Low end power up to 3500rpm horrible

[scooter6148]

I have a 1981 GS1100e..I inherited it last year from my Dad and it had set for around 7 years. Visibly it had a SuperTrap 4-into-1 exhaust system and noticed it probably did not have the stock plug wires because they were yellow. Anyway I had to pull the tank and carbs and clean them up. I bought rebuild kits for all 4 carbs and was told by one of my Dad's friends that it was jetted. As I rebuilt each carb I compared jet sizes I took out and only the main jet was different than was in the kit so I reused it on the rebuilt carbs. After putting carbs back on the bike and finally getting it running it seemed to pop out the exhaust quite a bit. I messed around with the air/fuel ratio screws but nothing seemed to change. So I took it to a local motorcycle shop to have the carbs synced and they came back with the exhaust gaskets were leaking and needed replaced so I had them do that. After they replaced the gaskets it was still not right and they found a leaky head and cylinder base gasket (argh!!) which was a big expense. I went ahead and let them do that and new rings since I paid $0 for the bike. After that was fixed they pointed out the jets were not right in the carbs. They ordered a Stage 3 jet kit but it still was not running correctly on Cylinder 1. They tried moving plug wires but issue stayed on Cylinder 1. They tried a set of other coils (stock) and did not work at all. So yes I spent more money and they put new coils on it. They finally said it was ready to pick up. When I drove it home it was horrible from idle to get moving without having to constantly goose the throttle until I got moving. After 3500 rpm the power was awesome but the popping was still there...I called the motorcycle shop and told them I was unhappy and it seemed was no different than when I brought it in 2 months ago (yes 2 months). I ended up taking it back and leaving it overnight. The next day I talked to the owner and he explained several things about the bike. Someone had already been into the motor and the cams were put back 1 tooth off and an aftermarket ignition was added (hence the non-stock coils). They thought the cam off one tooth may have been causing the popping but nothing changed. They had issues getting info on the exhaust for proper jetting but the manufacturer stated they had not made that system for 15 years and had no info on it. They called DynoJet and got what they needed for the jetting but they never changed the pilot jet per recommendation of SuperTrap and DynoJet...I did some research before this post and I am seeing people change the pilot jets which would make sense that the power from idle to 3500 is horrible. The motorcycle shop stated the reason not to change pilot jet was the reservoir between the main and pilot jets is one size and increasing the pilot jet would not do any good. Then why have the jet if the reservoir is only the size of the stock jet? I'm asking the shop to entertain the idea of changing the pilot jet now because it is so horrible from idle to around 3500rpm? What does anyone else think I should do? I have a lot of money in this that I won't get out of it...The other solution they have is getting a rack of carbs from a 91-92 GSX1100 that are setup differently and is more adjustable for the pilot jet. I'm at a loss here and have been banging my head on the Internet trying to find a clear answer. I have seen several people on forums changing pilot jets so I don't understand why the shop is telling me they were told not to..Any help would be appreciated!!

 

[Steve]

First of all,

Second, consider yourself very lucky that you found a shop that will even let your bike in the door.

Third, I really wish I had all the money that you used to have before working on the bike.



There is a very good reason why we advocate doing the work yourself. You will KNOW what has been done, and HOW. If there is something that you don't understand, this is the place to ask.

Also, where are you? There is a decent-enough chance that one (or more) of us is close enough to help.

.

 

[tom203]

Wow! I understand your need for a complete explanation, but lots of us have short attention spans! Firstly, did it run right for your dad?
Getting it to run right as you transition from idle circuit (that pilot jet stuff) to main jet is tricky. There are lots of variables (main jet size, needle taper, air flow (filter element), etc. I think your shop was trying to be fair with you (as they took your money), but you really need to do this work yourself. Spend some time on this forum and its links- understand this work ain't for everyone, but hey it's your dad's old bike so buckle up.

visit here... and be amazed
http://members.dslextreme.com/users/bikecliff

 

[John Kat]

Before going any further, I would recommend you look at the position of the needles.
If your bike idles OK the pilot jet is close enough for the moment.

 

[posplayr]

I would determine what was in the carbs when you got it and post that back here.

What main jets
What pilot jets
What needles and what setting

Pods?

