Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: Danxup on May 02, 2018, 08:44:10 PM

Title: Srx hard to start when warm
Post by: Danxup on May 02, 2018, 08:44:10 PM
Ey up..  ive recently purchased a srx600. it starts prfectly from cold usually second kick.. runs sweet.  rides sweet...
But ... she is an absolute pig to start when hot.... could anyone help please.. many thanks
Dan..
Title: Re: Srx hard to start when warm
Post by: themoudie on May 03, 2018, 12:04:42 AM
Aye Dan,

Welcome to the forum, others maybe along to chip in their pennies worth; here's mine for a start.

I have a 1986 SRX600 'Sally', don't ask  ;D  and starting was a bit hit and miss, cold or hot. I suspect that the hot starting problem is due to the fuel in the carbs evaporating due to the heat after a good run. Or else the coil insulation may not be liking the heat and breaking down, but I think that this is unlikely. Sally sometimes 'dies' after a good long run, with fuel starvation, inspite of the tank breather being clear, the cure is to switch to 'PRIME' on the fuel tap and then revert to the vacuum 'ON' position. If your vacuum hose is old and perished, its replacement, maybe the easy fix.  :-X  Also, try priming the cylinder with one or two gentle kicks, with the ignition 'OFF', this helps ensure any loss to evaporation is avoided. But beware, you may get a cracker of a backfire, when you turn the ignition back 'ON' and give the motor a good swing!  ;)

I would suggest a check of the air cleaner and fit a new one, if necessary. I'll leave the choice of OEM or equivilent to you. Maybe fit a K&N, as I did 12 years ago, although the current price is horrendous, they are fit and 'forget' (almost), and being washable last the life of the bike.

Check your spark plug and renew if at all in doubt, I use an NGK Iridium plug (DPR8EIX-9 Iridium), again they are no cheap, but fitting one made Sally easier to start and smooth running.

Check that your choke plunger is not siezed in its bore and that the whole mechanism is free to move, including the cable. They often come out looking like a good Thai red curry sauce if the water has got in and started to corrode things. refurbishment parts kits are obtainable from NRP (NRP_link (http://www.nrp-carbs.co.uk/index.htm)) or Wemoto (Wemoto_link (http://www.wemoto.com/bikes/)).

Check that the fuel filters in the bottom of the petrol tank, carburettor and any supplementary ones fitted in the fuel lines are clean.

Check your valve clearances, they may be "tight" when the motor is hot, adjust if necessary.

And check that coil, just in case.

The other thing to check is the generator as this supplies power to the ignition, regardless of the condition of the battery and if the shellac is startinmg to break up on the coil windings with heat, this maybe another problem. But, as I have said before, I would check the fuel side of things first. Sally is now up to 120,000Kms and seems ...... :-X  ;)

If you need a workshop manual, I can supply a reasonable pdf copy FOC. Private Message me with your email address, via the forum and I'll send one across. The PM link is on the left side of the message window, below my avatar.

I hope this helps.

