GK73a SP will not rev out!
Forum rules
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
GK73a SP will not rev out!
Struggling to fix this. It get's to 12000 and then struglles to rev any more, could be electrical??? Just been on pdq's dyno
It should make low 60's not 50 odd.
I've changed coils, put a known good cdi, the fuellings about correct. Not sure if the engine has ever been fully apart. It has an aftermarket 4-1 with a yoshi can.
All that's left in my head is
- cam timing
- ignition pickup
Any ideas?
Cheers .
It should make low 60's not 50 odd.
I've changed coils, put a known good cdi, the fuellings about correct. Not sure if the engine has ever been fully apart. It has an aftermarket 4-1 with a yoshi can.
All that's left in my head is
- cam timing
- ignition pickup
Any ideas?
Cheers .
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
Re: GK73a SP will not rev out!
I think I may have found something: the rotor tips look like they've machined themselves off a bit?! now too much clearance to the pickup?
The cam timing is spot on, just checked that.
- Variablevalves suck
- Site Supporter
- Reactions:
- Posts: 2608
- Joined: Sat Jan 24, 2009 10:52 am
- Bike owned: GSXR Carb o'ring kits supplied
- Location: Stoke-on-trent
Re: GK73a SP will not rev out!
They usually look pretty tatty, definitely not a precision machined part and no clearance given for the pick-up.
I'm no expert regarding dyno graphs but surely it should (if correct) run at around 12/13, the sudden dip at high revs looks all wrong! I don't know which way it is, think lower is rich, but it would kill the motor revs.
What did the dyno guy recon?
I'm no expert regarding dyno graphs but surely it should (if correct) run at around 12/13, the sudden dip at high revs looks all wrong! I don't know which way it is, think lower is rich, but it would kill the motor revs.
What did the dyno guy recon?
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
Re: GK73a SP will not rev out!
PDQ recommended to check the cam timing- which turned out to be spot on. Or they said the exhaust might be restricted, but it hits such a wall at 12K that I think the exhaust is not really the problem. I have a gk76a 4 into 1 Yoshi system.
I've ordered a new rotor so hopefully will fix the issue. As said I've tried 2 ecu's, and 1 without the restrictor green yellow wire. and they both run the same!
I've worked on loads of bikes but this is really a head scratcher!
trying to get hold of a 35 x 1.0mm puller. They are thin on the ground.
I do know the bike had a fast lowside lh crash at some point, so may have broken the lh casing and damaged the rotor.
I've ordered a new rotor so hopefully will fix the issue. As said I've tried 2 ecu's, and 1 without the restrictor green yellow wire. and they both run the same!
I've worked on loads of bikes but this is really a head scratcher!
trying to get hold of a 35 x 1.0mm puller. They are thin on the ground.
I do know the bike had a fast lowside lh crash at some point, so may have broken the lh casing and damaged the rotor.
Last edited by moforockband on Sat Oct 17, 2015 11:28 pm, edited 1 time in total.
- Variablevalves suck
- Site Supporter
- Reactions:
- Posts: 2608
- Joined: Sat Jan 24, 2009 10:52 am
- Bike owned: GSXR Carb o'ring kits supplied
- Location: Stoke-on-trent
Re: GK73a SP will not rev out!
Ive seen the puller for £12 on ebay listed as a Kawasaki item.
Maybe some on here know a little about dyno graphs but surely the af shouldn't drop off like that.
Maybe some on here know a little about dyno graphs but surely the af shouldn't drop off like that.
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
Re: GK73a SP will not rev out!
Which kwak puller chris?Variablevalves suck wrote:Ive seen the puller for £12 on ebay listed as a Kawasaki item.
Maybe some on here know a little about dyno graphs but surely the af shouldn't drop off like that.
- Variablevalves suck
- Site Supporter
- Reactions:
- Posts: 2608
- Joined: Sat Jan 24, 2009 10:52 am
- Bike owned: GSXR Carb o'ring kits supplied
- Location: Stoke-on-trent
Re: GK73a SP will not rev out!
Hi mate, sure its 35x1.5
In the workshop manual ive scribbled Suz- 09930-34960 Yam- ym-01404. Kaw 57001-1223
These are all same so an equivalent to any of these, the one I got was about £12 or something.
In the workshop manual ive scribbled Suz- 09930-34960 Yam- ym-01404. Kaw 57001-1223
These are all same so an equivalent to any of these, the one I got was about £12 or something.
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
Re: GK73a SP will not rev out!
Yep you were right, it is 1.5mm pitch. Will order one up and report back if misfire vanishes
-
- Settled in member
- Reactions:
- Posts: 124
- Joined: Mon Sep 16, 2013 4:12 pm
- Bike owned: GK76a GSXR400R & TZR250RS
- Location: Fife, Scotland
Re: GK73a SP will not rev out!
I'm with you, VVS. From 11,500 rpm upwards the fuel/air ratio goes rich. (Too much fuel).Variablevalves suck wrote:...I'm no expert regarding dyno graphs but surely it should (if correct) run at around 12/13 (to 1 air/fuel ratio). The sudden dip at high revs looks all wrong! I don't know which way it is, think lower is rich, but it would kill the motor revs. What did the dyno guy recon?
I reckon smaller main jets are needed. It's also rich at 2,500 - 3,000 rpm. Between 4,500 & 7,000 it's a touch lean.
-
- Familiar Member
- Reactions:
- Posts: 388
- Joined: Wed Jun 03, 2015 9:41 am
- Bike owned: GK73a SP CRM250 mk3
Re: GK73a SP will not rev out!
Replaced ignition trigger with no improvement Was a bitch to put back on, as I didn'[t realise you have to clean ALL the oil off the crank taper before fitting it as otherwise it slides on too far and the starter clutch ends up binding. Sigh!
Looks like compression issue may be on the cards, I'll start another topic LOL
Looks like compression issue may be on the cards, I'll start another topic LOL