You have already stated a Supertrapp.

What is in there now after the K&N kit?

Also rebuild kits from K&L are not recommended , It is best to stay with the Mikuni jets or DJ kets from the kit. An remember DJ numbers are about 10 higher for teh same jet size as an equivalent Mikuni.

The mechanic is going to soak you if your keep going back.

How did he change a base gasket and then tell you that the cam chain is still off by one tooth?

Pull the carbs off and send them to Chef1366; he will set them up close and review what work has been done by this mechanic.

 

[Big T]

The mechanic is going to soak you if your keep going back.

How did he change a base gasket and then tell you that the cam chain is still off by one tooth?

Pull the carbs off and send them to Chef1366; he will set them up close and review what work has been done by this mechanic.

Very good question

Just how did he manage to pull the cams and reset them one tooth off, then tell you that was the problem?

 

[Good Times]

Welcome to the forum scoot.

What a frustrating experience. I agree. If they changed the base gasket out then they would have been the ones that put the cam back in wrong.

I would take Steve up on his advice and see if there are any GS'ers close by. These bikes are not hard to work on, BUT you have to know how they work. For instance, it's best to order a set of orings from cycleorings.com when rebuilding the carbs. The orings on the intake boots and the intake boots themselves are also vital to the bike running well.

Take some time and read up on BassCliff's site and if nothing else you will be educated if you take it back to the shop (which is an option most on the site will encourage you not to do).

Good luck!

 

[scooter6148]

Thanks for the warm welcome all!!

To clarify, they told me someone else had been in the motor once before and that that the chain was set 20 teeth and should have been 21 teeth. When I got the bike, I noticed one of the OHC cover bolts was not seated and pulled it. I compared the depth of some of the other bolt holes and found the one that should have been it's place. I swapped both of them and all was good...except there were 2 bolts missing on the rear side of the cover were the breather connects to the air box..the shop was supposed to replace the bolts. After I pointed out they were missing then they said they were broke off...they did end up fixing them. So someone else before I even got the bike was in the motor.

Since I picked up the bike on Friday I filled the gas tank, drove it home and drove it in my neighborhood a little on Saturday, it has developed and new problem and I found other issues the shop pointed out that were a problem when I worked on it and brought it to them. First, the bike sat on it's kickstand overnight since yesterday and my wife and I were both smelling raw gas. I looked at it before lunch today and noticed a puddle on the floor that looked like oil. I thought it was the base cylinder gasket because of the color. Later I checked it again but it smelled like gas. After further review I found the carb all the way to the left while sitting on the bike was soaked with gas and dripping down the side. to alleviate the issue I put the bike on it's center stand. Then gasoline started coming out of the airbox vent tube (WTF!) so I put a drip pan under hoping it would drip a little more and stop. I stepped out for a couple hours and came back to it still dripping!!(OMG) I dumped about a half inch of gas in a 9 x 13 baking pan!! So I started messing with the gas tank petcock..I turned it to Pri and it still continued to drip so I turned it to Res and it slowed and stopped dripping. Later I put my weight on the back of the bike so the back tire touched and more gas dripped out of the airbox vent tube. So I'm not sure now what is causing that...stuck floats? I put all new float valves in all the carbs..what have they done?!!

The next thing I found when I brought it in they told me not having the boots from the airbox to the carbs fully seated on the carbs can cause additional air to be sucked in causing it to not run properly. I looked at all the boots and one of the two inner carbs did not have the boots on the carbs all the way seated forward up against the carb..What! Then there is a tube, I assume is a breather tube, that runs from one of the inner carbs to the gas petcock. When I put the tube back on the gas petcock I used a zip tie on the tube to secure it to the gas petcock and seal it since it seemed to make a difference on how it ran when I worked on it. The zip tie was not there so possibly more air was being sucked in around that hose..very disappointing.