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Danxup on May 03, 2018, 04:12:45 AM
Bye eck bill.. thanks for all that info... very much appreciated.
Ill let you know how i get on.. mine is also a 1986 its in decent order other than this problem.. thanks again.. ill message you for the manual too thats ace!!
Title: Re: Srx hard to start when warm
Post by: Steve Lake on May 03, 2018, 07:26:59 AM
Hi Dan, welcome to 'the madhouse'....
I have owned 7 srx6's.... currently 3 in the stable, & only one 'on the road' at present.
only ever had one of them that had your problem (though it is a well recorded issue on these bikes)
Bill has pretty much covered all the angles, I'd certainly put them in the order of 1) Fuel. 2) coil. 3) generator breakdown.
you really need to strip out the fuel system, from tank to inlet manifold... clean and/or replace anything that looks 'iffy', and if possible get an air line onto the carbs. the fuel tap can be an issue, but as Bill says running it on 'prime' in effect bypasses the vacuum valve.
(you can get a service kit for these taps, but beware... my Son got a kit for his SRX, but it appears it's already failed and is probably cheap crap not up to dealing with current fuel technology).
Coils can be obtained, but a bit pricey.... I have a working spare which you can borrow as a diagnostic tool should you wish.
Generator... only way I've ever tested this is just to take the plug out and kick the motor over and look for a spark ( this is huge fun to do when the engine is stinking hot after a good run :-) ), I do have an oscilloscope, which can show the size & duration of the power pulse from the generator to the coil... but not the power of the pulse.
not sure where you are Dan.... I'm near Norwich... if you're within marching distance bring the beastie round here ....
good luck
Steve (L) (we have a few Steve's lurking in here  :D )
Title: Re: Srx hard to start when warm
Post by: Danxup on May 03, 2018, 07:45:23 AM
Now then steve.. im up in west yorkshire near wakefield im affraid .. thanks for the tips ill start with the fuel then and work my way round.  Much appreciated.. a trip to Norwich might be in order if i get stuck 🤐 i have a 87 400 that has the opposite problem takes abit to start but once warm fires firts time evry time.. are the coils the same do you know ? I could swap some bits about .. cheers steve!
Title: Re: Srx hard to start when warm
Post by: themoudie on May 03, 2018, 09:43:13 AM
Aye Dan,

Manual on its way!

As for the 400 being a slouch to start when cold. Try the priming technique mentioned in my first post. Fuel tap to 'PRIME', full choke, 2 or 3 easy swings through the 4 stroke cycle from TDC, then switch the ignition 'ON', and with the piston just eased over TDC, give it a lusty swing. DO NOT OPEN THE THROTTLE! Once running, apply only a smidge of throttle and ease the choke to the halfway position (there is a positive stop on the lever) and warm the motor through. With Sally I usually get underway at the half choke stage and then use small throttle openings to warm the motor through, whilst going up through the gears. Knock the choke 'OFF' after a couple of miles and apply throttle!  ;)

Also, don't 'lug' the 600 in 5th gear, it is a known weak point and the torque will strip the teeth from the gears and or pit them severely.  :(  This results in a complete engine strip to replace the offending gears.  >:(  I would advise that you don't select 5th unless you are doing at least 50mph - 55mph, with 3,000rpm plus. I apologies if this is all familiar to you, but I thought that I should mention it, just in case. Both SteveL and I, along with others have had this problem to sort out.

My regards, Bill

Title: Re: Srx hard to start when warm
Post by: Steve Lake on May 03, 2018, 09:56:07 AM
Spot on Bill, as you know, #1 SRX6 is still in the waiting room, in the queue for a gearbox repair ... hopefully get it done before the anniversary of the 'crunch' which was August bank holiday ... on my way to Wimbotsham classic bike show.... difficult to apply my mind to it when #6 is looking so good and going so well  :D....
pip pip
Title: Re: Srx hard to start when warm
Post by: Danxup on May 03, 2018, 12:45:22 PM
Cheers for the advice on 5th gear.  The bloke i bought it of said it had had a full rebuild 2000 miles ago due to the 5th gear thing... ill bear it in mind when out scratching..
Ill let you all know how i get on . 😁⚡⚡
Title: Re: Srx hard to start when warm
Post by: themoudie on May 03, 2018, 08:28:58 PM
Aye Steve,

"Sally" all ship shape again after the collision, just waiting for the leg to be able to cope with turning her over!   ;)

"Gert" the SRX Mono is taking up the time, along with the Duke 450, and the weather hasn't exactly been conducive to getting my confidence back again.

Just make sure that tank and the carb haven't any rank fuel left in them, or else you may have another expensive job on top of the engine rebuild.  :(

Good health.

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Moto63 on May 04, 2018, 07:19:39 AM
[quote author=themoudie link=topic=9253.msg65488#msg65488 date=1525379338
the weather hasn't exactly been conducive to getting my confidence back again

Good health.

