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Post by gs1000simon on Oct 1, 2014 12:58:40 GMT
Ok so got the gs1000 running to a degree.
At present ive got a set of 36mm gsxr carbs which appear to have been dyno jetted running k&n's. The engine has had some top end work aswell so was aware it was going to be a nightmare.
Anyways the bike will idle fine and startup with no issues. As soon as you try and pull away it bogs down and dies. With the choke on full or half it will run and run relatively well. I whipped one of the plugs out after playing around with jets and the needles and they are starting to turn sooty.
iirc im sure its 133's that are in at present
My best guess is that there isnt enough fuel getting in as it runs better with the choke on or too much air.
Any advice or pointers greatly apreciated
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Post by thorgrimm on Oct 1, 2014 18:37:03 GMT
Hi mate sounds like Overly rich fuel/air mixture, dirty air filter, idling for a long time. If the plugs are dry ,black and sooty check your emulsion tubes as the dj needles turn them oval and could cause what your describing. Check the tiny o ring in the top under the plastic cap, these can cause probs. You may have to play around with the clip position too. I'd also check valve clearances if you haven't done it. The dual pods work better than single kn filters. Bench sync is essential followed by carb balance after you've sorted out the prob. Allensperformance sells emulsion tubes at a good price. Hope that lot helps just doing the same to a gsx1100 with bst36 carbs
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wraith
Tyrannosaurus Rex
anything can be done
Posts: 139
Bikes: Katana 2x GS1000
Reg: May 2, 2014 17:50:13 GMT
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Post by wraith on Oct 3, 2014 17:29:37 GMT
I'm using a set of gsxr750k (slingshot) carbs on my GS1000 (ported head, 1100cc big bore,Harris pipe & race baffel) dual pod K&Ns air mixture set to standerd (1 3/4 I think same as in book LOL)144 main jets but going to be putting 150 in as it bogs abit after 6000 rpm. So I'd cheque the air mixture screws, cheque the carbs are clean inside (had mager probs with sh*t in the air mixture tube at one point)as a starting point. What carb rubbers are you using? (I've got B12 on mine) have you got a good seal on them?
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Post by nw66 on Oct 4, 2014 11:03:11 GMT
get a set of keihin Cr's(Allen's performance) easy to work with you be glad you spent the extra because you'll be riding your bike instead of pulling your hair out trying to get it to run properly probably forever
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Post by gs1000simon on Oct 4, 2014 19:44:08 GMT
Thanks for the info
On the engine side its been a complete rebuild so clearences are spot on, the filters are brand new aswell.
Carbs have been synced aswell already as said bike will idle away no problems.
The carb rubbers on the bike are a set I got with the head when upperton machined the inlets to take tube type opposed bolt on, and they are also brand new. Wraith my engine build sounds pretty similiar in spec.
NW66 would love to be able to buy a set unfortunatly not the flush took alot of scrimping to get what i have.
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Post by bigkenx on Oct 4, 2014 19:51:57 GMT
It's a matter of double checking just because something's new doesn't mean it's right you can buy four spark plugs and one can be fucked , check for air leaks , float height double check pilot system clean , flow on fuel tap , balence of carbs , then electrical system is ignition breaking down , coils etc only try one thing at a time to make sure you can eliminate it then your talking playing with jets .
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Post by nw66 on Oct 5, 2014 13:42:11 GMT
Good luck mate
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wraith
Tyrannosaurus Rex
anything can be done
Posts: 139
Bikes: Katana 2x GS1000
Reg: May 2, 2014 17:50:13 GMT
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Post by wraith on Oct 5, 2014 16:22:17 GMT
One more thing it may be... Is the timing set right on the points side -and as it's not running right over 3000rpm, is the ATU working i.e is it advancing? I have had the ATU stick and the bike will run ok at low rpm but will not run properly over 3000rpm. Cleaned it up, and the bike ran well.
As regards carbs, from what you originally described I'd be surprised if it's primarily a main jet issue. I've had a lot of hassle with various gsxr carbs last couple of years on various spec gsxr/gs engines, all at bottom end/starting/rough running. Generally all been sorted out with a mix of replacing old/contaminated fuel, really properly stripping and cleaning every carb part with tiny toothcombs (many, many times!), refurbing vacuum taps or clearing breathers on tanks, cleaning fuel lines & filters, fiddling around with pilot and idle jet & screw settings (a lot!) and balancing up carbs (a quick diy job did absolute wonders when I was convinced that it was all sorts of other carb problems!) Make sure that you get the idle/pilot jet/screw settings spot on before you start thinking about mains. Technically (though I don't personally think it's this black & white) main jets shouldn't really make a difference till, say, 1/3rd-1/2 throttle really. OK, needle heights, needle taper and so on could be an issue, as could floats and all sorts of other things, but if it's bogging as soon as you try to pull off, it sounds much more lower down the fuel/carb operation.
Or, have you got enough fuel coming through the petrol tap itself? Maybe replace with a Pingle or a gsxr one of some kind?
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Post by locomotion on Oct 5, 2014 20:53:45 GMT
I have rs36s on my 1000 engine and they are running 120 mains
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Post by katana on Oct 6, 2014 7:01:38 GMT
750K carbs? Weren't they 38mm? If so i'd say even with you mods you are waaaaay over carbed! The bogging and big jet numbers are a symptom of poor airflow - Suzuki fitted 34mm carbs for a reason......probably 36's would be optimal even for a race bike.....Just my opinion!
Edit Just Wiki'd it and 'K' had 36mm CV's but could still be a problem - I only had 136 MJ in 36mm CV's on a modded GSXR 1186
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wraith
Tyrannosaurus Rex
anything can be done
Posts: 139
Bikes: Katana 2x GS1000
Reg: May 2, 2014 17:50:13 GMT
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Post by wraith on Oct 7, 2014 18:35:11 GMT
750K carbs? Weren't they 38mm? If so i'd say even with you mods you are waaaaay over carbed! The bogging and big jet numbers are a symptom of poor airflow - Suzuki fitted 34mm carbs for a reason......probably 36's would be optimal even for a race bike.....Just my opinion! Edit Just Wiki'd it and 'K' had 36mm CV's but could still be a problem - I only had 136 MJ in 36mm CV's on a modded GSXR 1186 Yes the 750k had 36mm the latter 750L had the 38mm carbs, been playing with the timing and jetting on my GS1000 (36mm carbs) timed it with a strob light and put 136 main jets in and it gose like a rocket to say LOL pulls all the way throw the revs and is giving a much better porfamce than it did with the GSXR1100J carbs (34mm) and they where good.
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Post by katana on Oct 8, 2014 18:51:21 GMT
Glad its resolved with a good result - sometimes less is more!
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Post by bigkenx on Oct 8, 2014 18:53:55 GMT
Good job mate
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Post by gs1000simon on Oct 9, 2014 12:45:19 GMT
Cheers for the advice hopefuly get a chance to get at it soon, as the bikes at my dads or maybe he will read this and take a stab at it.
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wraith
Tyrannosaurus Rex
anything can be done
Posts: 139
Bikes: Katana 2x GS1000
Reg: May 2, 2014 17:50:13 GMT
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Post by wraith on Oct 19, 2014 18:29:26 GMT
Any joy with the bike mate?
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