I guess this a lesson learned..as the ol' saying goes "you want something done right you have to do it yourself". I'm calling the shop tomorrow and demanding they either pick up the bike (no way I'm driving it that way) and fix it the way it should be and running right at all RPM's or give me my $2K I spent back. The owner already offered that Friday if I drove it for the weekend and still was unhappy on Monday. I talked to them on Saturday and hoped we could work on this carb issue and change pilot jets to hopefully get it running to my satisfaction...now I'm not so sure.
I'll let everyone know how it goes tomorrow...If they refund my money I will utilize everyone's advice on this thread to do it myself. I'll probably send carbs to Chef1366 as advised and employ what resources from this site from now on so I can to finally start riding this bike!! This has already been a 6 month project spending almost $3K in parts and repairs!! Thankfully I paid $0 for it...

 

[Guest]

Welcome to GSR!

I feel your pain.

Obvious evidence that the mechanic doesn't know enough to work on your GS:

Your GS leaks gas now and did not leak gas before you took it to the shop.
The carb boots were not properly seated.
The GS has a new oil leak.
​

This doesn't even include that the original problems were not fixed.

It is quite possible that the mechanic is younger than your GS and does not have a manual for it. He probably has not been trained to work on any bikes from the 19800s.

Again, where do you live?

Members can help you better if you post digital pictures. Several hosting services let you upload photos to their site. The hosting service gives you a URL for each photo. Copy that, and paste it into your message, and we can see what you have.

 

[koolaid_kid]

I strongly suggest that you be very polite with them and just ask for your money back, since he already made the offer. Thank him politely and get the check and deposit it. Make it a win/win situation. Demands, anger, shouting, all these things make it very easy for him to hang up and keep your money despite the fact that his shop failed to perform the job properly.
Then tell us where you live (in your profile) and we will see if someone can come over and assist. And if the coils that were with the yellow wires are also yellow, they are Accel, which is what I use on my GPz.

 

[Steve]

Your next lesson will be "How to use the petcock". :-k

Normally, the petcock lever should point straight DOWN, in the RUN position. That is where it should be when you park the bike and when you ride the bike. When the engine is running, vacuum will turn the petcock ON and fuel will flow. When the engine is stopped, vacuum will stop and the fuel flow will stop.

If, while riding the bike, you start running out of gas, move the lever FORWARD (rotate clockwise) to put it into the REServe position. That will let you use the last gallon or so in the tank to find the next gas station.

If, by some chance, you have not ridden the bike for several weeks, or have done some carb work and the bowls are empty, move the lever REARWARD to the PRIme position. In that position, gas will flow freely to the carbs, and not rely on the vacuum generated by a running engine to turn the petcock ON. WARNING!!! Do not leave the petcock in this position for more than a minute or so. You will easily forget it and leaving it there will remove one of the two methods of stemming fuel flow. (The other is the float valve in the carb.) As you have seen, leaving the petcock in PRIme can easily cause the carbs to overflow.

.

 

[scooter6148]

The petcock has been in the Run (down) position the entire time before this gas leak issue...I didn't change the petcock until the baking pan filled up a half inch and is now in the Res position and dripping has stopped..

I am in Lafayette, Indiana...

Thanks for the lesson....this is my first street bike and I'm used to On/Off/Reserve...never saw Prime before. Thanks.

 

[scooter6148]

I would determine what was in the carbs when you got it and post that back here.

What main jets
What pilot jets
What needles and what setting

Pods?

You have already stated a Supertrapp.

What is in there now after the K&N kit?

Also rebuild kits from K&L are not recommended , It is best to stay with the Mikuni jets or DJ kets from the kit. An remember DJ numbers are about 10 higher for teh same jet size as an equivalent Mikuni.

The mechanic is going to soak you if your keep going back.

How did he change a base gasket and then tell you that the cam chain is still off by one tooth?

Pull the carbs off and send them to Chef1366; he will set them up close and review what work has been done by this mechanic.

All the jets on the carbs were done by shop so I don't have a clue what is in them now...When I rebuilt carbs I looked at each jet and replaced with new one from kit..I also used needle from rebuild kit as well. I did use K&L rebuild kits. No pods just K&N filter in stock airbox setup...new lid with new seal.