My regards, Bill
[/quote]
Stick with it Bill, it'll come. Best o luck....keep doing the physio💪
Cheers, Michael
Title: Re: Srx hard to start when warm
Post by: themoudie on May 04, 2018, 09:47:31 AM
Aye Michael,

What physio? NHS hasn't any capacity up here and the surgeon said "You know what to do, crack on!", so it's down to self help and bl**dy mindedness.  ;) Walking up to 4 miles a day and doing one leg squats seems to be doing the trick.

Starting a recalcitrant SRX will either make or break it, hopefully not the later!  :o

May I ask if you have been on tour yet? PM me if you would prefer.

Good health, Bill
Title: Re: Srx hard to start when warm
Post by: Moto63 on May 04, 2018, 04:49:40 PM
Evening Bill, when you say "tour" I assume you mean our Moffat long weekender??.... no mate it's all booked and we're raring to go but alas we'll have to wait until back end of august. The buccleuch arms was well booked up. Get in with the booking earlier next year has been the cry.😉.... regarding the physio, I ended up paying for some sessions as the NHS thing was frankly a joke. It was money well spent I must say. Yes keep walking, I did quite a lot of that as I wasn't allowed to drive for 6 months due to the brain injury....had to surrender my driving licence, oh and yes..I too was surprised there was enough in there to injure 🤣🤣🤕
Stay focused and best of luck... cheers, Michael
Title: Re: Srx hard to start when warm
Post by: themoudie on May 04, 2018, 06:44:13 PM
Are the Buckluck Hotel, that place can tell a few stories and I'm pretty sure I was leaving as you came down for breakfast the last time you stayed. That was afore my retirement. If you like your Indian, have you tried the wee one opposite?  ;)

As for the grey matter, I would never cast such aspersions about a fellow 'Thumpeteer'!   ;)

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Danxup on May 05, 2018, 07:18:31 AM
Im sat at the side of the road with the 600.. first time ive took it on a decent run since i bought it .. i thought ill have a run out and then when i get back and its hot ill start looking for problems... the bike was going great .. but then the fuel starvation thing started to happen.. i switched to prime while still riding but eventualy she cut out .. waiting for aa.  I think shes gonna get thrown in the garage till next week the weather is so nice im going to go out on the 400
Title: Re: Srx hard to start when warm
Post by: Steve Lake on May 05, 2018, 07:57:05 PM
that's a bu55er Dan.... next time it happens, try opening the filler, might just be a vacuum building up if it's not breathing properly, still ...lovely day to be sitting in the quiet listening to nature going about it's business.....  :D
Title: Re: Srx hard to start when warm
Post by: Danxup on May 12, 2018, 09:26:18 AM
Now then chaps..
Ive had chance to mess with the 600 abit this morning.
The choke plunger was seized in.  I had to encourage it out with wd40 and a pair of pliers .. now its sorted and moving nicely.. ive replaced all the fuel lines i can get to without removing carbs including vacume pipe.  .. she fires up second kick ticks over lovley .. but apply trottle and she coughs and splutters like owt.. must be a blockage in the carbs.. hopefully get time to get them off this week and have a look see..  she starts when warm now at least .. must of been the choke thing.. cheers ill let you know how i go
Title: Re: Srx hard to start when warm
Post by: themoudie on May 12, 2018, 02:03:53 PM
 ;) Persistance!

It'll come right Dan.

Those carbs could be tight between the cylinder inlet stubs and the airbox and you may have to slacken everything off and gently wiggle! If the inlet stubs and airbox stubs are at all dry then treat them with a soaking of 'AmorAll Protectant' for a good 24hrs if possible. Makes them flexible and protects them from the effects of the fuel.

