Lacking Power!

[ryan600]

Hey
i got my d600 from some guy who had restored the bike from a tatty state. Everything appears to be ok except the top end power. Flat out, no wind and going down a slight hill i managed to touch 90 mph but back on the straight it lost power to about 80-85mph. There doesnt seem to be any excess engine noises or smoke however it does sometimes feel a bit spluttery when trying to accelerate hard.

Can anyone think of any reasons for this? My only thought is that a restrictor kit has been left on!! if so where is it and how would i take it off?

cheers for any help
ryan

[chunk166]

you could try the air filter, it may be a little clogged up.only a suggestion as i'm not as technically minded as some of the others

ray

[Fiasco]

Apr 22, 2008 21:15:56 GMT @ryan600 said:

My only thought is that a restrictor kit has been left on!! if so where is it and how would i take it off?

That was my first thought too, I think it is in the carbs somewhere, hopefully someone will be along to be a bit clearer !

Good Luck

Dave ;D

[steved]

My d6 restricted does about 85/90 on the flat, although my kit is from the earlier xj, which i think has the bigger carbs?

[Padster]

The first port of call is to see if you have restrictors fitted. The in carb ones are plastic inserts so if you take the top off one carb it will be obvious if they are fitted. The other type of restrictors are fitted between the carbs and the barrells and are just discs with a smaller hole to restrict the air flow.
If neither of these are present then a methodical approach. Check the air filter as suggested. Then check the connections around the coils and spark plugs. Have a look at the spark plugs, their colour will indicate how the fuelling is working. It is worth balancing the carbs as a spluttery effect can be an indication of them being out of balance and working against each other. Make sure there is a fuel filter fitted so no crud from the tank can get to block the jets.
A poor electrical connection in the ignition circuit can cause the same symptoms so check the wiring from the ignition, on my D6, D9 and XJ900F I have had an ignition wire connection corrode and cause a breakdown. The first symptoms being a hesitancy and spluttering.
Do these one at a time and see if it makes a difference. If you do them all at once it would mean doing everything again should the problem recur.

Good luck

Paddy

[General Gman]

Wot Paddy said.....
And if all that fails then you need to look at the fuelling, so time to strip the carbs, check emulsion tubes for wear, main jets, float heights etc.

[darren]

what they said, but by the sounds of it, it seems restricted if its losing its edge at that speed, if not it could possibly be coils breaking down or as said ignition side related

[dubster]

Thanks for all this info guys, my D600 is exactly the same, it starts and rides lovely but it runs out of steam at around 80 and will eventully creep up to about 85!
I'm going to service it this weekend, but I'll definately be checking for a restrictor kit.
I'll let you know what I find Ryan...

cheers

Rich

[amorti]

I'm generally disappointed with the D6's speed, and that's given that mine reports back about 120 before it stops going up. Not bad for what it is? but then, my 45-50bhp 400 beat that, and it had no fairing, and surely wasn't that much lighter with a steel frame too, and a radiator and water to lug about. Also, the 400 didn't wobble half as much at or around those speeds.

So, good thing I'm getting too sensible to go that fast, then.

*looks forward to receiving his top box rack in the post*

[ryan600]

Cheers everyone i'll try to have a look next to see what i can find hopefully it is as simple as a forgotton restrictor kit!
good luc with yours as well Rich

[cam7777]

My D900 lacks power ......mind you, previous bike was a Bandit 12

[pinkunicorn]

Apr 23, 2008 6:41:30 GMT Padster said:

The first port of call is to see if you have restrictors fitted. The in carb ones are plastic inserts so if you take the top off one carb it will be obvious if they are fitted. The other type of restrictors are fitted between the carbs and the barrells and are just discs with a smaller hole to restrict the air flow.
If neither of these are present then a methodical approach. Check the air filter as suggested. Then check the connections around the coils and spark plugs. Have a look at the spark plugs, their colour will indicate how the fuelling is working. It is worth balancing the carbs as a spluttery effect can be an indication of them being out of balance and working against each other. Make sure there is a fuel filter fitted so no crud from the tank can get to block the jets.
A poor electrical connection in the ignition circuit can cause the same symptoms so check the wiring from the ignition, on my D6, D9 and XJ900F I have had an ignition wire connection corrode and cause a breakdown. The first symptoms being a hesitancy and spluttering.
Do these one at a time and see if it makes a difference. If you do them all at once it would mean doing everything again should the problem recur.