 

[scooter6148]

Wow! I understand your need for a complete explanation, but lots of us have short attention spans! Firstly, did it run right for your dad?
Getting it to run right as you transition from idle circuit (that pilot jet stuff) to main jet is tricky. There are lots of variables (main jet size, needle taper, air flow (filter element), etc. I think your shop was trying to be fair with you (as they took your money), but you really need to do this work yourself. Spend some time on this forum and its links- understand this work ain't for everyone, but hey it's your dad's old bike so buckle up.

visit here... and be amazed
http://members.dslextreme.com/users/bikecliff

I don't know if it ran right for my Dad...I didn't see him much in the last 7 years. I saw the bike at his house in his garage but we never discussed it. All his friends told me when he passed last year was that it was jetted and it was fast..

 

[posplayr]

All the jets on the carbs were done by shop so I don't have a clue what is in them now...When I rebuilt carbs I looked at each jet and replaced with new one from kit..I also used needle from rebuild kit as well. I did use K&L rebuild kits. No pods just K&N filter in stock airbox setup...new lid with new seal.

I got all that the first time

 

[scooter6148]

Your next lesson will be "How to use the petcock". :-k

Normally, the petcock lever should point straight DOWN, in the RUN position. That is where it should be when you park the bike and when you ride the bike. When the engine is running, vacuum will turn the petcock ON and fuel will flow. When the engine is stopped, vacuum will stop and the fuel flow will stop.

If, while riding the bike, you start running out of gas, move the lever FORWARD (rotate clockwise) to put it into the REServe position. That will let you use the last gallon or so in the tank to find the next gas station.

If, by some chance, you have not ridden the bike for several weeks, or have done some carb work and the bowls are empty, move the lever REARWARD to the PRIme position. In that position, gas will flow freely to the carbs, and not rely on the vacuum generated by a running engine to turn the petcock ON. WARNING!!! Do not leave the petcock in this position for more than a minute or so. You will easily forget it and leaving it there will remove one of the two methods of stemming fuel flow. (The other is the float valve in the carb.) As you have seen, leaving the petcock in PRIme can easily cause the carbs to overflow.

.

What would cause the leak if the petcock was on Run? Only thought I had was a stuck float.

 

[gearhead13]

So, the shop said it was supposed to be 21 teeth? They are wrong, 20 teeth is correct
If you didnt replace all the o-rings in the carbs, then thats why they are leaking, get an o-ring kit from Cycle o-rings. It sounds like your petcock isnt working properly either. Check your engine oil for gas, it can leak into the engine. Open the oil fill plug and smell for gas and check the oil level to see if it is overfull because of the added gas.

 

[cowboyup3371]

What would cause the leak if the petcock was on Run? Only thought I had was a stuck float.

Your petcock could have failed. Please don't try to rebuild it as most rebuild kits don't work well. Get a new one from Z1 Enterprises that matches your bolt settings

 

[tom203]

Your petcock could have failed. Please don't try to rebuild it as most rebuild kits don't work well. Get a new one from Z1 Enterprises that matches your bolt settings

Yeah, just get a new petcock (maybe $60) and rule it out as a problem, then move on to carb repair fun. If you don't do this work yourself, it will very likely be done incomplete or wrong.

 

[scooter6148]

Called shop and discussed Cam links...owner says it was off spec and they set it to what it should be. Now saying wasn't sure which direction it was off but put it in spec now. Asked him to verify..discussed gas leak. He mentioned petcock and had me test in On position with fuel line off to see if it drips..nothing..petcock ok. My speculation on that at this point is, since I'm a newbie to this style of bike, that I may have positioned it to Pri for too long not understanding how that petcock positions worked..Thanks again for the lesson 'Steve"!! I did go ahead as a precaution and drained oil...smelled a little like gas when I opened the oil filler. Got fresh oil in it now.
While I had the tank propped up I zip tied the vacuum line that connects to the petcock from carb. Later on after work I fired it up after refreshing oil and took it for a spin..It seemed to be a little better now since I sealed up that vacuum line! I only rode it for a short time but from idle to start in first gear seemed better..I still need to seal up the airbox to the inner carbs better and drive it a little more before I let the shop change pilot jets in carbs. (Yes, I'm giving them one last shot at this before I take it over myself since I'm not paying anymore labor for this..)
Thanks for all your input on this!...although it's not over yet I feel comfortable that after I cut ties with the shop that I have some better support on my GS1100e..