air filter.

At this point I put everything back together and she fired up nicely.

However, now my idle is alllllllllll over the place. Initially, it stayed around 3k rPM and jumped up and down agood 1k - 2k. after a minute or two it would drop and almost die. But as soon as I touch the throttle it starts screaming again.

jgixxer1, I wish I would have seen your post earlier as I reused the old fuel :oops: what was I thinking!?

marty, It actually had a sweet smell to it, A pungent sweet smell. I haven't drained any oil as of yet, but looking into the sight hole, Its a dark brownish, black color. Note to self: Change oil

[James87]

I did notice one thing I have to ask about. The 2 "inside" carbs had a richer main jet than the outer ones. Is this normal?

Sorry this has gone on as long as it has, but I really do appreciate all of the input you guys are giving. Thank you kindly.

[marty]

The joys of an older bike! :lol: I'm just in the middle of splitting cases because my 125 was burning water. A leak down and compression tester for older bikes will be well used tools. Snap on, mac, etc all make nice ones but a nice OTC or the like will work great for as little as you will use it. I can't say for sure but Tool Zone on I25 always has a nice assortment of well priced automotive tools.

Another must for older bikes is a service manual. Haynes and Clymer are nice but a factory one is the jam!

[James87]

lol you said it marty, But I do enjoy getting my hands dirty :lol:

I have a compression tester and a shop manual for the bike, so I have some figures for you and there not pretty.

CYL #1: 125 PSI
CYL #2: 120 PSI
CYL #3: 115 PSI
CYL #4: 120 PSI

According to the manual, Standard is 156 - 213 PSI with no more of a difference than 28 PSI.

I suppose a rebuild is in order. Any of you shop guys out there feel free to chime in with a quote if at all possible.

marty, would that be an Aprilia RS 125? Ive always wanted a 2 smoker to throw down on.

[marty]

marty, would that be an Aprilia RS 125? Ive always wanted a 2 smoker to throw down on.

Honda RS 125. I wish I had the cash for a RSW 125 Ape :D

Give Bart a call over at Faster, he could get you a quote for a rebuild. If you have the manual and don't mind getting oily you could freshen it up yourself

[Clarkie]

Was the motor warm or cold when you did the compression test? It should be warm and it makes a pretty big difference

Also, balance the carbs :wink:

[James87]

Clarkie, I had warmed the engine to around 160 - 170 degrees when the test was done. Ya, I have instructions to put together a cheap carb balancer. I guess I'll putting those to use lol.

marty, Thats still a nice machine. Ill be calling Bart in the morning for a quote. I could do it myself, but all my benches are riddled with FZ 750 parts. The fun never ends. :lol:

[Clarkie]

Do a leakdown test and it will tell you if it is valves or rings, my race bikes were always 240-260 psi but I ran higher compression than most could get away 8)

[Fastt Racing]

If the bike has been sitting a while (sticky/glazed rings), and you cranked it with the throttle plates closed, you would get numbers like those anyway. A general rule of thumb is the cylinders should all be within 10%. It takes a bit more to condem a specific cylinder as having a serious sealing problem. You may want to get things squared away with basic engine management fuel/air to see how well it comes around. You really can't use compression tests as accurate data, they leave way to many valuable pieces of information out. Absolute barometric pressure in Denver was 24.45"Hg a few days ago. Compare that to 29.93"Hg at sea level and you are already at 80% of the specification in your manual just for alltitude compensation <124-170psi>. Good luck!

[James87]

Fastt Racing, Thanks for that very informative post! I had no idea altitude had adversely effected the compression test. I suppose it does make sense when you think about it though.

I know the bike has the ability run nicely so I will focus my attention on the normal maintenance stuff and also go through the carbs and fuel system to get everything in good working order.

Thanks again everyone!