Good luck

Paddy

Oooooh now I know where the restrictors are fitted I might remove it next subject for the mintenance course - How to remove ur restrictor kit! ;D

[neilmud Lord Protector]

My Fazer lacks power oops heated grip has slipped round again can only get 1/4 throttle cables got tight thats why I had to get rid of the D900

;D

Neil

[dubster]

Hello all,

Finally got chance to work on the bike over the weekend, the good new is that I have found the problem regarding the lack of power, the bad news is that this has now highlighted another issue

I took the tank off and removed the airbox, and found that there was no air-filter at all! Needless to say that one was bought and installed when I put all back together. However I started to remove the inlet manifolds to spy this:



A clearer view:



Well that answered the power issue problem, it was definately restricted!

10 minutes later, and I have all these out:



Whilst I was at it I also changed the oil and filter. I put everything back together and went on a test flight, and now there is loads more power, the bike acceleated really quickly to 75 but then the clutch started slipping... bum!

So I don't know if the clutch is simply borked and the extra power now makes it slip, or wether there is another problem.

I really wish I had tested the bike BEFORE changing the oil, in case the clutch doesn't like the new oil? It should be okay though as I used Yamaha's own semi-synth.

I have this horrible feeling that I've bought a bloomin' project bike again

[amorti]

Mine slipped once at .. well, a bit more than 75. Opened it up and changed the clutch plates, job done. Check there is enough freeplay at the clutch lever, and the cable is moving freely before opening the engine.

[dubster]

I really don't want to spend much more money on the bike at the moment, so I will check that the cable is moving freely and check the clutch adjustment. If I end up replacing the clutch do I simply need to buy the plates, or should I be looking at replacing springs etc?

Also, I have never restricted a bike before, would it have been likely that the carbs would have been rejetted to account for the inlet manifold restrictor plates?

thanks to everyone,

Rich

PS. Ryan, have you had any luck with your investigation?

[amorti]

No. they don't touch the jets all it does is tricks the carbs into only having a certain amount of vacuum through. It's as if from opening your throttle 40% (guess) through to 100% makes zero difference.

If you do it, you will need a gasket and plates. You "should" do springs. I didn't just because fowlers sent me the wrong parts, but it's less than a tenner morefor a set of springs so while you're there...

I would say the clutch will give you plenty of warning before it dies, but it will lose the last bit of wear much quicker, and then that will be because the last bit of clutch has worn apart, and then you will have to do the oil too.

Aren't project bikes great?

[General Gman]

Apr 23, 2008 15:23:24 GMT amorti said:

I'm generally disappointed with the D6's speed, and that's given that mine reports back about 120 before it stops going up. Not bad for what it is? but then, my 45-50bhp 400 beat that, and it had no fairing, and surely wasn't that much lighter with a steel frame too, and a radiator and water to lug about. Also, the 400 didn't wobble half as much at or around those speeds.

So, good thing I'm getting too sensible to go that fast, then.

*looks forward to receiving his top box rack in the post*

The CB-1 has got to be at least 15KG lighter.... and the gearing is totally different.

[rossm]

Apr 23, 2008 16:31:09 GMT @cam7777 said:

My D900 lacks power ......mind you, previous bike was a Bandit 12

With you on that, my last bike was a R1, divvy 6 feels a little bit breathless in comparison

[darren]

probably a worn clutch at that age, mind you, saying that, I changed my clutch and found out there was bugga all wrong wiv it, it turned out to be the cluch cable was that clogged up with carp it took its time to dis-engage, so renewed the cable and all was fine again, i could have saved 35 quid on a clutch though

[dubster]

Cheers everyone, I'll certainly check the cable first, I'm just a little concerned about the oil, as previously the was no hint of clutch slip at all, but now I've changed the oil it's really bad, mind you it now has nearly 30bhp extra...

[darren]

Apr 28, 2008 16:12:32 GMT dubster said:

Cheers everyone, I'll certainly check the cable first, I'm just a little concerned about the oil, as previously the was no hint of clutch slip at all, but now I've changed the oil it's really bad, mind you it now has nearly 30bhp extra...

what oil did you use? hope it wasnt high grade car oil or fully synth, and mineral is normally not that good either, I always use semi synth, the stuff I use is GM semi synth in a grey/blueish container (normally for cars)but does not have any of the additives that cause clutch slip, changing the oil then getting clutch slip is defo a sign of wrong oil, but let it run for a while as its already soaked into the plates anyway and it could be just the residue oil from the old that has mixed if it was a different grade or to begin with, if it keeps happening after a few times the change the oil before you burn ya plates out

