won't run with K&N's on unless on full choke

[Greenbraes]

Hi guys...I am at a point I want to run the bike round the block just to make sure the engine doesn't need anything major doing to it before I paint it. The bike has sat for about 17 years and now runs OK without any filters on it. The K&N's were put on and it now will only fire when on choke. Took the filters of and it fired up fine. I have a 4-1 pipe on it and 120 jets in the carbs. Any ideas?

RB

[John Kat]

The K&N pods on a GS 1000 typically require main jets around 165 to 170.
These come with the stage 3 Dynojet kit.
However it doesn't explain your issue...
Have you cleaned the carbs?
If the bike has been sitting for 17 years it's a must

[Greenbraes]

Hi John Kat
the carbs have been cleaned, I do have a completely overhauled set to go on after the engine is cleaned up and painted. I have put 122.5 jets in these under advice from a few guys on here as a starting point, I may have picked them up wrong but the largest jets available for the CV carbs I can find are 160. My plan is to get the bike running well enough to go for a run just to check out the engine, after that the engine comes out for paint, valve/shims are checked and overhauled carbs go on and get tuned.
cheers for getting back to me

RB

[OldVet66]

Can't see your thumbnail very well but it looks like you have replaced the tank, Suzuki silver? The carbs require a total strip down, soaking in carb dip, O-rings replaced, etc. The Dynojet stage three kit is the way to go with the jetting. The needle taper is superior for pipes and pods. It's still not a walk in the park to get them dialed in. There are a few bikes that have no kit for them. If you read some of the threads on dialing in a GS750, you might change your mind and get the jet kit. The Dynojet mains are numbered differently, but for your VM carbs on the '79 they supply one marked in the 130's (can't remember exactly) and a 142. The smaller jet usually works. Your picture reminds me of my tricolor bike/work in progress before painting, or is that a picture of another bike?

[GateKeeper]

a slightly larger picture of his bike

[OldVet66]

I have to question why you want to go through all that jetting hassle when you have the air box. Having been through it, I'd settle for jetting for the pipes, and keep the air box.

[Greenbraes]

couple of photos from today....excuse the mess in the garage..lol



and



RB

[Dave8338]

Have you checked your valve clearances?

As for the starting better without the filters, that is a puzzle. O-rings between the boots and the head replaced yet?

[Greenbraes]

boots have been removed checked and new O rings....carbs cleaned and have new O rings too. I was holding back on checking the valves until I knew the engine was sound, basically after a run. I have as a starting baseline the fuel mix screws 1 turn out and the air mix screws 2 turns ( have tried adjusting the air screws when running with no success when the filters are on)
cheers for the feedback so far

RB

[Dave8338]

A 4-1 pipe and pods is going to require a complete rejet and reset.

As mentioned, the stage 3 kit from DJ is your best bet to get the bike in the correct window. Fine tuning can be done from there.

My bone stock 850 is running 120 jets. Me thinks you need to bump your up just a bit.

Here is a source I use when playing with carbs for others' projects:

http://www.jetsrus.com/a_jet_kit_street/suzuki_1000_GS1000C-EC-N-EN_1978-1979.htm

[MisterCinders]

If the bike starts with no pods and needs choke to start with pods, something is rotten in Denmark.

Are your pods (somehow) blocking one of the passages feeding the choke or pilot system? Like one of the air holes on the air intake side of the carbs?

Where are your pilot screws set currently? Before you go painting that engine, you probably need to establish a better baseline.

Check and adjust your valves.
Clean the carbs (strip, dip, new o-rings from Barr)
Check the intake boots and o-rings. Replace the o-rings for sure, and the boots if they are hard or cracked.
Clean and re-oil (lightly) the pods.
Replace the exhaust gaskets (these are cheap and easy to do)
With happy valve clearances, vacuum synch the carbs.

Then start tuning from the pilot up. Set the fuel screws to about 7/8 and the air screws at twice that. You should be OK with the stock 15 pilot jet, but if you cannot get a good idle without opening the fuel screw beyond about 1.5 turns, you may need to bump the pilot screw up one size to 17.5.

While you are tuning the idle, move the needle clip down to the 4th slot and stick with the 120 main jets, which are much bigger than the stock 102.5s. These may slightly off, so pick up a set of 117.5 and 122.5 mains for later. You can dial them in once the pilot circuit and needle circuit are tuned.

[Greenbraes]

Thanks for the procedure MisterCinders, I have done some of the suggestions already, the only thing I was really going to hold on was the valve clearances until I knew the engine was sound, if it needs a rebuild it would just save some time was my thinking. Anyway I'm off back to work tomorrow at 4:00am for 2 weeks so will be getting back into the issues went return. Thanks again for all the feedback

RB

[hampshirehog]

Are they 26s or 28s on there Roy?

[Greenbraes]

good question.......have never thought about identification....any pointers..lol

here is one in bits



RB

[hampshirehog]

good question.......have never thought about identification....any pointers..lol

here is one in bits



RB

That narrows it down to one or the other......

The only way to tell is to measure the internal diameter on the inlet (head) side.