Shogun High Rev Problem - xBhp.com : The Global Indian Biking Community

Coolkar · 08-15-2009, 12:19 PM

Hi ppl,

My name is Karthikeyan Manga, from Chennai. I am a proud owner of TVS Suzuki Shogun (99 model). For the past 2 months I have been busy overhauling ma Shogun. I have kept aside the stock cylinder and gearbox. Instead I have installed a 1mm oversized bore running on 5 gears (Of Shaolin Gearbox). For those wondering the point in doing so is that I was quite curious to atleast emulate how the Shadow version of Shogun would have felt like as well as to quench ma hunger for some more power. Now, everything should have worked out well by theory until this happened. After achieving 7500 rpm, the bike starts to miss its beat. That is, the bike begins to choke or 'dump'. After that ma Shogun struggles to gain further speed after this RPM. But till 7500 rpm, I could feel significant improvement in acceleration and reach 105 kmph at this RPM in the last gear. When consulted with various mechanics, The following factors were summarised that could be the reason for the above problem:

1. Damage in sleeve while reboring/porting. The exhaust port is widened keeping the inlet port intact.

2. Problem in Magneto

3. Due to CDI unit.

4. Maybe due to the usage of NGK Iridium Spark Plug instead of the stock Champion plug.

As far as ma stock 4-speed Shogun is concerned, I had no problems from the CDI and the Magnet coil. The speedometer used to indicate 115kmph when the bike's in full song. I am using a 97.5 main jet in the Carburettor.

I will be more than delighted if you Xbhpians could help me sort out this issue.

Cheers,
Karthik.

Aryan · 08-15-2009, 02:32 PM

Query Approved.

Coolkar · 08-15-2009, 04:59 PM

I would like to add to the fact that this 'dump' problem @ 7500 rpm not only occurs in the 5th gear, but in all the gears.

_keerthy · 08-16-2009, 08:44 PM

Please do a Spark plug reading ant see what color it is. I think it might be running lean. Have you done a run in? Why do you use an Iridium plug? An ordinary copper electrode plug is fine enough.

Aditya.. · 08-16-2009, 09:07 PM

Quote:

Originally Posted by Coolkar

Hi ppl,

My name is Karthikeyan Manga, from Chennai. I am a proud owner of TVS Suzuki Shogun (99 model). For the past 2 months I have been busy overhauling ma Shogun. I have kept aside the stock cylinder and gearbox. Instead I have installed a 1mm oversized bore running on 5 gears (Of Shaolin Gearbox). For those wondering the point in doing so is that I was quite curious to atleast emulate how the Shadow version of Shogun would have felt like as well as to quench ma hunger for some more power. Now, everything should have worked out well by theory until this happened. After achieving 7500 rpm, the bike starts to fade. That is, the bike begins to choke or 'dump'. Ma Shogun struggles to gain further speed after this RPM. But till 7500 rpm, I could feel significant improvement in acceleration and reach 105 kmph at this RPM in the last gear. When consulted with various mechanics, The following factors were summarised that could be the reason for the above problem:

1. Damage in sleeve while reboring/porting. The exhaust port is widened keeping the inlet port intact.

2. Problem in Magneto

3. Due to CDI unit.

4. Maybe due to the usage of NGK Iridium Spark Plug instead of the stock Champion plug.

As far as ma stock 4-speed Shogun is concerned, I had no problems from the CDI and the Magnet coil. The speedometer used to indicate 115kmph when the bike's in full song. I am using a 97.5 mm main jet in the Carburettor.

I will be more than delighted if you Xbhpians could help me sort out this issue.

Cheers,
Karthik.

Dude the shadow was probably a 135 or a 140 cc engine ..emulating that would be nearly impossible on a shogun as the 110 version itself is quite stressed.AFAIK it was based on the shaolin cylinder
anyway the blocking might be due to the magneto.or running a very rich mix.check the carb .
not sure karthik lets wait for the experts to comment on this

Coolkar · 08-16-2009, 09:23 PM

Thank you Keerthy for your advice. I will be happy if you could enlighten me more on this spark plug issue. Firstly, what do you mean by 'spark plug running lean' ? What are its causes? Secondly what is a 'run in'? Anyway will let you know if there is any improvement by changing the plug to stock by tomorrow. Thank you once again.

_keerthy · 08-17-2009, 09:17 PM

Karthik, please go through some old topics. You will find all your answers there.

Your spark plugs dont run lean, it is the air and fuel mixture that has got to be lean. You can find if the mix is rich or lean by looking at the spark plug. You will only get a rough idea though. An engine that is set up right, will have a plug with brown coloring. If it looks lightish in color, then it says the engine is running lean.
Once again, please go through the old topics. You will find plenty of tips in them.

Joel · 08-17-2009, 09:31 PM

The Shadow was a 138cc bike with a 5-speed GB. FYI, We have a shadow amongst us.
In your case, you need to start diagnosing the bike step by step.
1. switch to standard plugs
2. Check HT coil
3. Check CDI from another shogun
4. Electricals must be thorougly checked.

This has no relation to the fuelling or engine, it sounds purely electrical related.

