Ray Stringer’s live advice clinic

Published: 01 August 2001

MCN:- I own a 2000 CBR600FY, I’m 6' 1'' tall and weigh 13 stone. I find that to prevent the bike from wallowing in bends I have to increase the rebound damping so much it becomes uncomfortable the rest of the time. Would different springs to suit my weight help?

RayStringer:- Yes. Yeah, if you went to a proper weighted spring but you'd probably want more compression damping on there more than just rebound damping

MCN:- I have a Thundercat that is ridden mainly two-up, our combined weight is around 22 stones, how would you suggest the suspension is set up?

RayStringer:- The best thing to do is to adjust the pre-load on the springs, to add more preload and about 3 or 4 clicks of compression and maybe 2 clicks of rebound to make it a bit stiffer a standard bike has a spring with a lot of pre-load on it to begin with and if you put just a bit more pre-load on, it tops out a bit so move the pre-load up, and then adjust the rebound and compression Or, if you are doing a lot of two up riding, then go for a heavier spring, which will cost around 50 quid. Or, just leave the pillion at home!

MCN:- I have a YZF750 with 9000 miles, when I first start it after it's been lying in the garage for say a month, the engine smokes until warmed up, after that it's fine. A friend said that this was due to the barrels being glassed. My question is if I added Redex either direct into the barrels or to the petrol, do you think this would clear it up?

RayStringer:- No. I don't think it would do. It depends what colour the smoke is really to tell what's wrong with it and if it's been standing a while it's probably the carbon etc that's built up when it's stood and it tends to come off the exhausts etc quite easily when it's started up. If it's a more white/grey coloured smoke as opposed to black that would indicate more of a problem

MCN:- I have a 1999 Kawasaki ZX9RC2, which Has had a fork conversion done by Maxton and new Maxton rear shock. The suspension was set up by Maxton and has made a vast improvement to the handling of the bike. But I do have a problem with the front forks chattering when I braking hard. Can you give me some advice on the cause as I don't want to start fiddling with the suspension settings if it is head race bearing that are to are to blame!

RayStringer:- If it's chattering under brakes, that would normally mean it's bottoming out. You're looking for between 18 and 24 mm static sag. When the bike is sitting there and you pull it up it's the gap between the fork leg and the fork stanchion and it should be between 18 and 24mm. If this is fine, you may need to go to a heavier spring. Springs go from .8 to 1 kilo and depending on the riders’ weight, you might need a heavier spring. I’d say try another couple of clicks compression once you've adjusted the static sag to between 18 and 24. Or, slow down a bit...certainly until it's sorted

MCN:- I messed with the front and rear suspensions on my Thunderace as I was loosing the back end on tight corners and powering out of bends. The bike seems to wallow. After my adjustments the rear end skips out and looses traction - I have probably firmed it up to much?

RayStringer:- Well yes. The wallowing would have meant it was too soft so it would seem as if you've gone too far and obviously tyre pressure can affect it was well if you're running a really high tyre pressure then that will also affect it. Normally for most tyres you want around 30-32 psi in the rear for fast riding most manufacturers recommend around 34-36 which is a little too high for fast riding. Or just get some stickier tyres

MCN:- Hi Ray, can you please tell me if it is ok to fit my end can from my Kawasaki ZX6-R G1 model on to my ZX6R J1 model ,the fittings seem to be the same

RayStringer:- Yep, should be completely ok

MCN:- I have the following problem, which I am sure Ray will be able to resolve. I have a 1989 ZX10, which I recently bought. The problem is that the temperature gauge indicates that the engine is running cold the whole time. I have checked the gauge itself by shorting it and it deflects correctly. I have also checked the resistance of the sensor which ranges from several ohms at room temperature to around 37 ohms close to boiling point (the manual suggests it should be 27 ohms at 100 deg C). The only thing I haven't checked is the thermostat - and thoughts?

RayStringer:- Yeah check the thermostat. It may be just open all the while and just not getting any heat in it and this time of year it should be getting hot really

MCN:- I was riding the other day and noticed that the bike was having a hard time staying in the corners when turning. When I did my pre check of the bike next weekend, I checked the front tyre pressures, and it was 38psi, normally it is 33psi. Could this have caused the bike to run wide on corners?

RayStringer:- I suppose the answer is yes, it could be, but it's a difficult one to answer tyre pressures do play a big part in turning and if everything else is the same it could well be.

