03 450fse advice on upgrades to improve starting

[hillbilly]

Bought bike 1 year ago. Reluctant/slow turn over to start when bought but ran well after bump starting. Got it cheap because of this, still on tight budget though. Read up a lot on here and have done following:
Overhauled starter, full of dirt. New brushes, blocked hole at front
New battery, Yuasa
Re shim ex valves, (this increased decomp valve lift slightly)
New plug
Repair various wiring insulation splits.
Replace faulty fuel pump relay
Keep battery connected to Optimate charger all the time.
Discovered cold start button on back of throttle twist grip.
All this resulted in bike starting more reliably, best improvment was cold start button. Press it in, dont touch throttle and starts nearly first turn. Hot start not so good but several short stabs on starter usually does it.
Recently getting more difficult again, slower to turn over, pulling battery down due to having to try more attempts. Checked valve clearances, stripped starter both of which ok, pulled plug, sparks ok.
Starts ok now but only just,still spins slower than previously. Always wary when I go out that I could get stuck somewhere if I have stopped and need more than 3/4 attempts to start and run battery flat. Even fully charged at 13v turn over slow at best and 5/6 aattempts is all you get then wait for battery to charge again
Wanting to know what is the best answer to upgrading starter system to give more powerful and faster engine turn over as this seems to be the issue as bike runs well and fires up quickly if turning over fairly quick.
Read about fitting 04 cam for more decomp, different starter, different batteries etc. Had already had sprag clutch upgrade on starter when I got it.
What is the definitive way to get these things to spin up better and to get more than 4/5 attempts? Someone must have done it or do you just change bikes and give up as I 'm close to doing. Love riding it, but takes away the fun when all you think about is can't go far in case it won't start! Based in UK by the way. Love to hear there is a master solution.

[gasmonkey]

That model is getting long in the tooth now(old).Upgrade to an 06+to cure estart probs or a ringding 2stroke.
Been there done that.

[450GASGAS]

I read on here that changing the cam chain tensioner makers starting easier. Apparently the automatic chain tensioner is too tight and makes it hard too turn over. Do a search on here and you should find the details

[hillbilly]

Cheers lads, tried tensioner idea, backed off to release some tension, chain little slacker but still sluggish. Does start but wondering if it will let me down at random times spoils the riding. Thinking to go back to 2 stroke, this is first 4t and although good for some of the road work between trails here in UK not enjoying the added complications, costs and issues with 4 stroke. Fancy 300 GG, always had 250 but ridden 300 and nice. Not so revvy for road work either. On a tight budget so unfortunately 06 era bikes not an option. See if I can get rid of FSE first! Few boy racers round my way who may have it for summer posing round town. See how it goes

[flybars]

If U do a search on the manual cam chain tensioner, there is one to purchase for your bike. Not expensive. Also I have read a little about the new light weight Shorai battery which is supposed to have much more cranking power than lead acid batteries and much better than the turntech battery. Also it's supposed to outlast other batteries by quite a bit. Might be a good solution. They're spendy, but since they are said to last longer and crank better, might be worth it.

[hillbilly]

Perhaps I'll go for manual tensioner having read more. Surprised it could make that much difference. Will look into supplier in Uk first. Battery sounds worth a try too, can't find anything about it in Uk yet. Any more info on that appreciated. Is it US supply only do you think. Do you know any more about newer cam upgrade or different starters? Read a bit about both being done but unsure whether these mods give a real significant improvement especially for costs involved. Will spend a bit but only if I know it's definite fix.
Anyway, thanks for your input, much appreciated. Ii do like to ride it so would be sorry to let it go and 2 strokes more hassle out on trails with oil to worry about and buzzy one the road. think I'll give it this summer and see how much hassle I have and try and mod as and when I can afford it.
Cheers again

[Ivan Svea]

So, I have a '04 450 (starter in front of cyl) that ran great when I bought it, Aug 10, but started stalling at idle for no reason, and now is intermittent starting.

It doesn't appear that there is one fix for these bike's problems, but many little things that you check over and over when it craps out the next time. So, I'm thinking that it's worth buying one of the ECU monitor systems to be able to diagnose where to look for a problem. At $229.00 USD, it could save time and many needless part purchases. Plus I'm as good as my local GG mechanic and the labor is a lot cheaper.

The reccomended repair guy broke one of the ground leads, put the bike back together, and told me that there was little he could do without the analyzer. At least he didn't charge me.

Now, I'll start with a new battery (replaced 4 years ago) and a ECU tester and see where the codes lead me...

I'll gladly take suggestions and guidance, please advise.