_keerthy · 08-17-2009, 10:16 PM

^^ I wont be too sure about that anna. My bike has good electricals, but i still face a similar problem long time ago. It came down to fueling alone. I had a fouled plug every 500 or so kms. After sorting out the fueling issue, the bike revs clean. But that was just my case.
I am still facing problems coz of the bore kit. The porting is crappy in the so called original bore. The plug reads rich, or perhaps too rich on the boost side and a bit lean on the exhaust side.

Aditya.. · 08-17-2009, 10:58 PM

Quote:

Originally Posted by Joel

T
3. Check CDI from another shogun
.

joel one small query .does the cdi run on the battery?

08-15-2009, 12:19 PM	#1 (permalink)
Coolkar Shogun Join Date: May 2009 Location: Chennai-58 Posts: 49	Shogun High Rev Problem Hi ppl, My name is Karthikeyan Manga, from Chennai. I am a proud owner of TVS Suzuki Shogun (99 model). For the past 2 months I have been busy overhauling ma Shogun. I have kept aside the stock cylinder and gearbox. Instead I have installed a 1mm oversized bore running on 5 gears (Of Shaolin Gearbox). For those wondering the point in doing so is that I was quite curious to atleast emulate how the Shadow version of Shogun would have felt like as well as to quench ma hunger for some more power. Now, everything should have worked out well by theory until this happened. After achieving 7500 rpm, the bike starts to miss its beat. That is, the bike begins to choke or 'dump'. After that ma Shogun struggles to gain further speed after this RPM. But till 7500 rpm, I could feel significant improvement in acceleration and reach 105 kmph at this RPM in the last gear. When consulted with various mechanics, The following factors were summarised that could be the reason for the above problem: 1. Damage in sleeve while reboring/porting. The exhaust port is widened keeping the inlet port intact. 2. Problem in Magneto 3. Due to CDI unit. 4. Maybe due to the usage of NGK Iridium Spark Plug instead of the stock Champion plug. As far as ma stock 4-speed Shogun is concerned, I had no problems from the CDI and the Magnet coil. The speedometer used to indicate 115kmph when the bike's in full song. I am using a 97.5 main jet in the Carburettor. I will be more than delighted if you Xbhpians could help me sort out this issue. Cheers, Karthik. Last edited by Coolkar; 08-17-2009 at 04:20 PM. Reason: For clarity

08-15-2009, 02:32 PM	#2 (permalink)
Aryan Senior Member Join Date: Jan 2006 Location: New Delhi/ Shillong Posts: 18,274	Query Approved. __________________ ...in search of that perfect world - My Travel Blog :)

08-15-2009, 04:59 PM	#3 (permalink)
Coolkar Shogun Join Date: May 2009 Location: Chennai-58 Posts: 49	Shogun High Rev Problem I would like to add to the fact that this 'dump' problem @ 7500 rpm not only occurs in the 5th gear, but in all the gears. Last edited by Coolkar; 08-15-2009 at 07:44 PM.

08-17-2009, 09:31 PM	#8 (permalink)
Joel Race Concepts Join Date: Jun 2004 Location: Bangalore Posts: 1,844	The Shadow was a 138cc bike with a 5-speed GB. FYI, We have a shadow amongst us. In your case, you need to start diagnosing the bike step by step. 1. switch to standard plugs 2. Check HT coil 3. Check CDI from another shogun 4. Electricals must be thorougly checked. This has no relation to the fuelling or engine, it sounds purely electrical related. __________________ joel@raceconcepts.in

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08-16-2009, 08:44 PM	#4 (permalink)
_keerthy Senior Member Join Date: Sep 2008 Location: Coimbatore Posts: 111	Please do a Spark plug reading ant see what color it is. I think it might be running lean. Have you done a run in? Why do you use an Iridium plug? An ordinary copper electrode plug is fine enough.

08-16-2009, 09:23 PM	#6 (permalink)
Coolkar Shogun Join Date: May 2009 Location: Chennai-58 Posts: 49	Thank you Keerthy for your advice. I will be happy if you could enlighten me more on this spark plug issue. Firstly, what do you mean by 'spark plug running lean' ? What are its causes? Secondly what is a 'run in'? Anyway will let you know if there is any improvement by changing the plug to stock by tomorrow. Thank you once again.

08-17-2009, 09:17 PM	#7 (permalink)
_keerthy Senior Member Join Date: Sep 2008 Location: Coimbatore Posts: 111	Karthik, please go through some old topics. You will find all your answers there. Your spark plugs dont run lean, it is the air and fuel mixture that has got to be lean. You can find if the mix is rich or lean by looking at the spark plug. You will only get a rough idea though. An engine that is set up right, will have a plug with brown coloring. If it looks lightish in color, then it says the engine is running lean. Once again, please go through the old topics. You will find plenty of tips in them.

08-17-2009, 10:16 PM	#9 (permalink)
_keerthy Senior Member Join Date: Sep 2008 Location: Coimbatore Posts: 111	^^ I wont be too sure about that anna. My bike has good electricals, but i still face a similar problem long time ago. It came down to fueling alone. I had a fouled plug every 500 or so kms. After sorting out the fueling issue, the bike revs clean. But that was just my case. I am still facing problems coz of the bore kit. The porting is crappy in the so called original bore. The plug reads rich, or perhaps too rich on the boost side and a bit lean on the exhaust side.

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