MCN:- Hi Ray. I have a Laverda 668 Ghost Strike. As the manual recommends a fully synthetic oil, I’ve always used Mobil 4T Racing. But I find that the clutch has now become sticky, so much so that when left overnight, the engine stopped, in gear with the clutch lever in, the bike will drag the rear wheel when pushed. Starting the engine in neutral, free wheeling down a hill, selecting 2nd and applying the clutch and brakes at the same time, is about the kindest way I’ve found to free it, although not always practical. Also my oil combustion has been pretty high using about 750ml per 1000km. Now the bike has only 22000km on it. Can you recommend an oil that may overcome these problems?

RayStringer:- Mobil is a very, very thin oil. I'd recommend Rock Oil they do it in different grades they'd recommend which grade to run in your manual and Rock is good, being a dedicated bike oil. You may need to take your clutch out and clean the pads off as it may well now be contaminated by the oil so it'll need to be cleaned.

MCN:- I just have a couple of question for Mr Stringer:Best way to get approximately between 125bhp to 130bhp at the back wheel of a ZX7R(P5) while still being reliable. I was thinking about a big bore kit (780cc, cheap at abount£1000); How can I loose about 20Kg to 25Kg of same bike? I love the bike and therefore not looking for another.

RayStringer:- We stroke the ZXR750. Which with the right exhaust will give around 125bhp and with the right cam it will do 135bhp. We do a ride in, ride out price with the cam for £1700...or without £1500. I’m not particularly happy with boring stuff myself To lose weight the first thing is to get a new system. OE systems are very heavy. Carbon air scoops up front would be handy...for about £120-£130 and you'd lose a lot of weight and those two together would get you close to that sort of weight. The only other thing is to get the fabricated ZXR750 swinging arm from a "K" model, and that would also save you some weight. Swinging arms are about 150-200 pounds, from a breakers

MCN:- Ray, I have a CBR600F S and find the front end very vague. I am a bit of a fat boy at 16.5' kitted out. I have adjusted the pre-load on the bike, but still find the front end often feels as though it might tuck. Any thoughts? It also has D207 tyres.

RayStringer:- Basically a lot of the problem will be down to weight, so i would recommend heavier springs to start with and also heavier oil because the bike is bottoming out due to rider weight, it's bottoming even more in the corners the standard springs are about .8 so go to about a .95 spring the tyres are ok though.

MCN:- Hi Ray, I’ve just fitted a scorpion can to my 99 R1, do i need to fit an exhaust gasket, there wasn’t one with the kit......thanks

RayStringer:- Err, yes you should do. There should be one on the standard one that should fit. The standard one should do the job

MCN:- Ray, what is the best suspension set-up for a 18-19 stone 5'9" rider on a W plate vfr800i bt020 rear bt57 front. I use the bike for more sports than touring?

RayStringer:- You'll really need heavier springs and oil again, like the previous questions. The VFR is a bit wallowy even with a lighter rider. Start with more pre-load compression and rebound and that will help but it'll probably be better in the long run to just use heavier springs as a starting point

MCN:- Hello, I have a CBR 600FX, I have noticed that under heavy breaking I am getting a juddering from the front of the bike (chatter), what can I do with the suspension to cure this problem as I am loosing feel when it is chattering?

RayStringer:- Stop braking so hard for a start or...again...more pre-load on the spring and a few more clicks compression damping. With standard road springs they can be too low they tend to start at .6 of a kilo...race settings start at .8 so that would helps you out loads if you are riding the bike hard

MCN:- Hi Ray. Can you tell me the things to look for which cause bad vibration on my CBR600FN? I can only travel 20 miles and my fingers start to go numb. I have had the carbs balanced and also looked at the engine mounts to see if the are set to the right torque. These seem ok. I have also noticed the top rear engine mount is adjustable? Why is this?

RayStringer:- The engine mount is adjustable to get the engine in and out…makes it easier. A lot of the vibration could be due to a bad crank coming out of the factory The only way is either sell the bike or get the crank balanced. Unless you have taken the balance bobbins off the end of the bars and replaced them with nylon ones...that can cause a lot of vibrations through the bars

MCN:- Ray ,I have a 2001 R6 which needs tyres and have see to have hit a mine field of conflicting advice, should I go for Supersport tyres like' Supercorsa' or sport tyres for fast road use and occasional track days

RayStringer:- It's really your choice. If you're using it on track days then it will need more sporting tyres like Supercorsas or Evo's they'll be better for track days but obviously will last less time. It all depends on what you are after if tyre wear is important stay with your normal Pirelli Dragons etc. I would recommend the Pirelli Dragons as a could all round tyre for the R6 anyway.