[dubster]

Apr 28, 2008 16:25:59 GMT darren said:

Apr 28, 2008 16:12:32 GMT dubster said:

Cheers everyone, I'll certainly check the cable first, I'm just a little concerned about the oil, as previously the was no hint of clutch slip at all, but now I've changed the oil it's really bad, mind you it now has nearly 30bhp extra...

what oil did you use? hope it wasnt high grade car oil or fully synth, and mineral is normally not that good either, I always use semi synth, the stuff I use is GM semi synth in a grey/blueish container (normally for cars)but does not have any of the additives that cause clutch slip, changing the oil then getting clutch slip is defo a sign of wrong oil, but let it run for a while as its already soaked into the plates anyway and it could be just the residue oil from the old that has mixed if it was a different grade or to begin with, if it keeps happening after a few times the change the oil before you burn ya plates out

I used genuine Yamaha semi-synthetic oil, yes I know it's expensive, but I was there at the dealer getting an air-filter and I needed to get home to put the bike back together! Saying that, the oil should be perfect for the bike, so I can only assume that the clutch was virtually shot but the being restricted the bike didn't play up, obviously now I have more power it is showing up as buggered

To cap it all, I've just been out again and now one of the exhausts is blowing on the joint into the cylinder... I wish I never bothered with the bloody thing!

[darren]

if ya skint, i I still have the plates out of mine, as there was nowt wrong with it, you can have them if push comes to shuv in the finance department

[ryan600]

hey i took the carbs off and searched for the restrictor plates but couldn't find anything and the air filter is good to so im kinda back to square one i'll be checking the sparks soon but where is the coil?
cheers

[taint]

Ryan, I don't know if you've caught it wrong or if I've read your reply wrong (apologies either way )

The restrictor plates are lower than the carbs, you need to actually need to remove the inlet manifolds (the pipes below the carbs). If you look at Dubster's photos you can see the plates.

For the coils, while you have the tank removed, follow the spark plug leads to the coils; they're connected to the frame just behind the steering; a pair of black cylinders with square metal posts front and back.

I hope that helps

T.

[ryan600]

Hey Taint
i took the inlet manifolds off but nothing there and everything looks in great nic and clean, tonight i'll have a look at the coil and the spark plugs but with the coils i'm not to sure what i'm actually looking for other than obvious breaks?
cheers

[dubster]

Apr 28, 2008 22:08:39 GMT darren said:

if ya skint, i I still have the plates out of mine, as there was nowt wrong with it, you can have them if push comes to shuv in the finance department

That is very kind of you, but I going to hold off with replacing the clutch at the moment, I've adjusted the cable, and now it doesn't slip until the revs hit 8K, so I can live with it at the moment

Biggest issue though is the blowing exhaust, which turned out to be corrosion around the flange that bolts to the engine, unfortunately it snaped completely yesterday, leaving me with a 30 mile (very loud) ride home, so now I need to invest in a set of downpipes.

I've got the feeling that I've bought a dog, and the barking is keeping me awake at night...

[taint]

Hi Dubster,

I think it goes with the territory; the Diversion was designed as a cheap commuter/first time bike. It's not a particularly powerful/flash bike and therefore doesn't get treated with a lot of respect.

As such, most of the examples I've seen on the road are in quite a poor condition. Extended service intervals, infrequent cleaning/maintenance, stored outside, etc, etc.

On my D6 I've had to replace the front and rear suspension, I've gone through 3 back brake calipers and a huge amount of overhauling, cleaning, painting and repair work. New seals, calliper pistons, oil, filters, plugs, tyres, bolts and soon to be chains and sprockets. I've only owned my D6 for just over a year and I'm finally getting to the point where I'm happy with the condition; but even if I hadn't done all that work, it would still have been road worthy.

What the D6 has in it's favour is the ease of service, cheap parts, a fantastic community, and an engine that just keeps on going; even with fairly minimal maintenance and huge mileage.

I'm only a beginner amateur mechanic and most of what I've done to my bike I couldn't have done on a more complicated bike. To start with the parts would have been more expensive. The community have also been absolutely invaluable. There's a wealth of knowledge here and a lot of friendly helpful people who can help you get through.

Hopefully, someone out there can help.

(sorry to preach )

T.

[CD]

Go for those free clutch plates changing them is an easy job and if you leave the bike on side stand you dont even need to drop the oil.