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: timbo on May 15, 2018, 09:24:31 AM
There is also a recipe involving Wintergreen oil on here somewhere, which also has a remarkable affect in rejuvenating tired brittle carb rubbers  ;)
Title: Re: Srx hard to start when warm
Post by: Danxup on May 19, 2018, 08:46:50 AM
Ey up chaps.. so this morning i had time to get the carbs off.. ive had the tank repaired and lined now aswel.. the float bowl had lots of brown and black bits in must be rust.. is it ok to blast out the carbs with the airline or could this damage the diaphragm? Same question for the fuel tap? Thanks guys
Dan.
Title: Re: Srx hard to start when warm
Post by: iansoady on May 19, 2018, 10:21:49 AM
I'd be cautious about using an airline near the diaphragm. I'd strip it completely and use carb cleaner on it. Some people reckon ultrasonic cleaners work but I haven't had any real success with my (admittedly noddy) small unit.
Title: Re: Srx hard to start when warm
Post by: themoudie on May 19, 2018, 09:11:49 PM
Aye Dan,

Usual problem with a machine that is laid up with manky or ethanol fuel and no stabiliser mixed through it. After my 'incident' I drained Sally's tank and sucked all remaining vestiges of fuel from the two pannier parts of the tank with a large syringe and pipe (See previous posts on lamb feeding syringes!).   ;)

Compressed air through all the little orifices, having removed the diaphragms. Cotton buds, with paper sticks( :-X), wooden cocktail sticks and brake cleaner for loosening the rust and other detritous. Brake cleaner may also perish the diaphragms (!).  :(  YOU HAVE BEEN WARNED! 

Again, I use the 'ArmorAll' on the diaphragms and massage it in with my fingers, gently! Watch your nails if you play guitar!  ;)  Wipe any surplus off after leaving for a few hours. Re-assemble with care and a little light machine oil (3in1) on all pivots, springs etc.

Re-install and before connecting up the feed from the petrol tap, insert a small filter between the tap and the carb, it will save you more grief, as will draining your tank if you are going to keep the bike off the road for more than 8 weeks; especially when condensation is likely to form in the tank.

I attach an image of the contents of the pannier parts of the tank of a Mono SRX that I unfortunately purchased!  :-[

Good health and my regards, Bill

[attachment deleted by admin]
Title: Re: Srx hard to start when warm
Post by: Danxup on May 21, 2018, 08:48:31 PM
This aft i gave the carbs a reyt good fettle. And got them back on .. bike fires up 3rd kick on prime and seems to run well.. the throttle works mint again .  Unfortunately not had time to take her ont road as im off on holiday tonight wit missus.. ill keep you posted.
Title: Re: Srx hard to start when warm
Post by: themoudie on May 21, 2018, 09:03:18 PM
Have a grand holiday Dan!  ;)

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Danxup on June 02, 2018, 05:00:19 AM
Morning guys.. back of mi hols .. the 600 is booked in for mot at 9 this morning ... she should pass then hopfully i can take her on abit of a run see how she fairs with since the carb clean out.. ill let you know how i go.. 🤤
Title: Re: Srx hard to start when warm
Post by: Danxup on July 02, 2018, 12:07:50 PM
Now then.  Been dead busy but went out for a decent run on the 600 last Tuesday when england played as roads were quiet.   She seems to go realy well now.. im going out again tonight after work hopefully last tues wasnt a fluke..  great weather for biked btw!! Also.. last time i went out on the 400 by the time i got home the battery didnt have even enough power to make the indicators work but bike was still running fine.. could this be the generator coil? Thanks guys
Title: Re: Srx hard to start when warm
Post by: themoudie on July 02, 2018, 02:20:08 PM
Aye Dan,

Check the generator, the rectifier and the battery, the latter should be first in line. Also check all the wiring including the 'Earth' wires for continuity. Electrickery is not a strong point of mine and SteveL whom is well versed in the black art and has been running tests on one of his own fleet maybe better to answer your queries. SteveH also is familar with this 'other' world and may chip in his pennyworth.

If the battery is duff, I would recommend a 'MotoBatt', they are no cheap, but hold up well to single vibes.

My electrician friend in IoM once said "Treat it as water running through pipes." to which my reply was that my plumbing always leaks!  :(

Cannot remember if I sent a copy of the SRX workshop manual pdf to you, if you need a copy PM me using the link on the left of this post, with your email address and I will forward you same.