MCN:- Hello Ray, what tyre would best suit my GSXR750k1 and would the psi be the same as stated on the swing-arm i.e. 36 front & 36 back many thanks.

RayStringer:- Best tyre? I’d have to recommend the Pirelli Evo Corsas, or Metzeler MEz Evo 2 would work really well. But you'd want a little less pressure to feel more through the tyre around 32psi. 36 psi is better for touring and longer tyre life but 32 front and rear will let you feel what is happening a bit more.

MCN:- Ray, you have previously recommended that a cure for a spongy brake is to tie the brake lever back to the bar over night. I have tried this and initially the brake is very firm, but over a few hours it gets more spongy, any ideas why?

RayStringer:- Getting air in the system. It might just need bleeding properly. The seals might need replacing as well

MCN:- Do Supersport tyres warm up enough on the road?

RayStringer:- Yes they do...yep

MCN:- Hi Ray, I have a 1999 RS 250 which in it's short life of 4000 miles has seized the same cylinder twice and destroyed the crank on the same side once, Do I need an expert like yourself to tell me to get rid of her or should I persevere ? Three workshops have looked at the bike during my ownership and none of them can set the furling up right and all of them are baffled by the constant problem and then blame the last garage for a bad repair job. Is this norm ?

RayStringer:- No, it's not the norm no. More likely it's just running lean on one of the cylinders two strokes are a bit funny if they are running lean and are more likely to seize up so it might just need running on a dyno especially if it has an aftermarket exhaust or air filter

MCN:- As I’m relatively new to biking having bought a Honda CBR600FX in May, I know absolutely nothing mechanical and apologise if this is a stupid question. I have heard that all gear pedals are set for the average person in production, however, it seems that I`m not average as I find I have to put in a lot of effort into changing gear. What I really want is it to be just a flick of the pedal. I think I need to lower the pedal so my foot is pointing nearer the floor, so is this a simple job I could do at home, bearing in mind I`ve never tried this kind of thing before?

RayStringer:- It is a simple job, as it's just a couple of simple adjustments. I think there should be an adjusting/linkage rod and there should be some locking nuts on it so slacken them up and adjust it how you want and then just tighten the lock nuts up again

MCN:- I have just bought a 1999 GSX-R and a booked a trackday at Brands. What settings would you recommend, when I am 12 stone and 5'7. I have just put some Dunlop Sportmax tyres on the bike.

RayStringer:- Better tyres to start with. Sportmax are a sports tyre, more than a track tyre really. If you're going on the track it's much smoother than on the road, so stiffen up the pre-load a bit and same with the compression. Not too much rebound damping on just a couple of clicks on pre-load and compression.

MCN:- One of the top engine mount bolts on my GSX-R is seized. I don't want to round the Allen head, so would you recommend heating the bolt to free it up a bit

RayStringer:- That'll help out yeah, or put the Allen key in and just give it a whack with a hammer to shock it loose along with a bit of penetrating oil. Don't get it too hot obviously!

MCN:- Ray, I have an R7 which isn't making enough power for me anymore, if anything I think it has lost power since it was originally unrestricted! I'm keen to get more power from the bike but don't wish to go to the expense of an S kit or sticking an R1 motor in the bike! How can I get more performance without losing reliability??

RayStringer:- Well you can't really get more power without less reliability. You can get around 130bhp from full race kits, but it probably just feels slower, because you've got used to it. There are conversions for full kits from us for under 2 grand, as opposed to the Yamaha version for 5 grand

MCN:- Dear Ray, I’ve just purchased a K plate Yamaha Diversion 600 with 21000 miles which has a wee problem when it's hot it idles fast. After revving it the revs drop to around 3000rpm for a wee while then drop to 2000rpm for a while, then drops down to a normal tickover. A local mechanic thinks it needs a new set of carbs. It is my first bike, and don't have a lot of spare cash, so I would like to hear your opinion.

RayStringer:- It sounds more like it's running a bit too lean on the pilot screws, or pilot jets themselves. It's a simple job to do but if you go to a local garage or dyno. They'll be able to do it for you but you don't want a new set of carbs basically