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Moto63 on July 02, 2018, 03:24:08 PM
No Bill... plumbing is much harder. We don't av nice colour coded pipes to suss the job out. They're all this funny copper colour. Hot, cold, flow and return 😁👍
Title: Re: Srx hard to start when warm
Post by: themoudie on July 02, 2018, 03:48:30 PM
Aye Michael,

I wouldn't describe aged Italian wiring as "nice colour coded pipes" or wire for that matter. More a "tangled mass of faded plastic containing rotten verdigris covered copper". A bit like a plate of pasta with green pesto and the same capability to conduct electrickery!  ???

The same can be said of older Japanese wiring as well, in which case it would be "fine noodles with wasabi paste"!  ;)

Whilst copper coloured tubes just weep at the joints!  :(

Toodle pip, Bill
Title: Re: Srx hard to start when warm
Post by: Danxup on July 02, 2018, 05:12:21 PM
Thanks .. i know the battery is good so ill have to get my uncle in to check the other bits. as i also dont do wires.. ill let you know how i get on.. cheers!
Title: Re: Srx hard to start when warm
Post by: Moto63 on July 02, 2018, 07:32:14 PM
Ah but do you do copper pipes Dan??😁😁😁👍...My pipes don't weep Bill, but I do quite a lot, especially by the time Friday teatime comes round. Think it's the 39 years in the trade that's done it to me😢😢😉🤘. cheers, Michael
Title: Re: Srx hard to start when warm
Post by: Danxup on July 07, 2018, 06:16:49 AM
 Ey up ..   i done 40 mile on the 600 yesterday and she went like dream.. she also fires up easy when hot .. such good fun to ride! So it seems repair beadblast and lining the tank.. replacing all fuel lines and a reyt good strip down and clean of the carbs and un seizing the choke plunger was all that was needed.. thanks so much for all your help id still be scratching my head now.. thanks again... ill be enjoying the 6 this summer and will then be doing a full strip down restoration over the winter... as for the 400 hopefully my uncle will get to have  look at it next week .. 😁⚡
Title: Re: Srx hard to start when warm
Post by: Danxup on July 07, 2018, 07:12:17 AM
Oh and i put the irridium spark plug in too! Yesterday which seems to have helped with the starting!
Title: Re: Srx hard to start when warm
Post by: themoudie on July 07, 2018, 08:11:38 AM
Aye Dan, that all sounds positive and I agree that the Iridium plug appears to make starting more reliable.

As for tank restoration, do it yourself, if you can and be aware that I have seen POR15 not adhering. BUT and it is a very LARGE "BUT" I do not know if the preparation was done as well as it should before POR15 was installed? There is also this "experience" posted on the forum from 2013: Tank_refurbishment? (http://www.thumperclub.com/smf/index.php?topic=7157.msg47900#msg47900) Caveat emptor!

Sally threw an electrical wobbler yesterday, no indicators and what appears to be a direct short on the battery!  :(  So, all stripped out ready for investigation today. Still ran beautifully, thanks to the separate CDI.  ;D  Maybe I could borrow your Uncle? ;)

Enjoy the beastie.

My regards, Bill
Title: Re: Srx hard to start when warm
Post by: Danxup on August 11, 2018, 05:13:26 AM
Ey up .. im on the lookout for a new tank for the 400.. damn thing has bubbled the paint again.. i should of binned the tank in the beginning but was too impatient to spend time finding a solid one .. the bloody thing is mostly filler it weighs  twice a normal tank.. it was my  first restoration lesson learned.. the guy who painted it made it look a million dollars  . And to be fair he said if i hadnt allready spent a small fortune on getting it plated and lined he would of told me to scrap it...  im in no rush this time . Ive put a message on the wanted bit but thought id pick your brains too as you was so helpful in getting my 600 sorted.. thanks guys...
Ohh and the 600 has been blowing indicator bulbs had uncle Graham round he said it was the rectifier .. replace that and its been sound since ..
Cheers  🤯